You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

272 lines
6.9 KiB

/*
* lws-minimal-http-client-post
*
* Written in 2010-2019 by Andy Green <andy@warmcat.com>
*
* This file is made available under the Creative Commons CC0 1.0
* Universal Public Domain Dedication.
*
* This demonstrates the a minimal http client using lws and POST.
*
* It POSTs both form data and a file to the form at
* https://libwebsockets.org/testserver/formtest and dumps
* the html page received generated by the POST handler.
*/
#include <libwebsockets.h>
#include <string.h>
#include <signal.h>
static int interrupted, bad = 0, status, count_clients = 1, completed;
static struct lws *client_wsi[4];
struct pss {
char body_part;
};
static int
callback_http(struct lws *wsi, enum lws_callback_reasons reason,
void *user, void *in, size_t len)
{
struct pss *pss = (struct pss *)user;
char buf[LWS_PRE + 1024], *start = &buf[LWS_PRE], *p = start,
*end = &buf[sizeof(buf) - LWS_PRE - 1];
int n;
switch (reason) {
/* because we are protocols[0] ... */
case LWS_CALLBACK_CLIENT_CONNECTION_ERROR:
lwsl_err("CLIENT_CONNECTION_ERROR: %s\n",
in ? (char *)in : "(null)");
bad = 1;
if (++completed == count_clients)
lws_cancel_service(lws_get_context(wsi));
break;
case LWS_CALLBACK_CLOSED_CLIENT_HTTP:
for (n = 0; n < count_clients; n++)
if (client_wsi[n] == wsi) {
client_wsi[n] = NULL;
bad |= status != 200;
if (++completed == count_clients)
/* abort poll wait */
lws_cancel_service(lws_get_context(wsi));
}
break;
/* ...callbacks related to receiving the result... */
case LWS_CALLBACK_ESTABLISHED_CLIENT_HTTP:
status = lws_http_client_http_response(wsi);
lwsl_user("Connected with server response: %d\n", status);
break;
case LWS_CALLBACK_RECEIVE_CLIENT_HTTP_READ:
lwsl_user("RECEIVE_CLIENT_HTTP_READ: read %d\n", (int)len);
lwsl_hexdump_notice(in, len);
return 0; /* don't passthru */
case LWS_CALLBACK_RECEIVE_CLIENT_HTTP:
n = sizeof(buf) - LWS_PRE;
if (lws_http_client_read(wsi, &p, &n) < 0)
return -1;
return 0; /* don't passthru */
case LWS_CALLBACK_COMPLETED_CLIENT_HTTP:
lwsl_user("LWS_CALLBACK_COMPLETED_CLIENT_HTTP\n");
bad |= status != 200;
/*
* Do this to mark us as having processed the completion
* so close doesn't duplicate (with pipelining, completion !=
* connection close
*/
for (n = 0; n < count_clients; n++)
if (client_wsi[n] == wsi)
client_wsi[n] = NULL;
if (++completed == count_clients)
/* abort poll wait */
lws_cancel_service(lws_get_context(wsi));
break;
/* ...callbacks related to generating the POST... */
case LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER:
/*
* Tell lws we are going to send the body next...
*/
if (!lws_http_is_redirected_to_get(wsi)) {
lwsl_user("%s: doing POST flow\n", __func__);
lws_client_http_body_pending(wsi, 1);
lws_callback_on_writable(wsi);
} else
lwsl_user("%s: doing GET flow\n", __func__);
break;
case LWS_CALLBACK_CLIENT_HTTP_WRITEABLE:
if (lws_http_is_redirected_to_get(wsi))
break;
lwsl_user("LWS_CALLBACK_CLIENT_HTTP_WRITEABLE\n");
n = LWS_WRITE_HTTP;
/*
* For a small body like this, we could prepare it in memory and
* send it all at once. But to show how to handle, eg,
* arbitrary-sized file payloads, or huge form-data fields, the
* sending is done in multiple passes through the event loop.
