add webserver components, some webserver fices and improvements in templating, add real time history chart

components/common_utils/CMakeLists.txt

@@ -0,0 +1,8 @@
+set(COMPONENT_ADD_INCLUDEDIRS include)
+
+set(COMPONENT_SRCDIRS
+        "src")
+
+#set(COMPONENT_REQUIRES)
+
+register_component()

components/common_utils/README.txt

@@ -0,0 +1,2 @@
+General purpose, mostly platofrm-idependent utilities
+that may be used by other components.

components/common_utils/component.mk

@@ -0,0 +1,3 @@
+
+COMPONENT_SRCDIRS := src
+COMPONENT_ADD_INCLUDEDIRS := include

components/common_utils/include/common_utils/base16.h

@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2010 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef BASE16_H_
+#define BASE16_H_
+
+#include <stdint.h>
+#include <string.h>
+
+/**
+ * Calculate length of base16-encoded data
+ * @param raw_len Raw data length
+ * @return Encoded string length (excluding NUL)
+ */
+static inline size_t base16_encoded_len(size_t raw_len) {
+	return (2 * raw_len);
+}
+
+/**
+ * Calculate maximum length of base16-decoded string
+ * @param encoded Encoded string
+ * @return Maximum length of raw data
+ */
+static inline size_t base16_decoded_max_len(const char *encoded) {
+	return ((strlen(encoded) + 1) / 2);
+}
+
+/**
+ * Base16-encode data
+ *
+ * The buffer must be the correct length for the encoded string.  Use
+ * something like
+ *
+ *     char buf[ base16_encoded_len ( len ) + 1 ];
+ *
+ * (the +1 is for the terminating NUL) to provide a buffer of the
+ * correct size.
+ *
+ * @param raw Raw data
+ * @param len Length of raw data
+ * @param encoded Buffer for encoded string
+ */
+extern void base16_encode(uint8_t *raw, size_t len, char *encoded);
+
+/**
+ * Base16-decode data
+ *
+ * The buffer must be large enough to contain the decoded data.  Use
+ * something like
+ *
+ *     char buf[ base16_decoded_max_len ( encoded ) ];
+ *
+ * to provide a buffer of the correct size.
+ * @param encoded Encoded string
+ * @param raw Raw data
+ * @return Length of raw data, or negative error
+ */
+extern int base16_decode(const char *encoded, uint8_t *raw);
+
+#endif /* BASE16_H_ */

components/common_utils/include/common_utils/datetime.h

@@ -0,0 +1,131 @@
+/**
+ * TODO file description
+ * 
+ * Created on 2019/09/13.
+ */
+
+#ifndef CSPEMU_DATETIME_H
+#define CSPEMU_DATETIME_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+enum weekday {
+    MONDAY = 1,
+    TUESDAY,
+    WEDNESDAY,
+    THURSDAY,
+    FRIDAY,
+    SATURDAY,
+    SUNDAY
+};
+_Static_assert(MONDAY==1, "enum weekday numbering Mon");
+_Static_assert(SUNDAY==7, "enum weekday numbering Sun");
+
+enum month {
+    JANUARY = 1,
+    FEBRUARY,
+    MARCH,
+    APRIL,
+    MAY,
+    JUNE,
+    JULY,
+    AUGUST,
+    SEPTEMBER,
+    OCTOBER,
+    NOVEMBER,
+    DECEMBER
+};
+_Static_assert(JANUARY==1, "enum month numbering Jan");
+_Static_assert(DECEMBER==12, "enum month numbering Dec");
+
+/** Abbreviated weekday names */
+extern const char *DT_WKDAY_NAMES[];
+/** Full-length weekday names */
+extern const char *DT_WKDAY_NAMES_FULL[];
+/** Abbreviated month names */
+extern const char *DT_MONTH_NAMES[];
+/** Full-length month names */
+extern const char *DT_MONTH_NAMES_FULL[];
+
+typedef struct datetime {
+    uint16_t year;
+    enum month month;
+    uint8_t day;
+    uint8_t hour;
+    uint8_t min;
+    uint8_t sec;
+    enum weekday wkday; // 1=monday
+} datetime_t;
+
+// Templates for printf
+#define DT_FORMAT_DATE   "%d/%d/%d"
+#define DT_SUBS_DATE(dt) (dt).year, (dt).month, (dt).day
+
+#define DT_FORMAT_TIME   "%d:%02d:%02d"
+#define DT_SUBS_TIME(dt) (dt).hour, (dt).min, (dt).sec
+
+#define DT_FORMAT_DATE_WK   DT_FORMAT_WK " " DT_FORMAT_DATE
+#define DT_SUBS_DATE_WK(dt) DT_SUBS_WK(dt), DT_SUBS_DATE(dt)
+
+#define DT_FORMAT_WK   "%s"
+#define DT_SUBS_WK(dt) DT_WKDAY_NAMES[(dt).wkday]
+
+#define DT_FORMAT_DATE_TIME   DT_FORMAT_DATE " " DT_FORMAT_TIME
+#define DT_SUBS_DATE_TIME(dt) DT_SUBS_DATE(dt), DT_SUBS_TIME(dt)
+
+#define DT_FORMAT   DT_FORMAT_DATE_WK " " DT_FORMAT_TIME
+#define DT_SUBS(dt) DT_SUBS_DATE_WK(dt), DT_SUBS_TIME(dt)
+
+// base century for two-digit year conversions
+#define DT_CENTURY 2000
+// start year for weekday computation
+#define DT_START_YEAR 2019
+// January 1st weekday of DT_START_YEAR
+#define DT_START_WKDAY TUESDAY
+// max date supported by 2-digit year RTC counters (it can't check Y%400==0 with only two digits)
+#define DT_END_YEAR 2399
+
+typedef union __attribute__((packed)) {
+    struct __attribute__((packed)) {
+        uint8_t ones : 4;
+        uint8_t tens : 4;
+    };
+    uint8_t byte;
+} bcd_t;
+_Static_assert(sizeof(bcd_t) == 1, "Bad bcd_t len");
+
+/** Check if a year is leap */
+static inline bool is_leap_year(int year)
+{
+    return year % 400 == 0 || (year % 4 == 0 && year % 100 != 0);
+}
+
+/**
+ * Check if a datetime could be valid (ignores leap years)
+ *
+ * @param[in] dt
+ * @return basic validations passed
+ */
+bool datetime_is_valid(const datetime_t *dt);
+
+/**
+ * Set weekday based on a date in a given datetime
+ *
+ * @param[in,out] dt
+ * @return success
+ */
+bool datetime_set_weekday(datetime_t *dt);
+
+/**
+ * Get weekday for given a date
+ *
+ * @param year - year number
+ * @param month - 1-based month number
+ * @param day - 1-based day number
+ * @return weekday
+ */
+enum weekday date_weekday(uint16_t year, enum month month, uint8_t day);
+
+
+#endif //CSPEMU_DATETIME_H

components/common_utils/include/common_utils/hexdump.h

@@ -0,0 +1,19 @@
+/**
+ * @file
+ * @brief A simple way of dumping memory to a hex output
+ *
+ * \addtogroup Hexdump
+ *
+ * @{
+ */
+
+
+#include <stdio.h>
+
+#define HEX_DUMP_LINE_BUFF_SIZ  16
+
+extern void hex_dump(FILE * fp,void *src, int len);
+extern void hex_dump_buff_line(FILE *fp, int addr_size, unsigned pos, char *line, unsigned len);
+/**
+ * }@
+ */

components/common_utils/include/common_utils/utils.h

@@ -0,0 +1,101 @@
+/**
+ * General purpose, platform agnostic, reusable utils
+ */
+
+#ifndef COMMON_UTILS_UTILS_H
+#define COMMON_UTILS_UTILS_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "base16.h"
+#include "datetime.h"
+#include "hexdump.h"
+
+/** Convert a value to BCD struct */
+static inline bcd_t num2bcd(uint8_t value)
+{
+    return (bcd_t) {.ones=value % 10, .tens=value / 10};
+}
+
+/** Convert unpacked BCD to value */
+static inline uint8_t bcd2num(uint8_t tens, uint8_t ones)
+{
+    return tens * 10 + ones;
+}
+
+/**
+ * Append to a buffer.
+ *
+ * In case the buffer capacity is reached, it is reverted to the previous length (by replacing the NUL byte)
+ * and NULL is returned.
+ *
+ * @param buf - buffer position to append at; if NULL is given, the function immediately returns NULL.
+ * @param appended - string to append
+ * @param pcap - pointer to a capacity variable
+ * @return the new end of the string (null byte); use as 'buf' for following appends
+ */
+char *append(char *buf, const char *appended, size_t *pcap);
+
+/**
+ * Append, re-allocating as needed.
+ *
+ * @param head - pointer to heap buffer head, may be updated on realloc.
+ * @param size - string size pointer, may be updated on realloc.
+ * @param appended - string to append
+ * @return false on alloc error
+ */
+bool append_realloc(char **head, size_t *cap, const char *appended);
+
+/**
+ * Test if a file descriptor is valid (e.g. when cleaning up after a failed select)
+ *
+ * @param fd - file descriptor number
+ * @return is valid
+ */
+bool fd_is_valid(int fd);
+
+/**
+ * parse user-provided string as boolean
+ *
+ * @param str
+ * @return is true
+ */
+bool parse_boolean_arg(const char *str);
+
+/**
+ * complementary function to parse_boolean_arg() that matches strings
+ * meaning 'false'. Can be used together with the positive version
+ * in case there can be other values as well.
+ *
+ * @param str
+ * @return is false
+ */
+bool parse_boolean_arg_false(const char *str);
+
+/** Check equality of two strings; returns bool */
+#define streq(a, b) (strcmp((const char*)(a), (const char*)(b)) == 0)
+
+/** Check prefix equality of two strings; returns bool */
+#define strneq(a, b, n) (strncmp((const char*)(a), (const char*)(b), (n)) == 0)
+
+/** Check if a string starts with a substring; returns bool */
+#define strstarts(a, b) strneq((a), (b), (int)strlen((b)))
+
+#ifndef MIN
+/** Get min of two numbers */
+#define MIN(a, b) ((a) > (b) ? (b) : (a))
+#endif
+
+#ifndef MAX
+/** Get max of two values */
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#endif
+
+#ifndef STR
+#define STR_HELPER(x) #x
+/** Stringify a token */
+#define STR(x) STR_HELPER(x)
+#endif
+
+#endif //COMMON_UTILS_UTILS_H

components/common_utils/src/base16.c

@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2010 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <esp_log.h>
+
+static const char *TAG = "base16";
+
+void base16_encode(uint8_t *raw, size_t len, char *encoded) {
+	uint8_t *raw_bytes = raw;
+	char *encoded_bytes = encoded;
+	size_t remaining = len;
+
+	for (; remaining--; encoded_bytes += 2)
+		snprintf(encoded_bytes, 3, "%02X", *(raw_bytes++));
+
+}
+
+int base16_decode(const char *encoded, uint8_t *raw) {
+	const char *encoded_bytes = encoded;
+	uint8_t *raw_bytes = raw;
+	char buf[3];
+	char *endp;
+	size_t len;
+
+	while (encoded_bytes[0]) {
+		if (!encoded_bytes[1]) {
+			ESP_LOGE(TAG, "Base16-encoded string \"%s\" has invalid length\n",
+					encoded);
+			return -22;
+		}
+		memcpy(buf, encoded_bytes, 2);
+		buf[2] = '\0';
+		*(raw_bytes++) = strtoul(buf, &endp, 16);
+		if (*endp != '\0') {
+			ESP_LOGE(TAG,"Base16-encoded string \"%s\" has invalid byte \"%s\"\n",
+					encoded, buf);
+			return -22;
+		}
+		encoded_bytes += 2;
+	}
+	len = (raw_bytes - raw);
+	return (len);
+}

components/common_utils/src/common_utils.c

@@ -0,0 +1,85 @@
+#include <stdint.h>
+#include <string.h>
+#include <stdbool.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <assert.h>
+
+#include "common_utils/utils.h"
+
+char *append(char *buf, const char *appended, size_t *pcap)
+{
+    char c;
+    char *buf0 = buf;
+    size_t cap = *pcap;
+
+    if (buf0 == NULL) return NULL;
+    if (appended == NULL || appended[0] == 0) return buf0;
+
+    if (*pcap < strlen(appended)+1) {
+        return NULL;
+    }
+
+    while (cap > 1 && 0 != (c = *appended++)) {
+        *buf++ = c;
+        cap--;
+    }
+    assert(cap > 0);
+
+    *pcap = cap;
+    *buf = 0;
+    return buf;
+}
+
+bool append_realloc(char **head, size_t *cap, const char *appended) {
+    if (!head) return NULL;
+    if (!*head) return NULL;
+    if (!cap) return NULL;
+    if (!appended) return NULL;
+
+    size_t cursize = strlen(*head);
+    size_t needed = strlen(appended) + 1;
+    size_t remains = *cap - cursize;
+
+    if (remains < needed) {
+        size_t need_extra = needed - remains;
+        size_t newsize = *cap + need_extra;
+        char *new = realloc(*head, newsize);
+        if (!new) return false;
+        *head = new;
+        *cap = newsize;
+    }
+
+    strcpy(*head + cursize, appended);
+    return true;
+}
+
+bool fd_is_valid(int fd)
+{
+    return fcntl(fd, F_GETFD) != -1 || errno != EBADF;
+}
+
+bool parse_boolean_arg(const char *str)
+{
+    if (0 == strcasecmp(str, "on")) return true;
+    if (0 == strcmp(str, "1")) return true;
+    if (0 == strcasecmp(str, "yes")) return true;
+    if (0 == strcasecmp(str, "enable")) return true;
+    if (0 == strcasecmp(str, "en")) return true;
+    if (0 == strcasecmp(str, "y")) return true;
+    if (0 == strcasecmp(str, "a")) return true;
+
+    return false;
+}
+
+bool parse_boolean_arg_false(const char *str)
+{
+    if (0 == strcasecmp(str, "off")) return true;
+    if (0 == strcmp(str, "0")) return true;
+    if (0 == strcasecmp(str, "no")) return true;
+    if (0 == strcasecmp(str, "disable")) return true;
+    if (0 == strcasecmp(str, "dis")) return true;
+    if (0 == strcasecmp(str, "n")) return true;
+
+    return false;
+}

