mongoose/examples/complete/main.c
2021-07-25 10:22:56 +01:00

206 lines
7.2 KiB
C

// Copyright (c) 2020 Cesanta Software Limited
// All rights reserved
#include "mjson.h"
#include "mongoose.h"
// Authenticated user.
// A user can be authenticated by:
// - a name:pass pair
// - a token
// When a user is shown a login screen, she enters a user:pass. If successful,
// a server returns user info which includes token. From that point on,
// client can use token for authentication. Tokens could be refreshed/changed
// on a server side, forcing clients to re-login.
struct user {
const char *name, *pass, *token;
};
// This is a configuration structure we're going to show on a dashboard
static struct config {
int value1;
char *value2;
} s_config = {123, NULL};
// Stringifies the config. A caller must free() it.
static char *stringify_config(struct config *cfg) {
char *s = NULL;
mjson_printf(mjson_print_dynamic_buf, &s, "{%Q:%d,%Q:%Q}", "value1",
cfg->value1, "value2", cfg->value2);
return s;
}
// Update config structure. Return true if changed, false otherwise
static bool update_config(struct mg_http_message *hm, struct config *cfg) {
bool changed = false;
char buf[256];
double dv;
if (mjson_get_number(hm->body.ptr, hm->body.len, "$.value1", &dv)) {
cfg->value1 = dv;
changed = true;
}
if (mjson_get_string(hm->body.ptr, hm->body.len, "$.value2", buf,
sizeof(buf)) > 0) {
free(cfg->value2);
cfg->value2 = strdup(buf);
changed = true;
}
return changed;
}
// Parse HTTP requests, return authenticated user or NULL
static struct user *getuser(struct mg_http_message *hm) {
// In production, make passwords strong and tokens randomly generated
// In this example, user list is kept in RAM. In production, it can
// be backed by file, database, or some other method.
static struct user users[] = {
{"admin", "admin", "admin_token"},
{"user1", "pass1", "user1_token"},
{"user2", "pass2", "user2_token"},
{NULL, NULL, NULL},
};
char user[256], pass[256];
struct user *u;
mg_http_creds(hm, user, sizeof(user), pass, sizeof(pass));
if (user[0] != '\0' && pass[0] != '\0') {
// Both user and password is set, search by user/password
for (u = users; u->name != NULL; u++)
if (strcmp(user, u->name) == 0 && strcmp(pass, u->pass) == 0) return u;
} else if (user[0] == '\0') {
// Only password is set, search by token
for (u = users; u->name != NULL; u++)
if (strcmp(pass, u->token) == 0) return u;
}
return NULL;
}
// Notify all config watchers about the config change
static void notify_config_change(struct mg_mgr *mgr) {
struct mg_connection *c;
char *s = stringify_config(&s_config);
for (c = mgr->conns; c != NULL; c = c->next) {
if (c->label[0] == 'W') mg_http_printf_chunk(c, "%s\n", s);
}
free(s);
}
// HTTP request handler function
static void cb(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
if (ev == MG_EV_HTTP_MSG) {
struct mg_http_message *hm = (struct mg_http_message *) ev_data;
struct user *u = getuser(hm);
// LOG(LL_INFO, ("%p [%.*s] auth %s", c->fd, (int) hm->uri.len, hm->uri.ptr,
// u ? u->name : "NULL"));
if (u == NULL && mg_http_match_uri(hm, "/api/#")) {
// All URIs starting with /api/ must be authenticated
mg_printf(c, "%s", "HTTP/1.1 403 Denied\r\nContent-Length: 0\r\n\r\n");
} else if (mg_http_match_uri(hm, "/api/config/get")) {
char *s = stringify_config(&s_config);
mg_printf(c, "HTTP/1.1 200 OK\r\nContent-Length: %d\r\n\r\n%s\n",
(int) strlen(s) + 1, s);
