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update to MG_EV_HTTP_HDRS
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@scaprile
scaprile committed Apr 10, 2024
1 parent 03c326a commit 8a335a8
Showing 1 changed file with 77 additions and 69 deletions.
146 changes: 77 additions & 69 deletions examples/file-transfer/server.c
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Original file line number Diff line number Diff line change
Expand Up @@ -25,79 +25,89 @@ static bool authuser(struct mg_http_message *hm) {
return false;
}

// Streaming upload example. Demonstrates how to use MG_EV_READ events
// to get large payload in smaller chunks. To test, use curl utility:
static void cb(struct mg_connection *c, int ev, void *ev_data) {
if (ev == MG_EV_READ) {
// Parse the incoming data ourselves. If we can parse the request,
// store two size_t variables in c->data: expected len and recv len.
size_t *data = (size_t *) c->data;
struct mg_fd *fd = (struct mg_fd *) c->fn_data; // get file descriptor
if (data[0]) { // Already parsed, receiving body
data[1] += c->recv.len;
MG_DEBUG(("Got chunk len %lu, %lu total", c->recv.len, data[1]));
fd->fs->wr(fd->fd, c->recv.buf, c->recv.len);
c->recv.len = 0; // And cleanup the receive buffer. Streaming!
if (data[1] >= data[0]) {
mg_fs_close(fd);
mg_http_reply(c, 200, "", "ok\n");
}
} else if (c->is_resp == 0) {
struct mg_http_message hm;
int n = mg_http_parse((char *) c->recv.buf, c->recv.len, &hm);
if (n < 0) mg_error(c, "Bad response");
if (n > 0) {
if (mg_http_match_uri(&hm, "/upload/#")) {
if (!authuser(&hm)) {
mg_http_reply(c, 403, "", "Denied\n");
c->is_draining = 1; // Tell mongoose to close this connection
} else if (hm.body.len > (size_t) s_max_size) {
mg_http_reply(c, 400, "", "Too long\n");
c->is_draining = 1; // Tell mongoose to close this connection
} else if (hm.uri.len == 8) { // 8: /upload/
mg_http_reply(c, 400, "", "Name required\n");
c->is_draining = 1; // Tell mongoose to close this connection
} else if (strlen(s_upld_dir) + (hm.uri.len - 8) + 2 >
MG_PATH_MAX) { // 2: MG_DIRSEP + NUL
mg_http_reply(c, 400, "", "Path is too long\n");
struct upload_state {
size_t expected; // POST data length, bytes
size_t received; // Already received bytes
void *fp; // Opened uploaded file
};

static void handle_uploads(struct mg_connection *c, int ev, void *ev_data) {
struct upload_state *us = (struct upload_state *) c->data;
struct mg_fs *fs = &mg_fs_posix;