components/common_utils/src/datetime.c

@@ -0,0 +1,110 @@
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include "common_utils/datetime.h"
+
+const char *DT_WKDAY_NAMES[] = {
+    [MONDAY] = "Mon",
+    [TUESDAY] = "Tue",
+    [WEDNESDAY] = "Wed",
+    [THURSDAY] = "Thu",
+    [FRIDAY] = "Fri",
+    [SATURDAY] = "Sat",
+    [SUNDAY] = "Sun"
+};
+
+const char *DT_WKDAY_NAMES_FULL[] = {
+    [MONDAY] = "Monday",
+    [TUESDAY] = "Tuesday",
+    [WEDNESDAY] = "Wednesday",
+    [THURSDAY] = "Thursday",
+    [FRIDAY] = "Friday",
+    [SATURDAY] = "Saturday",
+    [SUNDAY] = "Sunday"
+};
+
+const char *DT_MONTH_NAMES[] = {
+    [JANUARY] = "Jan",
+    [FEBRUARY] = "Feb",
+    [MARCH] = "Mar",
+    [APRIL] = "Apr",
+    [MAY] = "May",
+    [JUNE] = "Jun",
+    [JULY] = "Jul",
+    [AUGUST] = "Aug",
+    [SEPTEMBER] = "Sep",
+    [OCTOBER] = "Oct",
+    [NOVEMBER] = "Nov",
+    [DECEMBER] = "Dec"
+};
+
+const char *DT_MONTH_NAMES_FULL[] = {
+    [JANUARY] = "January",
+    [FEBRUARY] = "February",
+    [MARCH] = "March",
+    [APRIL] = "April",
+    [MAY] = "May",
+    [JUNE] = "June",
+    [JULY] = "July",
+    [AUGUST] = "August",
+    [SEPTEMBER] = "September",
+    [OCTOBER] = "October",
+    [NOVEMBER] = "November",
+    [DECEMBER] = "December"
+};
+
+static const uint16_t MONTH_LENGTHS[] = { /* 1-based, normal year */
+    [JANUARY]=31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+};
+_Static_assert(sizeof(MONTH_LENGTHS) / sizeof(uint16_t) == 13, "Months array length");
+
+static const uint16_t MONTH_YEARDAYS[] = { /* 1-based */
+    [JANUARY]=0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 // // days until 1st of month
+};
+_Static_assert(sizeof(MONTH_YEARDAYS) / sizeof(uint16_t) == 13, "Months array length");
+
+_Static_assert(MONDAY < SUNDAY, "Weekday ordering");
+
+bool datetime_is_valid(const datetime_t *dt)
+{
+    if (dt == NULL) return false;
+
+    // check month first to avoid out-of-bounds read from the MONTH_LENGTHS table
+    if (!(dt->month >= JANUARY && dt->month <= DECEMBER)) return false;
+
+    int monthlen = MONTH_LENGTHS[dt->month];
+    if (dt->month == FEBRUARY && is_leap_year(dt->year)) {
+        monthlen = 29;
+    }
+
+    return dt->sec < 60 &&
+           dt->min < 60 &&
+           dt->hour < 24 &&
+           dt->wkday >= MONDAY &&
+           dt->wkday <= SUNDAY &&
+           dt->year >= DT_START_YEAR &&
+           dt->year <= DT_END_YEAR &&
+           dt->day >= 1 &&
+           dt->day <= monthlen;
+}
+
+bool datetime_set_weekday(datetime_t *dt)
+{
+    dt->wkday = MONDAY; // prevent the validator func erroring out on invalid weekday
+    if (!datetime_is_valid(dt)) return false;
+    dt->wkday = date_weekday(dt->year, dt->month, dt->day);
+    return true;
+}
+
+enum weekday date_weekday(uint16_t year, enum month month, uint8_t day)
+{
+    uint16_t days = (DT_START_WKDAY - MONDAY) + (year - DT_START_YEAR) * 365 + MONTH_YEARDAYS[month] + (day - 1);
+
+    for (uint16_t i = DT_START_YEAR; i <= year; i++) {
+        if (is_leap_year(i) && (i < year || month > FEBRUARY)) days++;
+    }
+
+    return MONDAY + days % 7;
+}
+

components/common_utils/src/hexdump.c

@@ -0,0 +1,72 @@
+/*
+ * util.c
+ *
+ *  Created on: Aug 12, 2009
+ *      Author: johan
+ */
+
+// adapted from libgomspace
+
+#include <string.h>
+#include <stdio.h>
+#include "common_utils/hexdump.h"
+
+
+//! Dump memory to debugging output
+/**
+ * Dumps a chunk of memory to the screen
+ */
+void hex_dump(FILE * fp, void *src, int len) {
+	int i, j=0, k;
+	char text[17];
+
+	text[16] = '\0';
+	//printf("Hex dump:\r\n");
+	fprintf(fp, "%p : ", src);
+	for(i=0; i<len; i++) {
+		j++;
+		fprintf(fp, "%02X ", ((volatile unsigned char *)src)[i]);
+		if(j == 8)
+			fputc(' ', fp);
+		if(j == 16) {
+			j = 0;
+			memcpy(text, &((char *)src)[i-15], 16);
+			for(k=0; k<16; k++) {
+				if((text[k] < 32) || (text[k] > 126)) {
+					text[k] = '.';
+				}
+			}
+			fprintf(fp, " |%s|\n\r", text);
+			if(i<len-1) {
+				fprintf(fp, "%p : ", src+i+1);
+			}
+		}
+	}
+	if (i % 16)
+		fprintf(fp, "\r\n");
+}
+
+void hex_dump_buff_line(FILE *fp, int addr_size, unsigned pos, char *line, unsigned len)
+{
+  unsigned i;
+
+  fprintf(fp, "%0*x", addr_size, pos);
+  for (i = 0; i < HEX_DUMP_LINE_BUFF_SIZ; i++)
+  {
+    if (!(i % 8))
+      fputc(' ', fp);
+    if (i < len)
+      fprintf(fp, " %02x", (unsigned char)line[i]);
+    else
+	  fputs("   ", fp);
+  }
+  fputs("  |", fp);
+  for (i = 0; i < HEX_DUMP_LINE_BUFF_SIZ && i < len; i++)
+  {
+    if (line[i] >= 32 && line[i] <= 126)
+      fprintf(fp, "%c", (unsigned char)line[i]);
+    else
+		fputc('.', fp);
+  }
+  fputs("|\r\n", fp);
+}

components/fileserver/CMakeLists.txt

@@ -0,0 +1,9 @@
+set(COMPONENT_ADD_INCLUDEDIRS
+        "include")
+
+set(COMPONENT_SRCDIRS
+        "src")
+
+set(COMPONENT_REQUIRES tcpip_adapter esp_http_server httpd_utils common_utils)
+
+register_component()

components/fileserver/README.txt

@@ -0,0 +1,2 @@
+File and template serving support for the http_server bundled with ESP-IDF.
+

components/fileserver/component.mk

@@ -0,0 +1,3 @@
+
+COMPONENT_SRCDIRS := src
+COMPONENT_ADD_INCLUDEDIRS := include

components/fileserver/include/fileserver/embedded_files.h

@@ -0,0 +1,51 @@
+//
+// Created on 2018/10/17 by Ondrej Hruska <ondra@ondrovo.com>
+//
+
+#ifndef FBNODE_EMBEDDED_FILES_H
+#define FBNODE_EMBEDDED_FILES_H
+
+#include <stdint.h>
+#include <esp_err.h>
+#include <stdbool.h>
+
+struct embedded_file_info {
+    const uint8_t * start;
+    const uint8_t * end;
+    const char * name;
+    const char * mime;
+};
+
+enum file_access_level {
+    /** Public = file accessed by a wildcard route */
+    FILE_ACCESS_PUBLIC = 0,
+    /** Protected = file included in a template or explicitly specified in a route */
+    FILE_ACCESS_PROTECTED = 1,
+    /** Files protected against read-out */
+    FILE_ACCESS_PRIVATE = 2,
+};
+
+extern const struct embedded_file_info EMBEDDED_FILE_LOOKUP[];
+extern const size_t EMBEDDED_FILE_LOOKUP_LEN;
+
+/**
+ * Find an embedded file by its name.
+ * 
+ * This function is weak. It crawls the EMBEDDED_FILE_LOOKUP table and checks for exact match, also
+ * testing with www_get_static_file_access_check if the access is allowed.
+ *
+ * @param name - file name
+ * @param access - access level (public - wildcard fallthrough, protected - files for the server, loaded explicitly)
+ * @param[out] file - the file struct is stored here if found, unchanged if not found.
+ * @return status code
+ */
+esp_err_t www_get_static_file(const char *name, enum file_access_level access, const struct embedded_file_info **file);
+
+/**
+ * Check file access permission (if using the default www_get_static_file implementation).
+ * 
+ * This function is weak. The default implementation returns always true.
+ */
+bool www_get_static_file_access_check(const struct embedded_file_info *file, enum file_access_level access);
+
+#endif //FBNODE_EMBEDDED_FILES_H

components/fileserver/include/fileserver/token_subs.h

@@ -0,0 +1,227 @@
+//
+// This module implements token substitution in files served by the server.
+//
+// Tokens are in the form {token}, or {escape:token}, where escape can be:
+// - h ... html escape (plain text in a html file, attribute value)
+// - j ... js escape (for use in JS strings)
+//
+// When no escape is specified, the token substitution is written verbatim into the response.
+//
+//   var foo = "{j:foo}";
+//   <input value="{h:old_value}">
+//   {generated-html-goes-here}
+//
+// Token can be made optional by adding '?' at the end (this can't be used for includes).
+// Such token then simply becomes empty string when not substituted, as opposed to being included in the page verbatim.
+//
+//   <input value="{h:old_value?}">
+//
+// token names can contain alnum, dash, period and underscore, and are case sensitive.
+//
+//
+// It is further possible to include a static file with optional key-value replacements. These serve as defaults.
+//
+//   {@_subfile.html}
+//   {@_subfile.html|key=value lalala}
+//   {@_subfile.html|key=value lalala|other=value}
+//
+// File inclusion can be nested, and the files can use replacement tokens as specified by the include statement
+//
+// Created on 2019/01/24 by Ondrej Hruska <ondra@ondrovo.com>
+//
+
+#ifndef FBNODE_TOKEN_SUBS_H
+#define FBNODE_TOKEN_SUBS_H
+
+#include "embedded_files.h"
+#include <rom/queue.h>
+#include <esp_err.h>
+#include <esp_http_server.h>
+
+/** Max length of a token buffer (must suffice for all included filenames) */
+#define MAX_TOKEN_LEN 32
+
+/** Max length of a key-value substitution when using tpl_kv_replacer;
+ * This is also used internally for in-line replacements in file imports. */
+#define TPL_KV_KEY_LEN 24
+/** Max length of a substituion in tpl_kv_replacer */
+#define TPL_KV_SUBST_LEN 64
+
+/**
+ * Escape type - argument for httpd_resp_send_chunk_escaped()
+ */
+typedef enum {
+    TPL_ESCAPE_NONE = 0,
+    TPL_ESCAPE_HTML,
+    TPL_ESCAPE_JS,
+} tpl_escape_t;
+
+enum {
+    HTOPT_NONE = 0,
+    HTOPT_NO_HEADERS = 1 << 0,
+    HTOPT_NO_CLOSE = 1 << 1,
+    HTOPT_INCLUDE = HTOPT_NO_HEADERS|HTOPT_NO_CLOSE,
+};
+
+/**
+ * Send string using a given escaping scheme
+ *
+ * @param r
+ * @param buf - buf to send
+ * @param len - buf len, or HTTPD_RESP_USE_STRLEN
+ * @param escape - escaping type
+ * @return success
+ */
+esp_err_t httpd_resp_send_chunk_escaped(httpd_req_t *r, const char *buf, ssize_t len, tpl_escape_t escape);
+
+/**
+ * Template substitution callback. Data shall be sent using httpd_resp_send_chunk_escaped().
+ *
+ * @param[in,out] context - user-defined page state data
+ * @param[in] token - replacement token
+ * @return ESP_OK if the token was substituted, ESP_ERR_NOT_FOUND if it is unknown, other errors on e.g. send failure
+ */
+typedef esp_err_t (*template_subst_t)(httpd_req_t *r, void *context, const char *token, tpl_escape_t escape);
+
+/**
+ * Send a template file as a response. The content type from the file struct will be used.
+ *
+ * Use HTOPT_INCLUDE when used to embed a file inside a template.
+ *
+ * @param r - request
+ * @param file_index - file index in EMBEDDED_FILE_LOOKUP
+ * @param replacer - substitution callback, can be NULL if only includes are to be processed
+ * @param context - arbitrary context, will be passed to the replacer function; can be NULL
+ * @param opts - flag options (HTOPT_*)
+ */
+esp_err_t httpd_send_template_file(httpd_req_t *r, int file_index, template_subst_t replacer, void *context, uint32_t opts);
+
+/**
+ * Same as httpd_send_template_file, but using an `embedded_file_info` struct.
+ */
+esp_err_t httpd_send_template_file_struct(httpd_req_t *r, const struct embedded_file_info *file, template_subst_t replacer, void *context, uint32_t opts);
+
+/**
+ * Process and send a string template.
+ * The content-type header should be set beforehand, if different from the default (text/html).
+ *
+ * Use HTOPT_INCLUDE when used to embed a file inside a template.
+ *
+ * @param r - request
+ * @param template - template string (does not have to be terminated by a null byte)
+ * @param template_len - length of the template string; -1 to use strlen()
+ * @param replacer - substitution callback, can be NULL if only includes are to be processed
+ * @param context - arbitrary context, will be passed to the replacer function; can be NULL
+ * @param opts - flag options (HTOPT_*)
+ */
+esp_err_t httpd_send_template(httpd_req_t *r, const char *template, ssize_t template_len, template_subst_t replacer, void *context, uint32_t opts);
+
+/**
+ * Send a static file. This can be used to just send a file, or to embed a static template as a token substitution.
+ *
+ * Use HTOPT_INCLUDE when used to embed a file inside a template.
+ *
+ * Note: use httpd_resp_send_chunk_escaped() or httpd_resp_send_chunk() to send a plain string.
+ *
+ * @param r - request
+ * @param file_index - file index in EMBEDDED_FILE_LOOKUP
+ * @param escape - escape option
+ * @param opts - flag options (HTOPT_*)
+ * @return
+ */
+esp_err_t httpd_send_static_file(httpd_req_t *r, int file_index, tpl_escape_t escape, uint32_t opts);
+
+/**
+ * Same as httpd_send_template_file, but using an `embedded_file_info` struct.
+ */
+esp_err_t httpd_send_static_file_struct(httpd_req_t *r, const struct embedded_file_info *file, tpl_escape_t escape, uint32_t opts);
+
+struct tpl_kv_entry {
+    char key[TPL_KV_KEY_LEN]; // copied here
+    char subst[TPL_KV_SUBST_LEN]; // copied here
+    char *subst_heap;
+    SLIST_ENTRY(tpl_kv_entry) link;
+};
+
+SLIST_HEAD(tpl_kv_list, tpl_kv_entry);
+
+/**
+ * key-value replacer that works with a dynamically allocated SLIST.
+ *
+ * @param r - request
+ * @param context - context - must be a pointer to `struct tpl_kv_list`
+ * @param token - token to replace
+ * @param escape - escape option
+ * @return OK/not found/other
+ */
+esp_err_t tpl_kv_replacer(httpd_req_t *r, void *context, const char *token, tpl_escape_t escape);
+
+/**
+ * Add a pair into the substitutions list
+ *
+ * @param head - list head
+ * @param key - key, copied
+ * @param subst - value, copied
+ * @return success (fails if malloc failed)
+ */
+esp_err_t tpl_kv_add(struct tpl_kv_list *head, const char *key, const char *subst);
+
+/**
+ * Add a heap-allocated string to the replacer.
+ *
+ * @param head - list head
+ * @param key - key, copied
+ * @param subst - value, copied
+ * @return success (fails if malloc failed)
+ */
+esp_err_t tpl_kv_add_heapstr(struct tpl_kv_list *head, const char *key, char *subst);
+
+/**
+ * Convenience function that converts an IP address to string and adds it as a substitution
+ *
+ * @param head - list head
+ * @param key - key, copied
+ * @param ip4h - host order ipv4 address
+ * @return success
+ */
+esp_err_t tpl_kv_add_ipv4str(struct tpl_kv_list *head, const char *key, uint32_t ip4h);
+
+/** add int as a substitution; key is copied */
+esp_err_t tpl_kv_add_int(struct tpl_kv_list *head, const char *key, int32_t num);
+
+/** add long as a substitution; key is copied */
+esp_err_t tpl_kv_add_long(struct tpl_kv_list *head, const char *key, int64_t num);
+
+/** add printf-formatted value; key is copied */
+esp_err_t tpl_kv_sprintf(struct tpl_kv_list *head, const char *key, const char *format, ...)
+    __attribute__((format(printf,3,4)));
+
+/**
+ * Init a substitutions list (on the stack)
+ *
+ * @return the list
+ */
+static inline struct tpl_kv_list tpl_kv_init(void)
+{
+    return (struct tpl_kv_list) {.slh_first = NULL};
+}
+
+/**
+ * Free the list (head is left alone because it was allocated on the stack)
+ * @param head
+ */
+void tpl_kv_free(struct tpl_kv_list *head);
+
+/**
+ * Send the map as an ASCII table separated by Record Separator (30) and Unit Separator (31).
+ * Content type is set to application/octet-stream.
+ *
+ * key 31 value 30
+ * key 31 value 30
+ * key 31 value
+ *
+ * @param req
+ */
+esp_err_t tpl_kv_send_as_ascii_map(httpd_req_t *req, struct tpl_kv_list *head);
+
+#endif //FBNODE_TOKEN_SUBS_H

components/fileserver/readme/README.md

@@ -0,0 +1,29 @@
+Place the `rebuild_file_tables.php` script in a `files` subfolder of the main component.
+It requires PHP 7 to run. 
+
+This is what the setup should look like
+
+```
+main/files/embed/index.html
+main/files/rebuild_file_tables.php
+main/CMakeLists.txt
+main/main.c
+```
+
+Add this to your CMakeLists.txt before `register_component`:
+
+```
+#begin staticfiles
+#end staticfiles
+```
+
+The script will update CMakeLists.txt and generate `files_enum.c` and `files_enum.h` when run.
+
+```
+main/files/files_enum.h
+main/files/files_enum.c
+```
+
+Ensure `files/files_enum.c` is included in the build.
+
+`www_get_static_file()` is implemented as weak to let you provide custom access authentication logic.