*/
switch (pss->body_part++) {
case 0:
if (lws_client_http_multipart(wsi, "text", NULL, NULL,
&p, end))
return -1;
/* notice every usage of the boundary starts with -- */
p += lws_snprintf(p, end - p, "my text field\xd\xa");
break;
case 1:
if (lws_client_http_multipart(wsi, "file", "myfile.txt",
"text/plain", &p, end))
return -1;
p += lws_snprintf(p, end - p,
"This is the contents of the "
"uploaded file.\xd\xa"
"\xd\xa");
break;
case 2:
if (lws_client_http_multipart(wsi, NULL, NULL, NULL,
&p, end))
return -1;
lws_client_http_body_pending(wsi, 0);
/* necessary to support H2, it means we will write no
* more on this stream */
n = LWS_WRITE_HTTP_FINAL;
break;
default:
/*
* We can get extra callbacks here, if nothing to do,
* then do nothing.
*/
return 0;
}
if (lws_write(wsi, (uint8_t *)start, lws_ptr_diff(p, start), n)
!= lws_ptr_diff(p, start))
return 1;
if (n != LWS_WRITE_HTTP_FINAL)
lws_callback_on_writable(wsi);
return 0;
default:
break;
}
return lws_callback_http_dummy(wsi, reason, user, in, len);
}
static const struct lws_protocols protocols[] = {
{
"http",
callback_http,
sizeof(struct pss),
0,
},
{ NULL, NULL, 0, 0 }
};
static void
sigint_handler(int sig)
{
interrupted = 1;
}
int main(int argc, const char **argv)
{
struct lws_context_creation_info info;
struct lws_client_connect_info i;
struct lws_context *context;
int n = 0;
signal(SIGINT, sigint_handler);
memset(&info, 0, sizeof info); /* otherwise uninitialized garbage */
lws_cmdline_option_handle_builtin(argc, argv, &info);
lwsl_user("LWS minimal http client - POST [-d<verbosity>] [-l] [--h1]\n");
if (lws_cmdline_option(argc, argv, "-m"))
count_clients = LWS_ARRAY_SIZE(client_wsi);
info.options = LWS_SERVER_OPTION_DO_SSL_GLOBAL_INIT;
info.port = CONTEXT_PORT_NO_LISTEN; /* we do not run any server */
info.protocols = protocols;
/*
* since we know this lws context is only ever going to be used with
* one client wsis / fds / sockets at a time, let lws know it doesn't
* have to use the default allocations for fd tables up to ulimit -n.
* It will just allocate for 1 internal and 1 (+ 1 http2 nwsi) that we
* will use.
*/
info.fd_limit_per_thread = 1 + count_clients + 1;
#if defined(LWS_WITH_MBEDTLS)
/*
* OpenSSL uses the system trust store. mbedTLS has to be told which
* CA to trust explicitly.
*/
if (!lws_cmdline_option(argc, argv, "-l"))
info.client_ssl_ca_filepath = "./libwebsockets.org.cer";
#endif
context = lws_create_context(&info);
if (!context) {
lwsl_err("lws init failed\n");
return 1;
}
memset(&i, 0, sizeof i); /* otherwise uninitialized garbage */
i.context = context;
i.ssl_connection = LCCSCF_USE_SSL | LCCSCF_HTTP_MULTIPART_MIME;
if (lws_cmdline_option(argc, argv, "-l")) {
i.port = 7681;
i.address = "localhost";
i.ssl_connection |= LCCSCF_ALLOW_SELFSIGNED;
i.path = "/formtest";
} else {
i.port = 443;
i.address = "libwebsockets.org";
i.path = "/testserver/formtest";
}
if (lws_cmdline_option(argc, argv, "--form1"))
i.path = "/form1";
i.host = i.address;
i.origin = i.address;
i.method = "POST";
/* force h1 even if h2 available */
if (lws_cmdline_option(argc, argv, "--h1"))
i.alpn = "http/1.1";
i.protocol = protocols[0].name;
for (n = 0; n < count_clients; n++) {
i.pwsi = &client_wsi[n];
if (!lws_client_connect_via_info(&i))
completed++;
}
while (n >= 0 && completed != count_clients && !interrupted)
n = lws_service(context, 0);
lws_context_destroy(context);
lwsl_user("Completed: %s\n", bad ? "failed" : "OK");
return bad;
}