free(s);
} else if (mg_http_match_uri(hm, "/api/config/set")) {
// Admins only
if (strcmp(u->name, "admin") == 0) {
if (update_config(hm, &s_config)) notify_config_change(fn_data);
mg_printf(c, "HTTP/1.1 200 OK\r\nContent-Length: 0\r\n\r\n");
} else {
mg_printf(c, "%s", "HTTP/1.1 403 Denied\r\nContent-Length: 0\r\n\r\n");
}
} else if (mg_http_match_uri(hm, "/api/config/watch")) {
c->label[0] = 'W'; // Mark ourselves as a config watcher
mg_printf(c, "HTTP/1.1 200 OK\r\nTransfer-Encoding: chunked\r\n\r\n");
} else if (mg_http_match_uri(hm, "/api/video1")) {
c->label[0] = 'S'; // Mark that connection as live streamer
mg_printf(
c, "%s",
"HTTP/1.0 200 OK\r\n"
"Cache-Control: no-cache\r\n"
"Pragma: no-cache\r\nExpires: Thu, 01 Dec 1994 16:00:00 GMT\r\n"
"Content-Type: multipart/x-mixed-replace; boundary=--foo\r\n\r\n");
} else if (mg_http_match_uri(hm, "/api/log/static")) {
mg_http_serve_file(c, hm, "log.txt", "text/plain", "");
} else if (mg_http_match_uri(hm, "/api/log/live")) {
c->label[0] = 'L'; // Mark that connection as live log listener
mg_printf(c, "HTTP/1.1 200 OK\r\nTransfer-Encoding: chunked\r\n\r\n");
} else if (mg_http_match_uri(hm, "/api/login")) {
mg_printf(c, "HTTP/1.1 200 OK\r\nTransfer-Encoding: chunked\r\n\r\n");
mg_http_printf_chunk(c, "{\"user\":\"%s\",\"token\":\"%s\"}\n", u->name,
u->token);
mg_http_printf_chunk(c, "");
} else {
struct mg_http_serve_opts opts = {0};
opts.root_dir = "web_root";
mg_http_serve_dir(c, ev_data, &opts);
}
}
}
// The image stream is simulated by sending MJPEG frames specified by the
// "files" array of file names.
static void broadcast_mjpeg_frame(struct mg_mgr *mgr) {
const char *files[] = {"images/1.jpg", "images/2.jpg", "images/3.jpg",
"images/4.jpg", "images/5.jpg", "images/6.jpg"};
size_t nfiles = sizeof(files) / sizeof(files[0]);
static size_t i;
const char *path = files[i++ % nfiles];
size_t size = 0;
char *data = mg_file_read(path, &size); // Read next file
struct mg_connection *c;
for (c = mgr->conns; c != NULL; c = c->next) {
if (c->label[0] != 'S') continue; // Skip non-stream connections
if (data == NULL || size == 0) continue; // Skip on file read error
mg_printf(c,
"--foo\r\nContent-Type: image/jpeg\r\n"
"Content-Length: %lu\r\n\r\n",
(unsigned long) size);
mg_send(c, data, size);
mg_send(c, "\r\n", 2);
}
free(data);
}
static void mjpeg_cb(void *arg) {
broadcast_mjpeg_frame(arg);
}
static void log_message(const char *filename, const char *message) {
FILE *fp = fopen(filename, "a");
if (fp != NULL) {
fprintf(fp, "%s", message);
fclose(fp);
}
}
static void broadcast_message(struct mg_mgr *mgr, const char *message) {
struct mg_connection *c;
for (c = mgr->conns; c != NULL; c = c->next) {
if (c->label[0] == 'L') mg_http_printf_chunk(c, "%s", message);
}
}
// Timer function - called periodically.
// Prepare log message. Save it to a file, and broadcast.
static void log_cb(void *arg) {
char buf[64];
snprintf(buf, sizeof(buf), "Time is: %lu\n", (unsigned long) time(NULL));
log_message("log.txt", buf);
broadcast_message(arg, buf);
}
int main(void) {
struct mg_mgr mgr;
struct mg_timer t1, t2;
mg_mgr_init(&mgr);
mg_http_listen(&mgr, "http://localhost:8000", cb, &mgr);
mg_timer_init(&t1, 500, MG_TIMER_REPEAT, mjpeg_cb, &mgr);
mg_timer_init(&t2, 1000, MG_TIMER_REPEAT, log_cb, &mgr);
for (;;) mg_mgr_poll(&mgr, 50);
mg_timer_free(&t1);
mg_timer_free(&t2);
mg_mgr_free(&mgr);
return 0;
}