components/fileserver/readme/rebuild_file_tables.php

@@ -0,0 +1,170 @@
+#!/usr/bin/env php
+<?php
+// This script rebuilds the static files enum, extern symbols pointing to the embedded byte buffers,
+// and the look-up structs table. To add more files, simply add them in the 'files' directory.
+
+// Note that all files will be accessible by the webserver, unless you filter them in embedded_files.c.
+
+
+// List all files
+$files = scandir(__DIR__.'/embed');
+
+$files = array_filter(array_map(function ($f) {
+  if (!is_file(__DIR__.'/embed/'.$f)) return null;
+  if (preg_match('/^\.|\.kate-swp|\.bak$|~$|\.sh$/', $f)) return null;
+
+  echo "Found: $f\n";
+  return $f;
+}, $files));
+
+sort($files);
+
+$formatted = array_filter(array_map(function ($f) {
+  return "\"files/embed/$f\"";
+}, $files));
+
+$cmake = file_get_contents(__DIR__.'/../CMakeLists.txt');
+
+$cmake = preg_replace('/#begin staticfiles\n.*#end staticfiles/s', 
+  "#begin staticfiles\n".
+  "set(COMPONENT_EMBED_FILES\n        ".
+  implode("\n        ", $formatted) . ")\n".
+  "#end staticfiles", 
+  $cmake);
+
+file_put_contents(__DIR__.'/../CMakeLists.txt', $cmake);
+
+
+// Generate a list of files
+
+$num = 0;
+$enum_keys = array_map(function ($f) use(&$num) {
+  $a = preg_replace("/[^A-Z0-9_]+/", "_", strtoupper($f));
+  return 'FILE_'. $a.' = '.($num++);
+}, $files);
+
+$keylist = implode(",\n    ", $enum_keys);
+
+$struct_array = [];
+
+$externs = array_map(function ($f) use (&$struct_array) {
+  $a = preg_replace("/[^A-Z0-9_]+/", "_", strtoupper($f));
+  
+  $start = '_binary_'. strtolower($a).'_start';
+  $end = '_binary_'. strtolower($a).'_end';
+  
+  static $mimes = array(
+    'txt' => 'text/plain',
+    'htm' => 'text/html',
+    'html' => 'text/html',
+    'php' => 'text/html',
+    'css' => 'text/css',
+    'js' => 'application/javascript',
+    'json' => 'application/json',
+    'xml' => 'application/xml',
+    'swf' => 'application/x-shockwave-flash',
+    'flv' => 'video/x-flv',
+    
+    'pem' => 'application/x-pem-file',
+
+    // images
+    'png' => 'image/png',
+    'jpe' => 'image/jpeg',
+    'jpeg' => 'image/jpeg',
+    'jpg' => 'image/jpeg',
+    'gif' => 'image/gif',
+    'bmp' => 'image/bmp',
+    'ico' => 'image/vnd.microsoft.icon',
+    'tiff' => 'image/tiff',
+    'tif' => 'image/tiff',
+    'svg' => 'image/svg+xml',
+    'svgz' => 'image/svg+xml',
+
+    // archives
+    'zip' => 'application/zip',
+    'rar' => 'application/x-rar-compressed',
+    'exe' => 'application/x-msdownload',
+    'msi' => 'application/x-msdownload',
+    'cab' => 'application/vnd.ms-cab-compressed',
+
+    // audio/video
+    'mp3' => 'audio/mpeg',
+    'qt' => 'video/quicktime',
+    'mov' => 'video/quicktime',
+
+    // adobe
+    'pdf' => 'application/pdf',
+    'psd' => 'image/vnd.adobe.photoshop',
+    'ai' => 'application/postscript',
+    'eps' => 'application/postscript',
+    'ps' => 'application/postscript',
+
+    // ms office
+    'doc' => 'application/msword',
+    'rtf' => 'application/rtf',
+    'xls' => 'application/vnd.ms-excel',
+    'ppt' => 'application/vnd.ms-powerpoint',
+
+    // open office
+    'odt' => 'application/vnd.oasis.opendocument.text',
+    'ods' => 'application/vnd.oasis.opendocument.spreadsheet',
+  );
+  
+  $parts = explode('.', $f);
+  $suffix = end($parts);
+  $mime = $mimes[$suffix] ?? 'application/octet-stream';
+  
+  $len = filesize('embed/'.$f);
+  
+  $struct_array[] = "[FILE_$a] = {{$start}, {$end}, \"{$f}\", \"{$mime}\"},";
+  
+  return 
+    'extern const uint8_t '.$start.'[];'."\n".
+    'extern const uint8_t '.$end.'[];';
+}, $files);
+
+$externlist = implode("\n", $externs);
+$structlist = implode("\n    ", $struct_array);
+
+
+file_put_contents('files_enum.h', <<<FILE
+// Do not change, auto-generated by gen_staticfiles.php
+
+#ifndef _EMBEDDED_FILES_ENUM_H
+#define _EMBEDDED_FILES_ENUM_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+enum embedded_file_id {
+    $keylist,
+    FILE_MAX
+};
+
+struct embedded_file_info {
+  const uint8_t * start;
+  const uint8_t * end;
+  const char * name;
+  const char * mime;
+};
+
+$externlist
+
+extern const struct embedded_file_info EMBEDDED_FILE_LOOKUP[];
+
+#endif // _EMBEDDED_FILES_ENUM_H
+
+FILE
+);
+
+file_put_contents("files_enum.c", <<<FILE
+// Do not change, auto-generated by gen_staticfiles.php
+#include <stdint.h>
+#include "files_enum.h"
+
+const struct embedded_file_info EMBEDDED_FILE_LOOKUP[] = {
+    $structlist
+};
+
+FILE
+);

components/fileserver/src/embedded_files.c

@@ -0,0 +1,22 @@
+#include <esp_err.h>
+#include "fileserver/embedded_files.h"
+#include "string.h"
+
+esp_err_t __attribute__((weak)) 
+www_get_static_file(const char *name, enum file_access_level access, const struct embedded_file_info **file)
+{
+    // simple search by name
+    for(int i = 0; i < EMBEDDED_FILE_LOOKUP_LEN; i++) {
+        if (0 == strcmp(EMBEDDED_FILE_LOOKUP[i].name, name)) {
+            *file = &EMBEDDED_FILE_LOOKUP[i];
+            return ESP_OK;
+        }
+    }
+
+    return ESP_ERR_NOT_FOUND;
+}
+
+bool __attribute__((weak)) 
+www_get_static_file_access_check(const struct embedded_file_info *file, enum file_access_level access) {
+  return true;
+}

