Mongoose on Nuttx RTOS - serving static files from FS

[koliqi]

I want to try mongoose web server on Nuttx. When run program getting following error in screen:

NuttShell (NSH) NuttX-10.2.0
nsh> mongoose &
mongoose [6:100]
nsh> Setup network addresses
Mounting SPIFFS filesystem at target=/www with source=/dev/esp/partition/spiffs
ram disk ret = 0 allocsize 32768
1970-01-01 00:00:09 3 mongoose.c:3356:mg_listen 1 accepting on 192.168.1.172:80 (port 80)
1970-01-01 00:00:09 3 mongoose.c:3258:accept_con 2 accepted 192.168.1.67:57858
1970-01-01 00:00:09 1 mongoose.c:1332:printdiren 2 stat(/www/jquery-3.5.1.min.js): 2
1970-01-01 00:00:09 1 mongoose.c:1332:printdiren 2 stat(/www/favicon.ico): 2
1970-01-01 00:00:09 1 mongoose.c:1332:printdiren 2 stat(/www/print.html): 2
1970-01-01 00:00:09 1 mongoose.c:1332:printdiren 2 stat(/www/table.html): 2
1970-01-01 00:00:09 1 mongoose.c:1332:printdiren 2 stat(/www/index.html): 2
1970-01-01 00:00:10 3 mongoose.c:3090:read_conn 2 00100000000011 0 -1/2048 err 79
1970-01-01 00:00:10 3 mongoose.c:3119:write_conn 2 00100000000111 56 -1 err 128

on web browser (192.168.1.67), instead of index.html file getting response

Index of /

Name | Modified | Size Mongoose v.7.5

OK, mongoose see files on directory /www but can't read and submit to client index.html, instead sending something else. Problem is, mongoose can't read properly files from spiffs (flat filesystem).
Question: how to make possible to read files from spiffs, how to tell mongoose it is flat file system?

[cpq]

Mongoose uses "virtual" file system API to access files. By default, it implements a POSIX interface, and a "packed" interface. User can implement its own custom interface, using whatever filesystem available. The filesystem interface can be specified as a struct mg_http_serve_opt :: fs member. If it is left as NULL, then whatever available API is used (which is POSIX).

So, the answer to your question is: implement your own custom filesystem API, and specify it in the struct mg_http_serve_opts. You can take a look at the example at

mongoose/examples/esp32/main/main.c

Lines 29 to 32 in 2000752

	struct mg_fs fs = mg_fs_posix;
	fs.stat = my_stat;
	struct mg_http_serve_opts opts = {.root_dir = FS_ROOT, .fs = &fs};
	mg_http_serve_dir(c, hm, &opts);

- which uses a hack: a POSIX implementation gets reused, with only one function (stat) replaced. In your case, when you have a FS prefix, you need to implement all filesystem functions - see POSIX implementation at https://github.com/cesanta/mongoose/blob/2000752b2c636a5c5a57141aa80cd4c2588076b4/src/fs_posix.c and do a similar thing using SPIFFS.

Your source code should look like this:

static int my_stat(const char *path, size_t *size, time_t *mtime) {
  ...
}
static void my_list(const char *path, void (*fn)(const char *, void *), void *userdata) {
  ...
}
static void *my_open(const char *path, int flags) {
  ...
}
static void my_close(void *fd) {
  ...
}
static size_t my_read(void *fd, void *buf, size_t len) {
  ...
}
static size_t my_write(void *fd, const void *buf, size_t len) {
  ...
}
static size_t my_seek(void *fd, size_t offset) {
  ...
}

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 = ev_data;
    struct mg_fs fs = {my_stat, my_list,  my_open, my_close, my_read, my_write, my_seek};
    struct mg_http_serve_opts opts = {.root_dir = "/www", .fs = &fs};
    mg_http_serve_dir(c, hm, &opts);
  }
}