// Catch /upload requests early, without buffering whole body
// When we receive MG_EV_HTTP_HDRS event, that means we've received all
// HTTP headers but not necessarily full HTTP body
if (ev == MG_EV_HTTP_HDRS) {
struct mg_http_message *hm = (struct mg_http_message *) ev_data;
if (mg_http_match_uri(hm, "/upload/#")) {
c->pfn = NULL; // Silence HTTP protocol handler, we'll take over
if (!authuser(hm)) {
mg_http_reply(c, 403, "", "Denied\n");
c->is_draining = 1; // Tell mongoose to close this connection
} else if (hm->body.len > (size_t) s_max_size) {
mg_http_reply(c, 400, "", "Too long\n");
c->is_draining = 1; // Tell mongoose to close this connection
} else if (hm->uri.len == 8) { // 8: /upload/
mg_http_reply(c, 400, "", "Name required\n");
c->is_draining = 1; // Tell mongoose to close this connection
} else if (strlen(s_upld_dir) + (hm->uri.len - 8) + 2 >
MG_PATH_MAX) { // 2: MG_DIRSEP + NUL
mg_http_reply(c, 400, "", "Path is too long\n");
c->is_draining = 1; // Tell mongoose to close this connection
} else {
char fpath[MG_PATH_MAX];
snprintf(fpath, MG_PATH_MAX, "%s%c", s_upld_dir, MG_DIRSEP);
strncat(fpath, hm->uri.ptr + 8, hm->uri.len - 8);
if (!mg_path_is_sane(fpath)) {
mg_http_reply(c, 400, "", "Invalid path\n");
c->is_draining = 1; // Tell mongoose to close this connection
} else {
struct mg_fd *fd;
MG_DEBUG(("Got request"));
fs->rm(fpath); // Delete file if it exists
if ((fd = fs->op(fpath, MG_FS_WRITE)) == NULL) {
mg_http_reply(c, 400, "", "open failed: %d\n", errno);
c->is_draining = 1; // Tell mongoose to close this connection
} else {
char fpath[MG_PATH_MAX];
snprintf(fpath, MG_PATH_MAX, "%s%c", s_upld_dir, MG_DIRSEP);
strncat(fpath, hm.uri.ptr + 8, hm.uri.len - 8);
if (!mg_path_is_sane(fpath)) {
mg_http_reply(c, 400, "", "Invalid path\n");
c->is_draining = 1; // Tell mongoose to close this connection
} else {
MG_DEBUG(("Got request, chunk len %lu", c->recv.len - n));
if ((fd = mg_fs_open(&mg_fs_posix, fpath, MG_FS_WRITE)) == NULL) {
mg_http_reply(c, 400, "", "open failed: %d\n", errno);
c->is_draining = 1; // Tell mongoose to close this connection
} else {
c->fn_data = fd;
c->recv.len -= n; // remove headers
data[0] = hm.body.len;
data[1] = c->recv.len;
if (c->recv.len)
fd->fs->wr(fd->fd, c->recv.buf + n, c->recv.len);
c->recv.len = 0; // consume data
if (data[1] >= data[0]) {
mg_fs_close(fd);
mg_http_reply(c, 200, "", "ok\n");
}
}
}
us->fp = fd;
us->expected = hm->body.len; // Store number of bytes we expect
mg_iobuf_del(&c->recv, 0, hm->head.len); // Delete HTTP headers
}
c->is_resp = 1; // ignore the rest of the body
} else {
struct mg_http_serve_opts opts = {0};
opts.root_dir = s_root_dir;
mg_http_serve_dir(c, &hm, &opts);
}
}
}
}
(void) ev_data;

// Catch uploaded file data for both MG_EV_READ and MG_EV_HTTP_HDRS
if (us->expected > 0 && c->recv.len > 0) {
us->received += c->recv.len;
MG_DEBUG(("Got chunk: %lu bytes, %lu so far, %lu total", c->recv.len,
us->received, us->expected));
if (us->fp) fs->wr(us->fp, c->recv.buf, c->recv.len); // Write to file
c->recv.len = 0; // Delete received data
if (us->received >= us->expected) {
// Uploaded everything. Send response back
MG_INFO(("Uploaded %lu bytes", us->received));
mg_http_reply(c, 200, NULL, "%lu ok\n", us->received);
if (us->fp) fs->cl(us->fp); // Close file
memset(us, 0, sizeof(*us)); // Cleanup upload state
c->is_draining = 1; // Close connection when response gets sent
}
}
}

static void cb(struct mg_connection *c, int ev, void *ev_data) {
if (ev == MG_EV_READ || ev == MG_EV_HTTP_HDRS) {
handle_uploads(c, ev, ev_data);
} else if (ev == MG_EV_HTTP_MSG && c->pfn != NULL) {
// Non-upload requests, we serve normally
// NOTE: handle_uploads() may delete request and reset c->pfn
struct mg_http_message *hm = (struct mg_http_message *) ev_data;
struct mg_http_serve_opts opts = {0};
opts.root_dir = s_root_dir;
mg_http_serve_dir(c, hm, &opts);
}
}

static void usage(const char *prog) {
Expand Down Expand Up @@ -159,9 +169,7 @@ int main(int argc, char *argv[]) {
signal(SIGTERM, signal_handler);
mg_log_set(s_debug_level);
mg_mgr_init(&mgr);
// use mg_listen instead of mg_http_listen to be able to override the parser
// and shape buffering
if (mg_listen(&mgr, s_listening_address, cb, NULL) == NULL) {
if (mg_http_listen(&mgr, s_listening_address, cb, NULL) == NULL) {
MG_ERROR(("Cannot listen on %s.", s_listening_address));
exit(EXIT_FAILURE);
}
Expand Down

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