components/fileserver/src/token_subs.c

@@ -0,0 +1,619 @@
+//#define LOG_LOCAL_LEVEL ESP_LOG_DEBUG
+
+#include <esp_log.h>
+#include <esp_http_server.h>
+#include <rom/queue.h>
+#include <lwip/ip4_addr.h>
+#include <sys/param.h>
+#include <common_utils/utils.h>
+#include <fileserver/token_subs.h>
+
+#include "fileserver/embedded_files.h"
+#include "fileserver/token_subs.h"
+
+#define ESP_TRY(x) \
+    do {  \
+        esp_err_t try_er = (x);  \
+        if (try_er != ESP_OK) return try_er;  \
+    } while(0)
+
+static const char* TAG = "token_subs";
+
+// TODO implement buffering to avoid sending many tiny chunks when escaping
+
+/* encode for HTML. returns 0 or 1 - 1 = success */
+static esp_err_t send_html_chunk(httpd_req_t *r, const char *data, ssize_t len)
+{
+    assert(r);
+    assert(data);
+
+    int start = 0, end = 0;
+    char c;
+    if (len < 0) len = (int) strlen(data);
+    if (len==0) return ESP_OK;
+
+    for (end = 0; end < len; end++) {
+        c = data[end];
+        if (c == 0) {
+            // we found EOS
+            break; // not return - the last chunk is printed after the loop
+        }
+
+        if (c == '"' || c == '\'' || c == '<' || c == '>') {
+            if (start < end) ESP_TRY(httpd_resp_send_chunk(r, data + start, end - start));
+            start = end + 1;
+        }
+
+        if (c == '"') ESP_TRY(httpd_resp_send_chunk(r, "&#34;", 5));
+        else if (c == '\'') ESP_TRY(httpd_resp_send_chunk(r, "&#39;", 5));
+        else if (c == '<') ESP_TRY(httpd_resp_send_chunk(r, "&lt;", 4));
+        else if (c == '>') ESP_TRY(httpd_resp_send_chunk(r, "&gt;", 4));
+    }
+
+    if (start < end) ESP_TRY(httpd_resp_send_chunk(r, data + start, end - start));
+    return ESP_OK;
+}
+
+/* encode for JS. returns 0 or 1 - 1 = success */
+static esp_err_t send_js_chunk(httpd_req_t *r, const char *data, ssize_t len)
+{
+    assert(r);
+    assert(data);
+
+    int start = 0, end = 0;
+    char c;
+    if (len < 0) len = (int) strlen(data);
+    if (len==0) return ESP_OK;
+
+    for (end = 0; end < len; end++) {
+        c = data[end];
+        if (c == 0) {
+            // we found EOS
+            break; // not return - the last chunk is printed after the loop
+        }
+
+        if (c == '"' || c == '\\' || c == '/' || c == '\'' || c == '<' || c == '>' || c == '\n' || c == '\r') {
+            if (start < end) ESP_TRY(httpd_resp_send_chunk(r, data + start, end - start));
+            start = end + 1;
+        }
+
+        if (c == '"') ESP_TRY(httpd_resp_send_chunk(r, "\\\"", 2));
+        else if (c == '\'') ESP_TRY(httpd_resp_send_chunk(r, "\\'", 2));
+        else if (c == '\\') ESP_TRY(httpd_resp_send_chunk(r, "\\\\", 2));
+        else if (c == '/') ESP_TRY(httpd_resp_send_chunk(r, "\\/", 2));
+        else if (c == '<') ESP_TRY(httpd_resp_send_chunk(r, "\\u003C", 6));
+        else if (c == '>') ESP_TRY(httpd_resp_send_chunk(r, "\\u003E", 6));
+        else if (c == '\n') ESP_TRY(httpd_resp_send_chunk(r, "\\n", 2));
+        else if (c == '\r') ESP_TRY(httpd_resp_send_chunk(r, "\\r", 2));
+    }
+
+    if (start < end) ESP_TRY(httpd_resp_send_chunk(r, data + start, end - start));
+    return ESP_OK;
+}
+
+
+esp_err_t httpd_resp_send_chunk_escaped(httpd_req_t *r, const char *buf, ssize_t len, tpl_escape_t escape)
+{
+    switch (escape) {
+        default: // this enum should be exhaustive, but in case something went wrong, just print it verbatim
+
+        case TPL_ESCAPE_NONE:
+            return httpd_resp_send_chunk(r, buf, len);
+
+        case TPL_ESCAPE_HTML:
+            return send_html_chunk(r, buf, len);
+
+        case TPL_ESCAPE_JS:
+            return send_js_chunk(r, buf, len);
+    }
+}
+
+esp_err_t httpd_send_static_file(httpd_req_t *r, int file_index, tpl_escape_t escape, uint32_t opts)
+{
+    assert(file_index < EMBEDDED_FILE_LOOKUP_LEN);
+    const struct embedded_file_info *file = &EMBEDDED_FILE_LOOKUP[file_index];
+
+    return httpd_send_static_file_struct(r, file, escape, opts);
+}
+
+esp_err_t httpd_send_static_file_struct(httpd_req_t *r, const struct embedded_file_info *file, tpl_escape_t escape, uint32_t opts)
+{
+    if (0 == (opts & HTOPT_NO_HEADERS)) {
+        ESP_TRY(httpd_resp_set_type(r, file->mime));
+        ESP_TRY(httpd_resp_set_hdr(r, "Cache-Control", "max-age=86400, public, must-revalidate"));
+    }
+
+    ESP_TRY(httpd_resp_send_chunk_escaped(r, (const char *) file->start, (size_t)(file->end - file->start), escape));
+
+    if (0 == (opts & HTOPT_NO_CLOSE)) {
+        ESP_TRY(httpd_resp_send_chunk(r, NULL, 0));
+    }
+
+    return ESP_OK;
+}
+
+esp_err_t httpd_send_template_file(httpd_req_t *r,
+                                   int file_index,
+                                   template_subst_t replacer,
+                                   void *context,
+                                   uint32_t opts)
+{
+    assert(file_index < EMBEDDED_FILE_LOOKUP_LEN);
+    const struct embedded_file_info *file = &EMBEDDED_FILE_LOOKUP[file_index];
+    return httpd_send_template_file_struct(r,file,replacer,context,opts);
+}
+
+esp_err_t httpd_send_template_file_struct(httpd_req_t *r,
+                                   const struct embedded_file_info *file,
+                                   template_subst_t replacer,
+                                   void *context,
+                                   uint32_t opts)
+{
+    if (0 == (opts & HTOPT_NO_HEADERS)) {
+        ESP_TRY(httpd_resp_set_type(r, file->mime));
+        ESP_TRY(httpd_resp_set_hdr(r, "Cache-Control", "no-cache, no-store, must-revalidate"));
+    }
+
+    return httpd_send_template(r, (const char *) file->start, (size_t)(file->end - file->start), replacer, context, opts);
+}
+
+esp_err_t tpl_kv_replacer(httpd_req_t *r, void *context, const char *token, tpl_escape_t escape)
+{
+    assert(context);
+    assert(token);
+
+    struct tpl_kv_entry *entry;
+    struct tpl_kv_list *head = context;
+    SLIST_FOREACH(entry, head, link) {
+        if (0==strcmp(entry->key, token)) {
+            return httpd_resp_send_chunk_escaped(r,
+                entry->subst_heap ?
+                    entry->subst_heap :
+                    entry->subst,
+                -1, escape);
+        }
+    }
+
+    return ESP_ERR_NOT_FOUND;
+}
+
+struct stacked_replacer_context {
+    template_subst_t replacer0;
+    void *context0;
+    template_subst_t replacer1;
+    void *context1;
+};
+
+esp_err_t stacked_replacer(httpd_req_t *r, void *context, const char *token, tpl_escape_t escape)
+{
+    assert(context);
+    assert(token);
+
+    struct stacked_replacer_context *combo = context;
+
+    if (ESP_OK == combo->replacer0(r, combo->context0, token, escape)) {
+        return ESP_OK;
+    }
+
+    if (ESP_OK == combo->replacer1(r, combo->context1, token, escape)) {
+        return ESP_OK;
+    }
+
+    return ESP_ERR_NOT_FOUND;
+}
+
+esp_err_t httpd_send_template(httpd_req_t *r,
+                              const char *template, ssize_t template_len,
+                              template_subst_t replacer,
+                              void *context,
+                              uint32_t opts)
+{
+    if (template_len < 0) template_len = strlen(template);
+
+    // replacer and context may be NULL
+    assert(template);
+    assert(r);
+
+    // data end
+    const char * const end = template + template_len;
+
+    // start of to-be-processed data
+    const char * pos = template;
+
+    // start position for finding opening braces, updated after a failed match to avoid infinite loop on the same bad token
+    const char * searchpos = pos;
+
+    // tokens must be copied to a buffer to allow adding the terminating null byte
+    char token_buf[MAX_TOKEN_LEN];
+
+    while (pos < end) {
+        const char * openbr = strchr(searchpos, '{');
+        if (openbr == NULL) {
+            // no more templates
+            ESP_TRY(httpd_resp_send_chunk(r, pos, (size_t) (end - pos)));
+            break;
+        }
+
+        // this brace could start a valid template. check if it seems valid...
+        const char * closebr = strchr(openbr, '}');
+        if (closebr == NULL) {
+            // there are no further closing braces, so it can't be a template
+
+            // we also know there can't be any more substitutions, because they would lack a closing } too
+            ESP_TRY(httpd_resp_send_chunk(r, pos, (size_t) (end - pos)));
+            break;
+        }
+
+        // see if the braces content looks like a token
+        const char *t = openbr + 1;
+        bool token_valid = true;
+        struct tpl_kv_list substitutions_head = tpl_kv_init();
+        struct tpl_kv_entry *new_subst_pair = NULL;
+
+        // a token can be either a name for replacement by the replacer func, or an include with static kv replacements
+        bool is_include = false;
+        bool token_is_optional = false;
+        const char *token_end = NULL; // points one char after the end of the token
+
+        // parsing the token
+        {
+            if (*t == '@') {
+                ESP_LOGD(TAG, "Parsing an Include token");
+                is_include = true;
+                t++;
+            }
+
+            enum {
+                P_NAME, P_KEY, P_VALUE
+            } state = P_NAME;
+
+            const char *kv_start = NULL;
+            while (t != closebr || state == P_VALUE) {
+                char c = *t;
+
+                if (state == P_NAME) {
+                    if (!((c >= 'a' && c <= 'z') ||
+                          (c >= 'A' && c <= 'Z') ||
+                          (c >= '0' && c <= '9') ||
+                          c == '.' || c == '_' || c == '-' || c == ':')) {
+
+                        if (!is_include && c == '?') {
+                            token_end = t;
+                            token_is_optional = true;
+                        } else {
+                            if (is_include && c == '|') {
+                                token_end = t;
+                                state = P_KEY;
+                                kv_start = t + 1;
+                                // pipe separates the include's filename and literal substitutions
+                                // we know there is a closing } somewhere, and {@....| doesn't occur normally, so let's assume it's correct
+                            }
+                            else {
+                                token_valid = false;
+                                break;
+                            }
+                        }
+                    }
+                }
+                else if (state == P_KEY) {
+                    if (!((c >= 'a' && c <= 'z') ||
+                          (c >= 'A' && c <= 'Z') ||
+                          (c >= '0' && c <= '9') ||
+                          c == '.' || c == '_' || c == '-')) {
+                        if (c == '=') {
+                            new_subst_pair = calloc(1, sizeof(struct tpl_kv_entry));
+                            const size_t klen = MIN(TPL_KV_KEY_LEN, t - kv_start);
+                            strncpy(new_subst_pair->key, kv_start, klen);
+                            new_subst_pair->key[klen] = 0;
+
+                            kv_start = t + 1;
+
+                            state = P_VALUE;
+                            // pipe separates the include's filename and literal substitutions
+                            // we know there is a closing } somewhere, and {@....| doesn't occur normally, so let's assume it's correct
+                        }
+                    }
+                }
+                else if (state == P_VALUE) {
+                    if (c == '|' || c == '}') {
+                        const size_t vlen = MIN(TPL_KV_SUBST_LEN, t - kv_start);
+                        strncpy(new_subst_pair->subst, kv_start, vlen);
+                        new_subst_pair->subst[vlen] = 0;
+
+                        // attach the kv pair to the list
+                        SLIST_INSERT_HEAD(&substitutions_head, new_subst_pair, link);
+                        ESP_LOGD(TAG, "Adding subs kv %s -> %s", new_subst_pair->key, new_subst_pair->subst);
+                        new_subst_pair = NULL;
+
+                        kv_start = t + 1; // go past the pipe
+                        state = P_KEY;
+
+                        if (t == closebr) {
+                            break; // found the ending brace, so let's quit the kv parse loop
+                        }
+                    }
+                }
+
+                t++;
+            }
+            // clean up after a messed up subs kv pairs syntax
+            if (new_subst_pair != NULL) {
+                free(new_subst_pair);
+            }
+        }
+
+        if (!token_valid) {
+            // false match, include it in the block to send before the next token
+            searchpos = openbr + 1;
+            ESP_LOGD(TAG, "Skip invalid token near %10s", openbr);
+            continue;
+        }
+
+        // now we know it looks like a substitution token
+
+        // flush data before the token
+        if (pos != openbr) ESP_TRY(httpd_resp_send_chunk(r, pos, (size_t) (openbr - pos)));
+
+        const char *token_start = openbr;
+
+        tpl_escape_t escape = TPL_ESCAPE_NONE;
+
+        // extract and terminate the token
+        size_t token_len = MIN(MAX_TOKEN_LEN-1, closebr - openbr - 1);
+        if (token_end) {
+            token_len = MIN(token_len, token_end - openbr - 1);
+        }
+
+        if (is_include) {
+            token_start += 1; // skip the @
+            token_len -= 1;
+        } else {
+            if (0 == strncmp("h:", openbr + 1, 2)) {
+                escape = TPL_ESCAPE_HTML;
+                token_start += 2;
+                token_len -= 2;
+            }
+            else if (0 == strncmp("j:", openbr + 1, 2)) {
+                escape = TPL_ESCAPE_JS;
+                token_start += 2;
+                token_len -= 2;
+            }
+        }
+
+        strncpy(token_buf, token_start+1, token_len);
+        token_buf[token_len] = 0;
+
+        ESP_LOGD(TAG, "Token: %s", token_buf);
+
+        esp_err_t rv;
+
+        if (is_include) {
+            ESP_LOGD(TAG, "Trying to include a sub-file");
+
+            const struct embedded_file_info *file = NULL;
+            rv = www_get_static_file(token_buf, FILE_ACCESS_PROTECTED, &file);
+            if (rv != ESP_OK) {
+                ESP_LOGE(TAG, "Failed to statically include \"%s\" in a template - %s", token_buf, esp_err_to_name(rv));
+                // this will cause the token to be emitted verbatim
+            } else {
+                ESP_LOGD(TAG, "Descending...");
+
+                // combine the two replacers
+                struct stacked_replacer_context combo = {
+                    .replacer0 = replacer,
+                    .context0 = context,
+                    .replacer1 = tpl_kv_replacer,
+                    .context1 = &substitutions_head
+                };
+
+                rv = httpd_send_template_file_struct(r, file, stacked_replacer, &combo, HTOPT_INCLUDE);
+                ESP_LOGD(TAG, "...back in parent");
+            }
+
+            // tear down the list
+            tpl_kv_free(&substitutions_head);
+
+            if (rv != ESP_OK) {
+                // just send it verbatim...
+                ESP_TRY(httpd_resp_send_chunk(r, openbr, (size_t) (closebr - openbr + 1)));
+            }
+        } else {
+            if (replacer) {
+                ESP_LOGD(TAG, "Running replacer for \"%s\" with escape %d", token_buf, escape);
+                rv = replacer(r, context, token_buf, escape);
+
+                if (rv != ESP_OK) {
+                    if (rv == ESP_ERR_NOT_FOUND) {
+                        ESP_LOGD(TAG, "Token rejected");
+                        // optional token becomes empty string if not replaced
+                        if (!token_is_optional) {
+                            ESP_LOGD(TAG, "Not optional, keeping verbatim");
+                            // replacer rejected the token, keep it verbatim
+                            ESP_TRY(httpd_resp_send_chunk(r, openbr, (size_t) (closebr - openbr + 1)));
+                        }
+                    }
+                    else {
+                        ESP_LOGE(TAG, "Unexpected error from replacer func: 0x%02x - %s", rv, esp_err_to_name(rv));
+                        return rv;
+                    }
+                }
+            } else {
+                ESP_LOGD(TAG, "Not replacer");
+                // no replacer, only includes - used for 'static' files
+                if (!token_is_optional) {
+                    ESP_LOGD(TAG, "Token not optional, keeping verbatim");
+                    ESP_TRY(httpd_resp_send_chunk(r, openbr, (size_t) (closebr - openbr + 1)));
+                }
+            }
+        }
+
+        searchpos = pos = closebr + 1;
+    }
+
+    if (0 == (opts & HTOPT_NO_CLOSE)) {
+        ESP_TRY(httpd_resp_send_chunk(r, NULL, 0));
+    }
+
+    return ESP_OK;
+}
+
+
+esp_err_t tpl_kv_add_int(struct tpl_kv_list *head, const char *key, int32_t num)
+{
+    char buf[12];
+    itoa(num, buf, 10);
+    return tpl_kv_add(head, key, buf);
+}
+
+esp_err_t tpl_kv_add_long(struct tpl_kv_list *head, const char *key, int64_t num)
+{
+    char buf[21];
+    sprintf(buf, "%"PRIi64, num);
+    return tpl_kv_add(head, key, buf);
+}
+
+esp_err_t tpl_kv_add_ipv4str(struct tpl_kv_list *head, const char *key, uint32_t ip4h)
+{
+    char buf[IP4ADDR_STRLEN_MAX];
+    ip4_addr_t addr;
+    addr.addr = lwip_htonl(ip4h);
+    ip4addr_ntoa_r(&addr, buf, IP4ADDR_STRLEN_MAX);
+
+    return tpl_kv_add(head, key, buf);
+}
+
+esp_err_t tpl_kv_add(struct tpl_kv_list *head, const char *key, const char *subst)
+{
+    ESP_LOGD(TAG, "kv add subs %s := %s", key, subst);
+    struct tpl_kv_entry *entry = calloc(1, sizeof(struct tpl_kv_entry));
+    if (entry == NULL) return ESP_ERR_NO_MEM;
+
+    assert(strlen(key) < TPL_KV_KEY_LEN);
+    assert(strlen(subst) < TPL_KV_SUBST_LEN);
+
+    strncpy(entry->key, key, TPL_KV_KEY_LEN);
+    entry->key[TPL_KV_KEY_LEN - 1] = 0;
+
+    strncpy(entry->subst, subst, TPL_KV_SUBST_LEN - 1);
+    entry->subst[TPL_KV_KEY_LEN - 1] = 0;
+
+    SLIST_INSERT_HEAD(head, entry, link);
+    return ESP_OK;
+}
+
+esp_err_t tpl_kv_add_heapstr(struct tpl_kv_list *head, const char *key, char *subst)
+{
+    ESP_LOGD(TAG, "kv add subs %s := (heap str)", key);
+    struct tpl_kv_entry *entry = calloc(1, sizeof(struct tpl_kv_entry));
+    if (entry == NULL) return ESP_ERR_NO_MEM;
+
+    assert(strlen(key) < TPL_KV_KEY_LEN);
+
+    strncpy(entry->key, key, TPL_KV_KEY_LEN);
+    entry->key[TPL_KV_KEY_LEN - 1] = 0;
+
+    entry->subst_heap = subst;
+
+    SLIST_INSERT_HEAD(head, entry, link);
+    return ESP_OK;
+}
+
+esp_err_t tpl_kv_sprintf(struct tpl_kv_list *head, const char *key, const char *format, ...)
+{
+    ESP_LOGD(TAG, "kv printf %s := %s", key, format);
+    struct tpl_kv_entry *entry = calloc(1, sizeof(struct tpl_kv_entry));
+    if (entry == NULL) return ESP_ERR_NO_MEM;
+
+    assert(strlen(key) < TPL_KV_KEY_LEN);
+
+    strncpy(entry->key, key, TPL_KV_KEY_LEN);
+    entry->key[TPL_KV_KEY_LEN - 1] = 0;
+
+    va_list list;
+    va_start(list, format);
+    vsnprintf(entry->subst, TPL_KV_SUBST_LEN, format, list);
+    va_end(list);
+    entry->subst[TPL_KV_KEY_LEN - 1] = 0;
+
+    SLIST_INSERT_HEAD(head, entry, link);
+    return ESP_OK;
+}
+
+void tpl_kv_free(struct tpl_kv_list *head)
+{
+    struct tpl_kv_entry *item, *next;
+    SLIST_FOREACH_SAFE(item, head, link, next) {
+        if (item->subst_heap) {
+            free(item->subst_heap);
+            item->subst_heap = NULL;
+        }
+
+        free(item);
+    }
+}
+
+esp_err_t tpl_kv_send_as_ascii_map(httpd_req_t *req, struct tpl_kv_list *head)
+{
+    httpd_resp_set_type(req, "text/plain; charset=utf-8");
+
+#define BUF_CAP 512
+    char *buf_head = malloc(BUF_CAP);
+    if (!buf_head) {
+        ESP_LOGE(TAG, "Malloc err");
+        return ESP_FAIL;
+    }
+    char *buf = buf_head;
+    size_t cap = BUF_CAP;
+    struct tpl_kv_entry *entry;
+
+    // GCC nested function
+    esp_err_t send_part() {
+        esp_err_t suc = httpd_resp_send_chunk(req, buf_head, BUF_CAP-cap);
+        buf = buf_head; // buf is assigned to buf head
+        cap = BUF_CAP;
+        if (suc != ESP_OK) {
+            ESP_LOGE(TAG, "Error sending buffer");
+            free(buf_head);
+            httpd_resp_send_chunk(req, NULL, 0);
+        }
+        return suc;
+    }
+
+    SLIST_FOREACH(entry, head, link) {
+        while(NULL == (buf = append(buf, entry->key, &cap))) ESP_TRY(send_part());
+        while(NULL == (buf = append(buf, "\x1f", &cap))) ESP_TRY(send_part());
+
+        if (entry->subst_heap) {
+            if (strlen(entry->subst_heap) >= BUF_CAP) {
+                // send what we have
+                ESP_TRY(send_part());
+                esp_err_t suc = httpd_resp_send_chunk(req, entry->subst_heap, -1);
+                if (suc != ESP_OK) {
+                    ESP_LOGE(TAG, "Error sending buffer");
+                    free(buf_head);
+                    httpd_resp_send_chunk(req, NULL, 0);
+                }
+            } else {
+                while (NULL == (buf = append(buf, entry->subst_heap, &cap))) ESP_TRY(send_part());
+            }
+        } else {
+            while(NULL == (buf = append(buf, entry->subst, &cap))) ESP_TRY(send_part());
+        }
+
+        if (entry->link.sle_next) {
+            while(NULL == (buf = append(buf, "\x1e", &cap))) ESP_TRY(send_part());
+        }
+    }
+    // send leftovers
+    if (buf != buf_head) {
+        esp_err_t suc = httpd_resp_send_chunk(req, buf_head, BUF_CAP-cap);
+        if (suc != ESP_OK) {
+            ESP_LOGE(TAG, "Error sending buffer");
+        }
+    }
+
+    // Commit
+    httpd_resp_send_chunk(req, NULL, 0);
+    free(buf_head);
+    return ESP_OK;
+}

components/httpd_utils/CMakeLists.txt

@@ -0,0 +1,9 @@
+set(COMPONENT_ADD_INCLUDEDIRS
+        "include")
+
+set(COMPONENT_SRCDIRS
+        "src")
+
+set(COMPONENT_REQUIRES tcpip_adapter esp_http_server common_utils)
+
+register_component()

components/httpd_utils/README.txt

@@ -0,0 +1,4 @@
+Functions enriching the HTTP server bundled with ESP-IDF.
+This package includes HTTP-related utilities, captive
+portal implementation, and a cookie-based session system with a
+key-value store and expirations.

components/httpd_utils/component.mk

@@ -0,0 +1,3 @@
+
+COMPONENT_SRCDIRS := src
+COMPONENT_ADD_INCLUDEDIRS := include

components/httpd_utils/include/httpd_utils/captive.h

@@ -0,0 +1,32 @@
+#ifndef HTTPD_UTILS_CAPTIVE_H
+#define HTTPD_UTILS_CAPTIVE_H
+
+#include <esp_http_server.h>
+#include <esp_err.h>
+
+/**
+ * Redirect if needed when a captive portal capture is detected
+ *
+ * @param r
+ * @return ESP_OK on redirect, ESP_ERR_NOT_FOUND if not needed, other error on failure
+ */
+esp_err_t httpd_captive_redirect(httpd_req_t *r);
+
+/**
+ * Get URL to redirect to. WEAK.
+ *
+ * @param r
+ * @param buf
+ * @param maxlen
+ * @return http(s)://foo.bar/
+ */
+esp_err_t httpd_captive_redirect_get_url(httpd_req_t *r, char *buf, size_t maxlen);
+
+/**
+ * Get captive portal domain. WEAK.
+ *
+ * @return foo.bar
+ */
+const char * httpd_captive_redirect_get_domain();
+
+#endif //HTTPD_UTILS_CAPTIVE_H

components/httpd_utils/include/httpd_utils/fd_to_ipv4.h

@@ -0,0 +1,13 @@
+#ifndef HTTPD_FDIPV4_H
+#define HTTPD_FDIPV4_H
+
+/**
+ * Get IP address for a FD
+ *
+ * @param fd
+ * @param[out] ipv4
+ * @return success
+ */
+esp_err_t fd_to_ipv4(int fd, in_addr_t *ipv4);
+
+#endif //HTTPD_FDIPV4_H

components/httpd_utils/include/httpd_utils/redirect.h

@@ -0,0 +1,16 @@
+#ifndef HTTPD_UTILS_REDIRECT_H
+#define HTTPD_UTILS_REDIRECT_H
+
+#include <esp_http_server.h>
+#include <esp_err.h>
+
+/**
+ * Redirect to other URI - sends a HTTP response from the http server
+ *
+ * @param r - request
+ * @param uri - target uri
+ * @return success
+ */
+esp_err_t httpd_redirect_to(httpd_req_t *r, const char *uri);
+
+#endif // HTTPD_UTILS_REDIRECT_H

components/httpd_utils/include/httpd_utils/session.h

@@ -0,0 +1,55 @@
+/**
+ * Session store system main include file
+ *
+ * Created on 2019/07/13.
+ */
+
+#ifndef HTTPD_UTILS_SESSION_H
+#define HTTPD_UTILS_SESSION_H
+
+#include "session_kvmap.h"
+#include "session_store.h"
+
+// Customary keys
+
+/** Session key for OK flash message */
+#define SESS_FLASH_OK "flash_ok"
+/** Session key for error flash message */
+#define SESS_FLASH_ERR "flash_err"
+/** Session key for a "logged in" flag. Value is 1 if logged in. */
+#define SESS_AUTHED "authed"
+
+// ..
+
+/**
+ * Redirect to /login form if unauthed,
+ * but also retrieve the session key-value store for further use
+ */
+#define HTTP_GET_AUTHED_SESSION(kvstore, r) do {                            \
+    kvstore = httpd_req_find_session_and((r), SESS_GET_DATA);               \
+    if (NULL == kvstore || NULL == sess_kv_map_get(kvstore, SESS_AUTHED)) { \
+        return httpd_redirect_to((r), "/login");                            \
+    }                                                                       \
+} while(0)
+
+/**
+ * Start or resume a session without checking for authed status.
+ * When started, the session cookie is added to the response immediately.
+ *
+ * @param[out] kvstore - a place to store the allocated or retrieved session kvmap
+ * @param[in] r - request
+ * @return success
+ */
+esp_err_t HTTP_GET_SESSION(sess_kv_map_t **kvstore, httpd_req_t *r);
+
+/**
+ * Redirect to the login form if unauthed.
+ * This is the same as `HTTP_GET_AUTHED_SESSION`, except the kvstore variable is
+ * not needed in the uri handler calling this, so it is declared internally.
+ */
+#define HTTP_REDIRECT_IF_UNAUTHED(r) do {                             \
+    sess_kv_map_t *_kvstore;                                          \
+    HTTP_GET_AUTHED_SESSION(_kvstore, r);                             \
+} while(0)
+
+#endif // HTTPD_UTILS_SESSION_H

components/httpd_utils/include/httpd_utils/session_kvmap.h

@@ -0,0 +1,77 @@
+/**
+ * Simple key-value map for session data storage.
+ * Takes care of dynamic allocation and cleanup.
+ * 
+ * Created on 2019/01/28.
+ */
+
+#ifndef SESSION_KVMAP_H
+#define SESSION_KVMAP_H
+
+/**
+ * Prototype for a free() func to clean up session-held objects
+ */
+typedef void (*sess_kv_free_func_t)(void *obj);
+
+typedef struct sess_kv_map sess_kv_map_t;
+
+#define SESS_KVMAP_KEY_LEN 16
+
+/**
+ * Allocate a new session key-value store
+ *
+ * @return the store, NULL on error
+ */
+sess_kv_map_t *sess_kv_map_alloc(void);
+
+/**
+ * Free the session kv store.
+ *
+ * @param head - store head
+ */
+void sess_kv_map_free(void *head);
+
+/**
+ * Get a value from the session kv store.
+ *
+ * @param head - store head
+ * @param key - key to get a value for
+ * @return the value, or NULL if not found
+ */
+void *sess_kv_map_get(sess_kv_map_t *head, const char *key);
+
+/**
+ * Get and remove a value from the session store.
+ *
+ * The free function is not called in this case and the recipient is
+ * responsible for cleaning it up correctly.
+ *
+ * @param head - store head
+ * @param key - key to get a value for
+ * @return the value, or NULL if not found
+ */
+void * sess_kv_map_take(sess_kv_map_t *head, const char *key);
+
+/**
+ * Remove an entry from the session by its key name.
+ * The slot is not free'd yet, but is made available for reuse.
+ *
+ * @param head - store head
+ * @param key - key to remove
+ * @return success
+ */
+esp_err_t sess_kv_map_remove(sess_kv_map_t *head, const char *key);
+
+/**
+ * Set a key value. If there is an old value stored, it will be freed by its free function and replaced by the new one.
+ * Otherwise a new slot is allocated for it, or a previously released one is reused.
+ *
+ * @param head - store head
+ * @param key - key to assign to
+ * @param value - new value
+ * @param free_fn - value free func
+ * @return success
+ */
+esp_err_t sess_kv_map_set(sess_kv_map_t *head, const char *key, void *value, sess_kv_free_func_t free_fn);
+
+#endif //SESSION_KVMAP_H

components/httpd_utils/include/httpd_utils/session_store.h

@@ -0,0 +1,100 @@
+/**
+ * Cookie-based session store
+ */
+
+#ifndef SESSION_STORE_H
+#define SESSION_STORE_H
+
+#include "esp_http_server.h"
+
+#define SESSION_EXPIRY_TIME_S 60*30
+#define SESSION_COOKIE_NAME "SESSID"
+
+/** function that frees a session data object */
+typedef void (*sess_data_free_fn_t)(void *);
+
+enum session_find_action {
+    SESS_DROP, SESS_GET_DATA
+};
+
+/**
+ * Find session and either get data, or drop it.
+ *
+ * @param cookie
+ * @param action
+ * @return
+ */
+void *session_find_and(const char *cookie, enum session_find_action action);
+
+/**
+ * Initialize the session store.
+ * Safely empty it if initialized
+ */
+void session_store_init(void);
+
+// placeholder for when no data is stored
+#define SESSION_DUMMY ((void *) 1)
+
+/**
+ * Create a new session. Data must not be NULL, because it wouldn't be possible
+ * to distinguish between NULL value and session not found in return values.
+ * It can be e.g. 1 if no data storage is needed.
+ *
+ * @param data - data object to attach to the session
+ * @param free_fn - function that disposes of the data when the session expires
+ * @return NULL on error, or the new session ID. This is a live pointer into the session structure,
+ *         must be copied if stored, as it can become invalid at any time
+ */
+const char *session_new(void *data, sess_data_free_fn_t free_fn);
+
+/**
+ * Find a session by it's ID (from a cookie)
+ *
+ * @param cookie - session ID string
+ * @return session data (void*), or NULL
+ */
+void *session_find(const char *cookie);
+
+/**
+ * Loop through all sessions and drop these that expired.
+ */
+void session_drop_expired(void);
+
+/**
+ * Drop a session by its ID. Does nothing if not found.
+ *
+ * @param cookie - session ID string
+ */
+void session_drop(const char *cookie);
+
+/**
+ * Parse the Cookie header from a request, and do something with the corresponding session.
+ *
+ * To also delete the cookie, use req_delete_session_cookie(r)
+ *
+ * @param r - request
+ * @param action - what to do with the session
+ * @return session data, NULL if removed or not found
+ */
+void *httpd_req_find_session_and(httpd_req_t *r, enum session_find_action action);
+
+/**
+ * Add a header that deletes the session cookie
+ *
+ * @param r - request
+ */
+void httpd_resp_delete_session_cookie(httpd_req_t *r);
+
+/**
+ * Add a header that sets the session cookie.
+ *
+ * This must be called after creating a session (e.g. user logged in) to make it persistent.
+ *
+ * @attention NOT RE-ENTRANT, CAN'T BE USED AGAIN UNTIL THE REQUEST IT WAS CALLED FOR IS DISPATCHED.
+ *
+ * @param r - request
+ * @param cookie - cookie ID
+ */
+void httpd_resp_set_session_cookie(httpd_req_t *r, const char *cookie);
+
+#endif //SESSION_STORE_H

components/httpd_utils/src/captive.c

@@ -0,0 +1,106 @@
+#include <esp_wifi_types.h>
+#include <esp_wifi.h>
+#include <esp_log.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <sys/param.h>
+
+#include "httpd_utils/captive.h"
+#include "httpd_utils/fd_to_ipv4.h"
+#include "httpd_utils/redirect.h"
+#include <common_utils/utils.h>
+
+static const char *TAG="captive";
+
+const char * __attribute__((weak))
+httpd_captive_redirect_get_domain(void)
+{
+    return "fb_node.captive";
+}
+
+esp_err_t __attribute__((weak))
+httpd_captive_redirect_get_url(httpd_req_t *r, char *buf, size_t maxlen)
+{
+    buf = append(buf, "http://", &maxlen);
+    buf = append(buf, httpd_captive_redirect_get_domain(), &maxlen);
+    append(buf, "/", &maxlen);
+
+    return ESP_OK;
+}
+
+esp_err_t httpd_captive_redirect(httpd_req_t *r)
+{
+    // must be static to survive being used in the redirect header
+    static char s_buf[64];
+
+    wifi_mode_t mode = 0;
+    esp_wifi_get_mode(&mode);
+
+    // Check if we have an softap interface. No point checking IPs and hostnames if the client can't be on AP.
+    if (mode == WIFI_MODE_STA || mode == WIFI_MODE_NULL) {
+        goto no_redirect;
+    }
+
+    int fd = httpd_req_to_sockfd(r);
+
+    tcpip_adapter_ip_info_t apip;
+    tcpip_adapter_get_ip_info(TCPIP_ADAPTER_IF_AP, &apip);
+
+    u32_t client_addr;
+    if(ESP_OK != fd_to_ipv4(fd, &client_addr)) {
+        return ESP_FAIL;
+    }
+
+    ESP_LOGD(TAG, "[captive] Client addr = 0x%08x, ap addr 0x%08x, ap nmask 0x%08x",
+             client_addr,
+             apip.ip.addr,
+             apip.netmask.addr
+    );
+
+    // Check if client IP looks like from our AP dhcps
+    if ((client_addr & apip.netmask.addr) != (apip.ip.addr & apip.netmask.addr)) {
+        ESP_LOGD(TAG, "[captive] Client not in AP IP range");
+        goto no_redirect;
+    }
+
+    // Get requested hostname from the header
+    esp_err_t rv = httpd_req_get_hdr_value_str(r, "Host", s_buf, 64);
+    if (rv != ESP_OK) {
+        ESP_LOGW(TAG, "[captive] No host in request?");
+        goto no_redirect;
+    }
+
+    ESP_LOGD(TAG, "[captive] Candidate for redirect: %s%s", s_buf, r->uri);
+
+    // Never redirect if host is an IP
+    if (strlen(s_buf)>7) {
+        bool isIP = 1;
+        for (int x = 0; x < strlen(s_buf); x++) {
+            if (s_buf[x] != '.' && (s_buf[x] < '0' || s_buf[x] > '9')) {
+                isIP = 0;
+                break;
+            }
+        }
+
+        if (isIP) {
+            ESP_LOGD(TAG, "[captive] Access via IP, no redirect needed");
+            goto no_redirect;
+        }
+    }
+
+    // Redirect if host differs
+    // - this can be e.g. connectivitycheck.gstatic.com or the equivalent for ios
+
+    if (0 != strcmp(s_buf, httpd_captive_redirect_get_domain())) {
+        ESP_LOGD(TAG, "[captive] Host differs, redirecting...");
+
+        httpd_captive_redirect_get_url(r, s_buf, 64);
+        return httpd_redirect_to(r, s_buf);
+    } else {
+        ESP_LOGD(TAG, "[captive] Host is OK");
+        goto no_redirect;
+    }
+
+    no_redirect:
+    return ESP_ERR_NOT_FOUND;
+}

components/httpd_utils/src/fd_to_ipv4.c

@@ -0,0 +1,42 @@
+#include <esp_wifi_types.h>
+#include <esp_wifi.h>
+#include <esp_log.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+
+#include "httpd_utils/fd_to_ipv4.h"
+
+static const char *TAG = "fd2ipv4";
+
+/**
+ * Get IP address for a FD
+ *
+ * @param fd
+ * @param[out] ipv4
+ * @return success
+ */
+esp_err_t fd_to_ipv4(int fd, in_addr_t *ipv4)
+{
+    struct sockaddr_in6 addr;
+    size_t len = sizeof(addr);
+    int rv = getpeername(fd, (struct sockaddr *) &addr, &len);
+    if (rv != 0) {
+        ESP_LOGE(TAG, "Failed to get IP addr for fd %d", fd);
+        return ESP_FAIL;
+    }
+
+    uint32_t client_addr = 0;
+    if (addr.sin6_family == AF_INET6) {
+        // this would fail in a real ipv6 network
+        // with ipv4 the addr is simply in the last ipv6 byte
+        struct sockaddr_in6 *s = &addr;
+        client_addr = s->sin6_addr.un.u32_addr[3];
+    }
+    else {
+        struct sockaddr_in *s = (struct sockaddr_in *) &addr;
+        client_addr = s->sin_addr.s_addr;
+    }
+
+    *ipv4 = client_addr;
+    return ESP_OK;
+}

components/httpd_utils/src/redirect.c

@@ -0,0 +1,20 @@
+#include <esp_wifi_types.h>
+#include <esp_wifi.h>
+#include <esp_log.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+
+#include "httpd_utils/redirect.h"
+
+static const char *TAG="redirect";
+
+esp_err_t httpd_redirect_to(httpd_req_t *r, const char *uri)
+{
+    ESP_LOGD(TAG, "Redirect to %s", uri);
+
+    httpd_resp_set_hdr(r, "Location", uri);
+    httpd_resp_set_status(r, "303 See Other");
+    httpd_resp_set_type(r, HTTPD_TYPE_TEXT);
+    const char *msg = "Redirect";
+    return httpd_resp_send(r, msg, -1);
+}

components/httpd_utils/src/session_kvmap.c

@@ -0,0 +1,181 @@
+//#define LOG_LOCAL_LEVEL ESP_LOG_DEBUG
+
+#include <rom/queue.h>
+#include <malloc.h>
+#include <assert.h>
+#include <esp_log.h>
+#include <esp_err.h>
+#include <string.h>
+#include "httpd_utils/session_kvmap.h"
+
+static const char *TAG = "sess_kvmap";
+
+// this struct is opaque, a stub like this is sufficient for the head pointer.
+struct sess_kv_entry;
+
+/** Session head structure, dynamically allocated */
+SLIST_HEAD(sess_kv_map, sess_kv_entry);
+
+struct sess_kv_entry {
+    SLIST_ENTRY(sess_kv_entry) link;
+    char key[SESS_KVMAP_KEY_LEN];
+    void *value;
+    sess_kv_free_func_t free_fn;
+};
+
+struct sess_kv_map *sess_kv_map_alloc(void)
+{
+    ESP_LOGD(TAG, "kv store alloc");
+    struct sess_kv_map *map = malloc(sizeof(struct sess_kv_map));
+    assert(map);
+    SLIST_INIT(map);
+    return map;
+}
+
+void sess_kv_map_free(void *head_v)
+{
+    struct sess_kv_map* head = head_v;
+
+    ESP_LOGD(TAG, "kv store free");
+    assert(head);
+    struct sess_kv_entry *item, *tmp;
+    SLIST_FOREACH_SAFE(item, head, link, tmp) {
+        if (item->free_fn) {
+            item->free_fn(item->value);
+            free(item);
+        }
+    }
+    free(head);
+}
+
+
+void * sess_kv_map_get(struct sess_kv_map *head, const char *key)
+{
+    assert(head);
+    assert(key);
+    ESP_LOGD(TAG, "kv store get %s", key);
+
+    struct sess_kv_entry *item;
+    SLIST_FOREACH(item, head, link) {
+        if (0==strcmp(item->key, key)) {
+            ESP_LOGD(TAG, "got ok");
+            return item->value;
+        }
+    }
+
+    ESP_LOGD(TAG, "not found in store");
+    return NULL;
+}
+
+void * sess_kv_map_take(struct sess_kv_map *head, const char *key)
+{
+    assert(head);
+    assert(key);
+    ESP_LOGD(TAG, "kv store take %s", key);
+
+    struct sess_kv_entry *item;
+    SLIST_FOREACH(item, head, link) {
+        if (0==strcmp(item->key, key)) {
+            item->key[0] = 0;
+            item->free_fn = NULL;
+            ESP_LOGD(TAG, "taken ok");
+            return item->value;
+        }
+    }
+
+    ESP_LOGD(TAG, "not found in store");
+    return NULL;
+}
+
+esp_err_t sess_kv_map_remove(struct sess_kv_map *head, const char *key)
+{
+    assert(head);
+    assert(key);
+    ESP_LOGD(TAG, "kv store remove %s", key);
+
+    struct sess_kv_entry *item;
+    SLIST_FOREACH(item, head, link) {
+        if (0==strcmp(item->key, key)) {
+            if (item->free_fn) {
+                item->free_fn(item->value);
+            }
+            item->key[0] = 0;
+            item->value = NULL;
+            item->free_fn = NULL;
+            return ESP_OK;
+        }
+    }
+
+    ESP_LOGD(TAG, "couldn't remove, not found: %s", key);
+    return ESP_ERR_NOT_FOUND;
+}
+
+
+esp_err_t sess_kv_map_set(struct sess_kv_map *head, const char *key, void *value, sess_kv_free_func_t free_fn)
+{
+    assert(head);
+    assert(key);
+    ESP_LOGD(TAG, "kv set value for key %s", key);
+
+    size_t key_len = strlen(key);
+    if (key_len > SESS_KVMAP_KEY_LEN-1) {
+        ESP_LOGE(TAG, "Key too long: %s", key);
+        // discard illegal key
+        return ESP_FAIL;
+    }
+
+    if (key_len == 0) {
+        ESP_LOGE(TAG, "Key too short: \"%s\"", key);
+        // discard illegal key
+        return ESP_FAIL;
+    }
+
+    struct sess_kv_entry *item = NULL;
+    struct sess_kv_entry *empty_item = NULL; // found item with no content
+    SLIST_FOREACH(item, head, link) {
+        ESP_LOGD(TAG, "test item with key %s, ptr %p > %p", item->key, item, item->link.sle_next);
+        if (0 == item->key[0]) {
+            ESP_LOGD(TAG, "found an empty slot");
+            empty_item = item;
+        }
+        else if (0==strcmp(item->key, key)) {
+            ESP_LOGD(TAG, "old value replaced");
+            if (item->free_fn) {
+                item->free_fn(item->value);
+            }
+            item->value = value;
+            item->free_fn = free_fn;
+            return ESP_OK;
+        } else {
+            ESP_LOGD(TAG, "skip this one");
+        }
+    }
+
+    struct sess_kv_entry *new_item = NULL;
+
+    // insert new or reuse an empty item
+    if (empty_item) {
+        new_item = empty_item;
+        ESP_LOGD(TAG, "empty item reused (%p)", new_item);
+    } else {
+        ESP_LOGD(TAG, "alloc new item");
+        // key not found, add a new entry.
+        new_item = malloc(sizeof(struct sess_kv_entry));
+        if (!new_item) {
+            ESP_LOGE(TAG, "New entry alloc failed");
+            return ESP_ERR_NO_MEM;
+        }
+    }
+
+    strcpy(new_item->key, key);
+    new_item->free_fn = free_fn;
+    new_item->value = value;
+
+    if (!empty_item) {
+        ESP_LOGD(TAG, "insert new item into list");
+        // this item was malloc'd
+        SLIST_INSERT_HEAD(head, new_item, link);
+    }
+
+    return ESP_OK;
+}

components/httpd_utils/src/session_store.c

@@ -0,0 +1,220 @@
+//#define LOG_LOCAL_LEVEL ESP_LOG_DEBUG
+
+#include <malloc.h>
+#include <esp_log.h>
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+#include <esp_http_server.h>
+#include <rom/queue.h>
+
+#include "httpd_utils/session_store.h"
+
+// TODO add a limit on simultaneously open sessions (can cause memory exhaustion DoS)
+
+#define COOKIE_LEN 32
+static const char *TAG = "session";
+
+struct session {
+    char cookie[COOKIE_LEN + 1];
+    void *data;
+    TickType_t last_activity_time;
+    LIST_ENTRY(session) link;
+    sess_data_free_fn_t free_fn;
+};
+
+static LIST_HEAD(sessions_, session) s_store;
+
+static SemaphoreHandle_t sess_store_lock = NULL;
+static bool sess_store_inited = false;
+
+
+void session_store_init(void)
+{
+    if (sess_store_inited) {
+        xSemaphoreTake(sess_store_lock, portMAX_DELAY);
+        {
+            struct session *it, *tit;
+            LIST_FOREACH_SAFE(it, &s_store, link, tit) {
+                ESP_LOGW(TAG, "Session cookie expired: \"%s\"", it->cookie);
+                if (it->free_fn) it->free_fn(it->data);
+                // no relink, we dont care if the list breaks after this - we're removing all of it
+                free(it);
+            }
+        }
+        LIST_INIT(&s_store);
+        xSemaphoreGive(sess_store_lock);
+    } else {
+        LIST_INIT(&s_store);
+        sess_store_lock = xSemaphoreCreateMutex();
+        sess_store_inited = true;
+    }
+}
+
+/**
+ * Fill buffer with base64 symbols. Does not add a trailing null byte
+ *
+ * @param buf
+ * @param len
+ */
+static void esp_fill_random_alnum(char *buf, size_t len)
+{
+#define alphabet_len 64
+    static const char alphabet[alphabet_len] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789+/";
+
+    unsigned int seed = xTaskGetTickCount();
+
+    assert(buf != NULL);
+    for (int i = 0; i < len; i++) {
+        int index = rand_r(&seed) % alphabet_len;
+        *buf++ = (uint8_t) alphabet[index];
+    }
+}
+
+const char *session_new(void *data, sess_data_free_fn_t free_fn)
+{
+    assert(data != NULL);
+
+    struct session *item = malloc(sizeof(struct session));
+    if (item == NULL) return NULL;
+
+    item->data = data;
+    item->free_fn = free_fn;
+    esp_fill_random_alnum(item->cookie, COOKIE_LEN);
+    item->cookie[COOKIE_LEN] = 0; // add the terminator
+
+    xSemaphoreTake(sess_store_lock, portMAX_DELAY);
+    {
+        item->last_activity_time = xTaskGetTickCount();
+
+        LIST_INSERT_HEAD(&s_store, item, link);
+    }
+    xSemaphoreGive(sess_store_lock);
+
+    ESP_LOGD(TAG, "New HTTP session: %s", item->cookie);
+
+    return item->cookie;
+}
+
+void *session_find_and(const char *cookie, enum session_find_action action)
+{
+    // no point in searching if the length is wrong
+    if (strlen(cookie) != COOKIE_LEN) {
+        ESP_LOGW(TAG, "Wrong session cookie length: \"%s\"", cookie);
+        return NULL;
+    }
+
+    struct session *it = NULL;
+
+    bool found = false;
+    xSemaphoreTake(sess_store_lock, portMAX_DELAY);
+    {
+        LIST_FOREACH(it, &s_store, link) {
+            if (0==strcmp(it->cookie, cookie)) {
+                ESP_LOGD(TAG, "Session cookie matched: \"%s\"", cookie);
+
+                it->last_activity_time = xTaskGetTickCount();
+                found = true;
+                break;
+            }
+        }
+        if (found && action == SESS_DROP) {
+            if (it->free_fn) it->free_fn(it->data);
+            LIST_REMOVE(it, link);
+            free(it);
+            ESP_LOGD(TAG, "Dropped session: \"%s\"", cookie);
+        }
+    }
+    xSemaphoreGive(sess_store_lock);
+    if (found) {
+        if (action == SESS_DROP) {
+            // it was dropped inside the guarded block
+            // the return value is not used with DROP
+            return NULL;
+        }
+        else if(action == SESS_GET_DATA) {
+            return it->data;
+        }
+    }
+
+    ESP_LOGW(TAG, "Session cookie not found: \"%s\"", cookie);
+    return NULL;
+}
+
+void *session_find(const char *cookie)
+{
+    return session_find_and(cookie, SESS_GET_DATA);
+}
+
+void session_drop(const char *cookie)
+{
+    session_find_and(cookie, SESS_DROP);
+}
+
+void session_drop_expired(void)
+{
+    struct session *it;
+    struct session *tit;
+
+    xSemaphoreTake(sess_store_lock, portMAX_DELAY);
+    {
+        TickType_t now = xTaskGetTickCount();
+
+        LIST_FOREACH_SAFE(it, &s_store, link, tit) {
+            TickType_t elapsed = now - it->last_activity_time;
+            if (elapsed > pdMS_TO_TICKS(SESSION_EXPIRY_TIME_S*1000)) {
+                ESP_LOGD(TAG, "Session cookie expired: \"%s\"", it->cookie);
+                if (it->free_fn) it->free_fn(it->data);
+                LIST_REMOVE(it, link);
+                free(it);
+            }
+        }
+    }
+    xSemaphoreGive(sess_store_lock);
+}
+
+
+void *httpd_req_find_session_and(httpd_req_t *r, enum session_find_action action)
+{
+    // this could be called periodically, but it's sufficient to run it at each request
+    // it won't slow anything down unless there are hundreds of sessions
+    session_drop_expired();
+
+    static char buf[256];
+    esp_err_t rv = httpd_req_get_hdr_value_str(r, "Cookie", buf, 256);
+    if (rv == ESP_OK || rv == ESP_ERR_HTTPD_RESULT_TRUNC) {
+        ESP_LOGD(TAG, "Cookie header: %s", buf);
+
+        // probably OK, see if we have a cookie
+        char *start = strstr(buf, SESSION_COOKIE_NAME"=");
+        if (start != 0) {
+            start += strlen(SESSION_COOKIE_NAME"=");
+            char *end = strchr(start, ';');
+            if (end != NULL) *end = 0;
+
+            ESP_LOGD(TAG, "Cookie is: %s", start);
+            return session_find_and(start, action);
+        }
+    } else {
+        ESP_LOGD(TAG, "No cookie.");
+    }
+
+    return NULL;
+}
+
+void httpd_resp_delete_session_cookie(httpd_req_t *r)
+{
+    httpd_resp_set_hdr(r, "Set-Cookie", SESSION_COOKIE_NAME"=");
+}
+
+
+// Static because the value is passed and stored by reference, so it wouldn't live long enough if it was on stack,
+// and there also isn't any hook for freeing it if we used malloc(). This is an SDK bug.
+static char cookie_hdr_buf[COOKIE_LEN + 10];
+
+// !!! this must not be called concurrently from a different thread.
+// That is no problem so long as the server stays single-threaded
+void httpd_resp_set_session_cookie(httpd_req_t *r, const char *cookie)
+{
+    snprintf(cookie_hdr_buf, COOKIE_LEN + 10, "SESSID=%s", cookie);
+    httpd_resp_set_hdr(r, "Set-Cookie", cookie_hdr_buf);
+}

components/httpd_utils/src/session_utils.c

@@ -0,0 +1,41 @@
+/**
+ * TODO file description
+ * 
+ * Created on 2019/07/13.
+ */
+
+#ifndef SESSION_UTILS_C_H
+#define SESSION_UTILS_C_H
+
+#include <esp_err.h>
+#include <esp_http_server.h>
+#include "httpd_utils/session_kvmap.h"
+#include "httpd_utils/session_store.h"
+
+/**
+ * Start or resume a session.
+ */
+esp_err_t HTTP_GET_SESSION(sess_kv_map_t **ppkvstore, httpd_req_t *r)
+{
+    sess_kv_map_t *kvstore;
+    kvstore = httpd_req_find_session_and((r), SESS_GET_DATA);
+    if (NULL == kvstore) {
+        kvstore = sess_kv_map_alloc();
+        if (!kvstore) return ESP_ERR_NO_MEM;
+
+        const char *cookie = session_new(kvstore, sess_kv_map_free);
+        if (cookie == NULL) {
+            // session alloc failed
+            sess_kv_map_free(kvstore);
+            *ppkvstore = NULL;
+            return ESP_ERR_NO_MEM;
+        }
+        httpd_resp_set_session_cookie(r, cookie);
+    }
+
+    *ppkvstore = kvstore;
+    return ESP_OK;
+}
+
+
+#endif //SESSION_UTILS_C_H

main/CMakeLists.txt

@@ -16,7 +16,17 @@ set(COMPONENT_SRCS
         "graphics/font.c"
         "graphics/drawing.c"
         "graphics/bitmaps.c"
+        "web/websrv.c"
+        "files/files_enum.c"
+        "utils.c"
 )
 set(COMPONENT_ADD_INCLUDEDIRS "." "liquid" "graphics")
 
+#begin staticfiles
+# generated by rebuild_file_tables
+set(COMPONENT_EMBED_FILES
+        "files/embed/favicon.ico"
+        "files/embed/index.html")
+#end staticfiles
+
 register_component()

main/analog.c

@@ -16,6 +16,13 @@ static float measurement_celsius;
 static const adc_atten_t atten = ADC_ATTEN_DB_0;
 static const adc_unit_t unit = ADC_UNIT_1;
 
+float reg_meas_history[REG_HISTORY_LEN] = {};
+float reg_tset_history[REG_HISTORY_LEN] = {};
+uint32_t history_counter = 0;
+
+// TODO move to regulator module (make extern)
+float reg_setpoint = 125;
+
 static void analog_service(void *arg);
 
 static TaskHandle_t hAnalog;
@@ -63,7 +70,15 @@ static void __attribute__((noreturn)) analog_service(void *arg) {
 
         measurement_celsius = celsius;
 
-        vTaskDelay(pdMS_TO_TICKS(100));
+        for (int i = 0; i < REG_HISTORY_LEN-1; i++) {
+            reg_meas_history[i] = reg_meas_history[i+1];
+            reg_tset_history[i] = reg_tset_history[i+1];
+        }
+        reg_meas_history[REG_HISTORY_LEN-1] = celsius;
+        reg_tset_history[REG_HISTORY_LEN-1] = reg_setpoint;
+        history_counter = (history_counter + 1) % 20;
+
+        vTaskDelay(pdMS_TO_TICKS(500));
     }
 }
 

main/analog.h

@@ -7,6 +7,11 @@
 #ifndef REFLOWER_ANALOG_H
 #define REFLOWER_ANALOG_H
 
+#define REG_HISTORY_LEN 121
+extern float reg_meas_history[REG_HISTORY_LEN];
+extern float reg_tset_history[REG_HISTORY_LEN];
+extern uint32_t history_counter;
+
 void analog_init();
 
 float analog_read();

main/app_main.c

@@ -7,6 +7,8 @@
    CONDITIONS OF ANY KIND, either express or implied.
 */
 #include <stdio.h>
+#include <web/websrv.h>
+#include <esp_wifi.h>
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 #include "esp_system.h"
@@ -15,11 +17,68 @@
 #include "knob.h"
 #include "gui.h"
 #include "analog.h"
+#include "utils.h"
+#include "esp_event_loop.h"
+#include "nvs_flash.h"
+
+/**
+ * Application event handler
+ *
+ * @param ctx - ignored, context passed to esp_event_loop_init()
+ * @param event
+ * @return success
+ */
+static esp_err_t event_handler(void *ctx, system_event_t *event)
+{
+    switch (event->event_id) {
+        case SYSTEM_EVENT_STA_START:
+            try_reconn_if_have_wifi_creds();
+            break;
+
+        case SYSTEM_EVENT_STA_CONNECTED:
+            // we should get an IP address soon
+            break;
+
+        case SYSTEM_EVENT_STA_GOT_IP:
+//            xEventGroupSetBits(g_wifi_event_group, EG_WIFI_CONNECTED_BIT);
+            break;
+
+        case SYSTEM_EVENT_STA_DISCONNECTED:
+//            xEventGroupClearBits(g_wifi_event_group, EG_WIFI_CONNECTED_BIT);
+            try_reconn_if_have_wifi_creds();
+            break;
+
+        default:
+            break;
+    }
+
+//    dhcp_watchdog_notify(dhcp_wd, event->event_id);
+
+    return ESP_OK;
+}
+
+
+/**
+ * Initialize WiFi in station mode, try to connect if settings are stored.
+ * Set up WiFi event group & start related tasks
+ */
+static void initialise_wifi(void)
+{
+    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+    ESP_ERROR_CHECK(esp_wifi_set_storage(WIFI_STORAGE_FLASH));
+    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
+
+    ESP_ERROR_CHECK(esp_wifi_start());
+}
 
 
 void __attribute__((noreturn)) app_main()
 {
-    printf("Hello world!\n");
+    ESP_ERROR_CHECK(nvs_flash_init());
+    //ESP_ERROR_CHECK(esp_register_shutdown_handler(cspemu_run_shutdown_handlers));
+
+    ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL));
 
     gpio_config_t output = {
         .pin_bit_mask = (1<<22),
@@ -27,11 +86,29 @@ void __attribute__((noreturn)) app_main()
     };
     gpio_config(&output);
 
+    tcpip_adapter_init();
+    initialise_wifi();
+
+    // TODO add proper join procedure
+    const char *ssid = "Chlivek_2.4G";
+    const char *pass = "slepice123";
+    wifi_config_t wifi_config = {};
+    strncpy((char*) wifi_config.sta.ssid, ssid, sizeof(wifi_config.sta.ssid));
+    if (pass) {
+        strncpy((char*) wifi_config.sta.password, pass, sizeof(wifi_config.sta.password));
+    }
+    ESP_ERROR_CHECK( esp_wifi_set_mode(WIFI_MODE_STA) );
+    ESP_ERROR_CHECK( esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config) );
+    ESP_ERROR_CHECK( esp_wifi_disconnect() );
+    ESP_ERROR_CHECK( esp_wifi_connect() );
 
     gui_init();
     knob_init();
     analog_init();
 
+    try_reconn_if_have_wifi_creds();
+    websrv_init();
+
     bool level = 0;
     while (1) {
         vTaskDelay(pdMS_TO_TICKS(1000));

main/files/embed/chart.ignore.svg

@@ -0,0 +1,54 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 660 440">
+    <style>
+        .ticks, .frame {
+            stroke-width: 1px;
+            fill: none;
+            stroke: black;
+        }
+        
+        path.major {
+            stroke-width: 2px;
+        }
+        
+        .ylabels text {
+            font-size: 10px;
+            text-anchor: end;
+            font-family: Droid Sans, sans-serif;
+            vertical-align: middle;
+        }
+        
+        .grid {
+            stroke-dasharray: 4;
+            stroke: #999;
+        }
+        
+        .series {
+            stroke-width: 2px;
+            fill: none;
+        }
+    </style>
+    <g transform="translate(50,15)">
+        <path d="M100,0 v400m100,-400 v400m100,-400 v400m100,-400 v400m100,-400 v400m100,-400 v400m100,-400"
+              class="grid" transform="translate(0,0)" id="grid-v" />
+        <path d="M0,100 h600m-600,100 h600m-600,100 h600m-600,100"
+              class="grid" stroke-dashoffset="0" id="grid-h" />
+        <path d="M-10,0 h10m-10,100 h10m-10,100 h10m-10,100 h10m-10,100 h10" class="ticks" />
+        <path d="M-5,10
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,20
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,20
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,20
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5" class="ticks" />
+        <g class="series">
+            <path d="M0,400L600,0" stroke="blue" id="ser-set" />
+            <path d="M0,0L300,100L600,400" stroke="red" id="ser-actual" />
+        </g>
+        <path d="M0,0h600v400h-600Z" class="frame" />
+        <g class="ylabels" transform="translate(0,3)">
+            <text x="-15" y="0">400 °C</text>
+            <text x="-15" y="100">300 °C</text>
+            <text x="-15" y="200">200 °C</text>
+            <text x="-15" y="300">100 °C</text>
+            <text x="-15" y="400">0 °C</text>
+        </g>
+    </g>
+</svg>

main/files/embed/index.html

@@ -0,0 +1,137 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+<title>Breadflow Web Control</title>
+<style>
+    * {
+        box-sizing: content-box;
+    }
+    h1 { 
+        text-align: center;
+    }
+    #ctab {
+        width: 1400px;
+        margin: 0 auto;
+        border: 1px solid #ccc; 
+        border-collapse: collapse;
+    }
+    #td-side {
+        border-left: 1px solid #ccc;
+        width: 340px;
+        padding: 15px;
+        vertical-align: top;
+        padding-top: 22px;
+    }
+    #td-img {
+        vertical-align: top;
+    }
+</style>
+</head>
+<body>
+<h1>Breadflow {version}</h1>
+
+<table id="ctab">
+<tr>
+<td id="td-img">
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 660 430">
+    <style>
+    .ticks, .frame {
+        stroke-width: 1px;
+        fill: none;
+        stroke: black;
+    }
+    
+    path.major {
+        stroke-width: 2px;
+    }
+    
+    .ylabels text {
+        font-size: 10px;
+        text-anchor: end;
+        font-family: Droid Sans, sans-serif;
+        vertical-align: middle;
+    }
+    
+    .grid {
+        stroke-dasharray: 2;
+        stroke: #dbdbdb;
+    }
+    
+    .series {
+        stroke-width: 2px;
+        fill: none;
+    }
+    </style>
+    <g transform="translate(50,15)">
+        <path d="M100,0 v400m100,-400 v400m100,-400 v400m100,-400 v400m100,-400 v400m100,-400 v400"
+            class="grid" transform="translate(0,0)" id="grid-v" />
+        <path d="M0,100 h600m-600,100 h600m-600,100 h600m-600,100"
+            class="grid" stroke-dashoffset="0" id="grid-h" />
+        <path d="M-10,0 h10m-10,100 h10m-10,100 h10m-10,100 h10m-10,100 h10" class="ticks" />
+        <path d="M-5,10
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,20
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,20
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,20
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5" class="ticks" />
+        <g class="series">
+            <path d="{ser-set}" stroke="blue" id="ser-set" /><!--M0,400L600,0-->
+            <path d="{ser-act}" stroke="red" id="ser-act" /><!--M0,0L300,100L600,400-->
+        </g>
+        <path d="M0,0h600v400h-600Z" class="frame" />
+        <g class="ylabels" transform="translate(0,3)">
+            <text x="-15" y="0">400 °C</text>
+            <text x="-15" y="100">300 °C</text>
+            <text x="-15" y="200">200 °C</text>
+            <text x="-15" y="300">100 °C</text>
+            <text x="-15" y="400">0 °C</text>
+        </g>
+    </g>
+</svg>
+</td>
+<td id="td-side">
+Sidebar
+</td>
+</tr>
+</table>
+
+<script>
+var Qi = function (x) { return document.getElementById(x) };
+function update(data) {
+	if (data) {
+		let rows = data.split('\x1e');
+		rows.forEach(function (v) {
+			let [k, va] = v.split('\x1f');
+			switch (k) {
+			    case 'ser-set':
+			        Qi('ser-set').setAttribute('d', va);
+			        break;
+                case 'ser-act':
+                    Qi('ser-act').setAttribute('d', va);
+                    break;
+                case 'timeshift':
+                    Qi('grid-v').setAttribute('transform', 'translate(-'+(va*5)+',0)');
+                    Qi('grid-h').setAttribute('stroke-dashoffset', -va * 5);
+                    break;
+            }
+		});
+	} else {
+		var xhr=new XMLHttpRequest();
+		xhr.onreadystatechange = function () {
+			if (xhr.readyState===4){
+				if (xhr.status===200) {
+					update(xhr.responseText);
+				}
+				setTimeout(update, 500);
+			}
+		};
+		xhr.onerror = function () {
+			setTimeout(update, 500);
+		};
+		xhr.open('GET', '/data');
+		xhr.send();
+	}
+}
+
+setTimeout(update, 500);
+</script>

main/files/files_enum.c

@@ -0,0 +1,15 @@
+// Generated by 'rebuild_file_tables'
+#include <stdint.h>
+#include "files_enum.h"
+
+extern const uint8_t _binary_favicon_ico_start[];
+extern const uint8_t _binary_favicon_ico_end[];
+extern const uint8_t _binary_index_html_start[];
+extern const uint8_t _binary_index_html_end[];
+
+const struct embedded_file_info EMBEDDED_FILE_LOOKUP[] = {
+    [FILE_FAVICON_ICO] = {_binary_favicon_ico_start, _binary_favicon_ico_end, "favicon.ico", "image/vnd.microsoft.icon"},
+    [FILE_INDEX_HTML] = {_binary_index_html_start, _binary_index_html_end, "index.html", "text/html"},
+};
+
+const size_t EMBEDDED_FILE_LOOKUP_LEN = 2;

main/files/files_enum.h

@@ -0,0 +1,13 @@
+// Generated by 'rebuild_file_tables'
+
+#ifndef _EMBEDDED_FILES_ENUM_H
+#define _EMBEDDED_FILES_ENUM_H
+
+#include "fileserver/embedded_files.h"
+
+enum embedded_file_id {
+    FILE_FAVICON_ICO = 0,
+    FILE_INDEX_HTML = 1
+};
+
+#endif // _EMBEDDED_FILES_ENUM_H

main/files/rebuild_file_tables.php

@@ -0,0 +1,163 @@
+#!/usr/bin/env php
+<?php
+// This script rebuilds the static files enum, extern symbols pointing to the embedded byte buffers,
+// and the look-up structs table. To add more files, simply add them in the 'files' directory.
+
+// Note that all files will be accessible by the webserver, unless you filter them in embedded_files.c.
+
+
+// List all files
+$files = scandir(__DIR__.'/embed');
+
+$files = array_filter(array_map(function ($f) {
+  if (!is_file(__DIR__.'/embed/'.$f)) return null;
+  if (preg_match('/^\.|\.kate-swp|\.bak$|~$|\.sh|\.ignore\..*$/', $f)) return null;
+
+  echo "Found: $f\n";
+  return $f;
+}, $files));
+
+sort($files);
+
+$formatted = array_filter(array_map(function ($f) {
+  return "\"files/embed/$f\"";
+}, $files));
+
+$cmake = file_get_contents(__DIR__.'/../CMakeLists.txt');
+
+$cmake = preg_replace('/#begin staticfiles\n.*#end staticfiles/s', 
+  "#begin staticfiles\n".
+  "# generated by rebuild_file_tables\n".
+  "set(COMPONENT_EMBED_FILES\n        ".
+  implode("\n        ", $formatted) . ")\n".
+  "#end staticfiles", 
+  $cmake);
+
+file_put_contents(__DIR__.'/../CMakeLists.txt', $cmake);
+
+
+// Generate a list of files
+
+$num = 0;
+$enum_keys = array_map(function ($f) use(&$num) {
+  $a = preg_replace("/[^A-Z0-9_]+/", "_", strtoupper($f));
+  return 'FILE_'. $a.' = '.($num++);
+}, $files);
+
+$keylist = implode(",\n    ", $enum_keys);
+
+$struct_array = [];
+
+$externs = array_map(function ($f) use (&$struct_array) {
+  $a = preg_replace("/[^A-Z0-9_]+/", "_", strtoupper($f));
+  
+  $start = '_binary_'. strtolower($a).'_start';
+  $end = '_binary_'. strtolower($a).'_end';
+  
+  static $mimes = array(
+    'txt' => 'text/plain',
+    'htm' => 'text/html',
+    'html' => 'text/html',
+    'php' => 'text/html',
+    'css' => 'text/css',
+    'js' => 'application/javascript',
+    'json' => 'application/json',
+    'xml' => 'application/xml',
+    'swf' => 'application/x-shockwave-flash',
+    'flv' => 'video/x-flv',
+    
+    'pem' => 'application/x-pem-file',
+
+    // images
+    'png' => 'image/png',
+    'jpe' => 'image/jpeg',
+    'jpeg' => 'image/jpeg',
+    'jpg' => 'image/jpeg',
+    'gif' => 'image/gif',
+    'bmp' => 'image/bmp',
+    'ico' => 'image/vnd.microsoft.icon',
+    'tiff' => 'image/tiff',
+    'tif' => 'image/tiff',
+    'svg' => 'image/svg+xml',
+    'svgz' => 'image/svg+xml',
+
+    // archives
+    'zip' => 'application/zip',
+    'rar' => 'application/x-rar-compressed',
+    'exe' => 'application/x-msdownload',
+    'msi' => 'application/x-msdownload',
+    'cab' => 'application/vnd.ms-cab-compressed',
+
+    // audio/video
+    'mp3' => 'audio/mpeg',
+    'qt' => 'video/quicktime',
+    'mov' => 'video/quicktime',
+
+    // adobe
+    'pdf' => 'application/pdf',
+    'psd' => 'image/vnd.adobe.photoshop',
+    'ai' => 'application/postscript',
+    'eps' => 'application/postscript',
+    'ps' => 'application/postscript',
+
+    // ms office
+    'doc' => 'application/msword',
+    'rtf' => 'application/rtf',
+    'xls' => 'application/vnd.ms-excel',
+    'ppt' => 'application/vnd.ms-powerpoint',
+
+    // open office
+    'odt' => 'application/vnd.oasis.opendocument.text',
+    'ods' => 'application/vnd.oasis.opendocument.spreadsheet',
+  );
+  
+  $parts = explode('.', $f);
+  $suffix = end($parts);
+  $mime = $mimes[$suffix] ?? 'application/octet-stream';
+  
+  $len = filesize('embed/'.$f);
+  
+  $struct_array[] = "[FILE_$a] = {{$start}, {$end}, \"{$f}\", \"{$mime}\"},";
+  
+  return 
+    'extern const uint8_t '.$start.'[];'."\n".
+    'extern const uint8_t '.$end.'[];';
+}, $files);
+
+$externlist = implode("\n", $externs);
+$structlist = implode("\n    ", $struct_array);
+
+
+file_put_contents('files_enum.h', <<<FILE
+// Generated by 'rebuild_file_tables'
+
+#ifndef _EMBEDDED_FILES_ENUM_H
+#define _EMBEDDED_FILES_ENUM_H
+
+#include "fileserver/embedded_files.h"
+
+enum embedded_file_id {
+    $keylist
+};
+
+#endif // _EMBEDDED_FILES_ENUM_H
+
+FILE
+);
+
+$files_count = count($struct_array);
+file_put_contents("files_enum.c", <<<FILE
+// Generated by 'rebuild_file_tables'
+#include <stdint.h>
+#include "files_enum.h"
+
+$externlist
+
+const struct embedded_file_info EMBEDDED_FILE_LOOKUP[] = {
+    $structlist
+};
+
+const size_t EMBEDDED_FILE_LOOKUP_LEN = $files_count;
+
+FILE
+);

main/utils.c

@@ -0,0 +1,70 @@
+#include <soc/timer_group_struct.h>
+#include <soc/timer_group_reg.h>
+#include "esp_log.h"
+#include "esp_wifi.h"
+#include "utils.h"
+
+static const char * TAG = "utils.c";
+
+static void recon_internal(void);
+
+/**
+ * Attempt to reconnect to AP if we have SSID stored
+ */
+void try_reconn_if_have_wifi_creds(void)
+{
+    recon_internal();
+}
+
+static volatile bool recurse = false;
+
+static void recon_internal(void)
+{
+    if (recurse) {
+        ESP_LOGE(TAG, "Stopping recursion!");
+    }
+    recurse = true;
+
+    wifi_config_t wificonf;
+
+    // try to connect if we have a saved config
+    ESP_ERROR_CHECK(esp_wifi_get_config(WIFI_IF_STA, &wificonf));
+
+    if (wificonf.sta.ssid[0]) {
+        ESP_LOGI(TAG, "(Re)connecting using saved STA creds");
+        ESP_ERROR_CHECK(esp_wifi_connect());
+    } else {
+        ESP_LOGI(TAG, "No WiFi creds, no (re)conn");
+    }
+
+    recurse = false;
+}
+
+
+esp_err_t nvs_get_bool(nvs_handle handle, const char* key, bool* out_value)
+{
+    uint8_t x = (uint8_t) *out_value;
+    esp_err_t rv = nvs_get_u8(handle, key, &x);
+    if (rv == ESP_OK) {
+        *out_value = (bool)x;
+    }
+    return rv;
+}
+
+esp_err_t nvs_set_bool(nvs_handle handle, const char* key, bool value)
+{
+    return nvs_set_u8(handle, key, (uint8_t) value);
+}
+
+void feed_all_dogs(void)
+{
+    TIMERG0.wdt_wprotect=TIMG_WDT_WKEY_VALUE;
+    TIMERG0.wdt_feed=1;
+    TIMERG0.wdt_wprotect=0;
+
+    TIMERG1.wdt_wprotect=TIMG_WDT_WKEY_VALUE;
+    TIMERG1.wdt_config2=CONFIG_INT_WDT_TIMEOUT_MS*2;        //Set timeout before interrupt
+    TIMERG1.wdt_config3=CONFIG_INT_WDT_TIMEOUT_MS*4;        //Set timeout before reset
+    TIMERG1.wdt_feed=1;
+    TIMERG1.wdt_wprotect=0;
+}

main/utils.h

@@ -0,0 +1,76 @@
+/**
+ * Utilities and helpers
+ */
+
+#ifndef CSPEMU_UTILS_H
+#define CSPEMU_UTILS_H
+
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include <string.h>
+#include <nvs.h>
+#include <common_utils/utils.h>
+
+/** Error check macro for FreeRTOS status codes */
+#define RTOS_ERROR_CHECK(code) if (pdPASS != (code)) ESP_ERROR_CHECK(ESP_FAIL);
+
+/** Error check macro for NULL return value */
+#define NULL_CHECK(code) if (NULL == (code)) ESP_ERROR_CHECK(ESP_FAIL);
+
+/** Error check macro for CSP status codes */
+#define CSP_ERROR_CHECK(code) if (CSP_ERR_NONE != (code)) ESP_ERROR_CHECK(ESP_FAIL);
+
+/**
+ * Reconnect to WiFi if there are saved credentials.
+ * Called from the main event group handler.
+ */
+void try_reconn_if_have_wifi_creds(void);
+
+/**
+ * Helper to retrieve a bool value from the NVS. Internally uses 'u8'
+ *
+ * @param handle - NVS storage
+ * @param key
+ * @param out_value
+ * @return success
+ */
+esp_err_t nvs_get_bool(nvs_handle handle, const char* key, bool* out_value);
+
+/**
+ * Helper to store a bool into the NVS. Internally uses 'u8'
+ *
+ * @param handle - NVS storage
+ * @param key
+ * @param value
+ * @return success
+ */
+esp_err_t nvs_set_bool(nvs_handle handle, const char* key, bool value);
+
+/**
+ * Feed watchdogs (inside a busy wait loop)
+ */
+void feed_all_dogs(void);
+
+/**
+ * @brief     malloc() and snprintf() combined
+ * @attention DO NOT use in if/for/do etc without braces.
+ *
+ * The caller is responsible for disposing of the allocated string afterwards.
+ */
+#define malloc_sprintf(var, n, format, ...) \
+    char *var = malloc(n); \
+    if (!var) assert(0); \
+    snprintf(var, n, format, ##__VA_ARGS__);
+
+/**
+ * Generate externs for an embedded file.
+ * Variables {varname} and {varname}_end will be produced.
+ */
+#define efile(varname, filename) \
+    extern const char varname[] asm("_binary_"filename"_start"); \
+    extern const char varname##_end[] asm("_binary_"filename"_end");
+
+/** Get embedded file size (must be declared with efile() first) */
+#define efsize(varname) (varname##_end - varname)
+
+#endif //CSPEMU_UTILS_H

main/version.h

@@ -0,0 +1,12 @@
+/**
+ * TODO file description
+ * 
+ * Created on 2020/01/06.
+ */
+
+#ifndef REFLOWER_VERSION_H
+#define REFLOWER_VERSION_H
+
+#define APP_VERSION "0.1"
+
+#endif //REFLOWER_VERSION_H

main/web/websrv.c

@@ -0,0 +1,212 @@
+#include <esp_log.h>
+#include <esp_err.h>
+
+#include <fileserver/token_subs.h>
+#include <httpd_utils/captive.h>
+
+#include "websrv.h"
+#include "esp_http_server.h"
+#include "utils.h"
+#include "files/files_enum.h"
+#include "version.h"
+#include "analog.h"
+
+static const char *TAG="websrv";
+
+static httpd_handle_t s_hServer = NULL;
+
+// Embedded files (must also be listed in CMakeLists.txt as COMPONENT_EMBED_TXTFILES)
+efile(index_file, "index_html");
+
+static struct tpl_kv_list build_index_replacements_kv(void)
+{
+//    char name[TPL_KV_KEY_LEN];
+    struct tpl_kv_list kv = tpl_kv_init();
+    tpl_kv_add(&kv, "version", APP_VERSION);
+
+    size_t pcap1 = 300;
+    size_t pcap2 = 300;
+    char *path1 = malloc(pcap1);
+    char *path2 = malloc(pcap2);
+    assert(path1);
+    assert(path2);
+    path1[0] = 0;
+    path2[0] = 0;
+
+#define SCRATCH_SIZE 15
+    char scratch1[SCRATCH_SIZE];
+    char scratch2[SCRATCH_SIZE];
+
+    bool last_empty = true; // first is move
+    bool suc;
+    for (int i = 0; i < REG_HISTORY_LEN; i++) {
+        int x = i*5;
+        if (reg_meas_history[i] == 0) {
+            snprintf(scratch1, SCRATCH_SIZE, "M%d,0", x);
+            snprintf(scratch2, SCRATCH_SIZE, "M%d,0", x);
+            last_empty = true;
+        } else {
+            snprintf(scratch1, SCRATCH_SIZE, "%c%d,%d", last_empty ? 'M' : 'L', x, (int)(400 - reg_meas_history[i]));
+            snprintf(scratch2, SCRATCH_SIZE, "%c%d,%d", last_empty ? 'M' : 'L', x, (int)(400 - reg_tset_history[i]));
+            last_empty = false;
+        }
+
+        suc = append_realloc(&path1, &pcap1, scratch1);
+        assert(suc);
+
+        suc = append_realloc(&path2, &pcap2, scratch2);
+        assert(suc);
+    }
+    tpl_kv_add_heapstr(&kv, "ser-act", path1);
+    tpl_kv_add_heapstr(&kv, "ser-set", path2);
+
+    tpl_kv_add_int(&kv, "timeshift", history_counter);
+
+#undef SCRATCH_SIZE
+
+    return kv;
+}
+
+/* Main page */
+static esp_err_t handler_index(httpd_req_t *req)
+{
+    struct tpl_kv_list kv = build_index_replacements_kv();
+
+    esp_err_t suc = httpd_send_template_file(req, FILE_INDEX_HTML, tpl_kv_replacer, &kv, 0);
+    tpl_kv_free(&kv);
+    return suc;
+}
+
+/* Update XHR for new index page data */
+static esp_err_t handler_update(httpd_req_t *req)
+{
+    struct tpl_kv_list kv = build_index_replacements_kv();
+
+    esp_err_t suc = tpl_kv_send_as_ascii_map(req, &kv);
+    tpl_kv_free(&kv);
+    return suc;
+}
+
+/* Set a param */
+static esp_err_t handler_set(httpd_req_t *req)
+{
+    char buf[64];
+    int n = httpd_req_recv(req, buf, 63);
+    if (n < 0) {
+        ESP_LOGW(TAG, "rx er");
+        goto err;
+    }
+    buf[n]=0;
+
+    char keybuf[20];
+    char valbuf[20];
+    if (ESP_OK != httpd_query_key_value(buf, "key", keybuf, 20)) goto err;
+    if (ESP_OK != httpd_query_key_value(buf, "value", valbuf, 20)) goto err;
+
+    // TODO handle
+
+    return httpd_resp_send(req, NULL, 0);
+
+err:
+    return httpd_resp_send_err(req, HTTPD_400_BAD_REQUEST, NULL);
+}
+
+/* Request emulator reboot */
+static esp_err_t handler_reboot(httpd_req_t *req)
+{
+    httpd_resp_send(req, "<!DOCTYPE html><html><head>"
+                         "<meta http-equiv=\"refresh\" content=\"10; url=/\">"
+                         "</head>"
+                         "<body>"
+                         "Reboot requested. Reloading in 10 seconds.<br>"
+                         "<a href=\"/\">Try now.</a>", -1);
+
+    ESP_LOGI(TAG, "Restarting ESP...");
+    esp_restart();
+}
+
+/* An HTTP GET handler */
+static esp_err_t handler_staticfiles(httpd_req_t *r)
+{
+    const struct embedded_file_info *file;
+    const char *fname = r->user_ctx;
+    enum file_access_level access = FILE_ACCESS_PROTECTED;
+
+    // wildcard files must be public
+    if (fname == NULL) {
+        fname = r->uri + 1; // URI always starts with slash, but we dont want a slash in the file name
+        access = FILE_ACCESS_PUBLIC;
+    }
+
+#ifdef USE_CAPTIVE_PORTAL
+    // First check if this is a phone taken here by the captive portal
+    esp_err_t rv = httpd_captive_redirect(r);
+    if (rv != ESP_ERR_NOT_FOUND) return rv;
+#endif
+
+    if (ESP_OK != www_get_static_file(fname, access, &file)) {
+        ESP_LOGW(TAG, "File not found: %s", fname);
+        return httpd_resp_send_404(r);
+    }
+    else {
+        if (streq(file->mime, "text/html")) {
+            // using the template func to allow includes
+            return httpd_send_template_file_struct(r, file, /*replacer*/NULL, /*ctx*/NULL, /*opts*/0);
+        } else {
+            return httpd_send_static_file_struct(r, file, TPL_ESCAPE_NONE, 0);
+        }
+    }
+}
+
+static const httpd_uri_t routes[] = {
+    {
+        .uri = "/",
+        .method = HTTP_GET,
+        .handler = handler_index,
+    },
+    {
+        .uri = "/data",
+        .method = HTTP_GET,
+        .handler = handler_update,
+    },
+    {
+        .uri = "/set",
+        .method = HTTP_POST,
+        .handler = handler_set,
+    },
+    {
+        .uri = "/reboot",
+        .method = HTTP_GET,
+        .handler = handler_reboot,
+    },
+    {
+        .uri = "*", // any file except protected (e.g. not HTML, PEM etc)
+        .method = HTTP_GET,
+        .handler = handler_staticfiles,
+    },
+};
+
+esp_err_t websrv_init(void)
+{
+    httpd_config_t config = HTTPD_DEFAULT_CONFIG();
+    config.stack_size = 6000;
+
+    config.uri_match_fn = httpd_uri_match_wildcard;
+    config.lru_purge_enable = true;
+
+    ESP_LOGI(TAG, "Starting HTTP server on port: '%d'", config.server_port);
+
+    esp_err_t suc = httpd_start(&s_hServer, &config);
+    if (suc == ESP_OK) {
+        ESP_LOGI(TAG, "HTTP server started");
+
+        for (int i = 0; i < sizeof(routes) / sizeof(httpd_uri_t); i++) {
+            httpd_register_uri_handler(s_hServer, &routes[i]);
+        }
+
+        return ESP_OK;
+    }
+
+    ESP_LOGE(TAG, "Error starting server!");
+    return suc;
+}

main/web/websrv.h

@@ -0,0 +1,14 @@
+/**
+ * Integrated webserver
+ * 
+ * Created on 2019/07/13.
+ */
+
+#ifndef CSPEMU_WEBSRV_H
+#define CSPEMU_WEBSRV_H
+
+#include <esp_err.h>
+
+esp_err_t websrv_init(void);
+
+#endif //CSPEMU_WEBSRV_H