introduce-client-support.patch
Signed-off-by: Andy Green <andy@warmcat.com>
diff --git a/lib/client-handshake.c b/lib/client-handshake.c
new file mode 100644
index 0000000..1ef80f4
--- /dev/null
+++ b/lib/client-handshake.c
@@ -0,0 +1,394 @@
+#include "private-libwebsockets.h"
+#include <netdb.h>
+
+
+/*
+ * In-place str to lower case
+ */
+
+void
+strtolower(char *s)
+{
+ while (*s)
+ *s++ = tolower(*s);
+}
+
+void
+libwebsocket_client_close(struct libwebsocket *wsi)
+{
+ int n = wsi->state;
+ struct libwebsocket_context *clients;
+
+ /* mark the WSI as dead and let the callback know */
+
+ wsi->state = WSI_STATE_DEAD_SOCKET;
+
+ if (wsi->protocol) {
+ if (wsi->protocol->callback && n == WSI_STATE_ESTABLISHED)
+ wsi->protocol->callback(wsi, LWS_CALLBACK_CLOSED,
+ wsi->user_space, NULL, 0);
+
+ /* remove it from the client polling list */
+ clients = wsi->protocol->owning_server;
+ if (clients)
+ for (n = 0; n < clients->fds_count; n++) {
+ if (clients->wsi[n] != wsi)
+ continue;
+ while (n < clients->fds_count - 1) {
+ clients->fds[n] = clients->fds[n + 1];
+ clients->wsi[n] = clients->wsi[n + 1];
+ }
+ /* we only have to deal with one */
+ n = clients->fds_count;
+ }
+
+ }
+
+ /* clean out any parsing allocations */
+
+ for (n = 0; n < WSI_TOKEN_COUNT; n++)
+ if (wsi->utf8_token[n].token)
+ free(wsi->utf8_token[n].token);
+
+ /* shut down reasonably cleanly */
+
+#ifdef LWS_OPENSSL_SUPPORT
+ if (use_ssl) {
+ n = SSL_get_fd(wsi->ssl);
+ SSL_shutdown(wsi->ssl);
+ close(n);
+ SSL_free(wsi->ssl);
+ } else {
+#endif
+ shutdown(wsi->sock, SHUT_RDWR);
+ close(wsi->sock);
+#ifdef LWS_OPENSSL_SUPPORT
+ }
+#endif
+}
+
+struct libwebsocket *
+libwebsocket_client_connect(struct libwebsocket_context *clients,
+ const char *address,
+ int port,
+ const char *path,
+ const char *host,
+ const char *origin,
+ const char *protocol)
+{
+ struct hostent *server_hostent;
+ struct sockaddr_in server_addr;
+ char buf[150];
+ char key_b64[150];
+ char hash[20];
+ int fd;
+ struct pollfd pfd;
+ static const char magic_websocket_guid[] =
+ "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
+ static const char magic_websocket_04_masking_guid[] =
+ "61AC5F19-FBBA-4540-B96F-6561F1AB40A8";
+ char pkt[1024];
+ char *p = &pkt[0];
+ const char * pc;
+ int len;
+ int okay = 0;
+ struct libwebsocket *wsi;
+ int n;
+
+ wsi = malloc(sizeof (struct libwebsocket));
+ if (wsi == NULL)
+ return NULL;
+
+ clients->wsi[clients->fds_count] = wsi;
+
+ wsi->ietf_spec_revision = 4;
+ wsi->name_buffer_pos = 0;
+ wsi->user_space = NULL;
+ wsi->state = WSI_STATE_CLIENT_UNCONNECTED;
+ wsi->pings_vs_pongs = 0;
+
+ for (n = 0; n < WSI_TOKEN_COUNT; n++) {
+ wsi->utf8_token[n].token = NULL;
+ wsi->utf8_token[n].token_len = 0;
+ }
+
+ /*
+ * prepare the actual connection
+ */
+
+ server_hostent = gethostbyname(address);
+ if (server_hostent == NULL) {
+ fprintf(stderr, "Unable to get host name from %s\n", address);
+ goto bail1;
+ }
+
+ wsi->sock = socket(AF_INET, SOCK_STREAM, 0);
+
+ if (wsi->sock < 0) {
+ fprintf(stderr, "Unable to open socket\n");
+ goto bail1;
+ }
+
+
+ server_addr.sin_family = AF_INET;
+ server_addr.sin_port = htons(port);
+ server_addr.sin_addr = *((struct in_addr *)server_hostent->h_addr);
+ bzero(&server_addr.sin_zero, 8);
+
+ if (connect(wsi->sock, (struct sockaddr *)&server_addr,
+ sizeof(struct sockaddr)) == -1) {
+ fprintf(stderr, "Connect failed");
+ goto bail1;
+ }
+
+ /*
+ * create the random key
+ */
+
+ fd = open(SYSTEM_RANDOM_FILEPATH, O_RDONLY);
+ if (fd < 1) {
+ fprintf(stderr, "Unable to open random device %s\n",
+ SYSTEM_RANDOM_FILEPATH);
+ goto bail2;
+ }
+ n = read(fd, hash, 16);
+ if (n != 16) {
+ fprintf(stderr, "Unable to read from random device %s\n",
+ SYSTEM_RANDOM_FILEPATH);
+ close(fd);
+ goto bail2;
+ }
+ close(fd);
+
+ lws_b64_encode_string(hash, 16, key_b64, sizeof key_b64);
+
+ /*
+ * 04 example client handshake
+ *
+ * GET /chat HTTP/1.1
+ * Host: server.example.com
+ * Upgrade: websocket
+ * Connection: Upgrade
+ * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
+ * Sec-WebSocket-Origin: http://example.com
+ * Sec-WebSocket-Protocol: chat, superchat
+ * Sec-WebSocket-Version: 4
+ */
+
+ p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a", path);
+ p += sprintf(p, "Host: %s\x0d\x0a", host);
+ p += sprintf(p, "Upgrade: websocket\x0d\x0a");
+ p += sprintf(p, "Connection: Upgrade\x0d\x0aSec-WebSocket-Key: ");
+ strcpy(p, key_b64);
+ p += strlen(key_b64);
+ p += sprintf(p, "\x0d\x0aSec-WebSocket-Origin: %s\x0d\x0a", origin);
+ if (protocol != NULL)
+ p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a", protocol);
+ p += sprintf(p, "Sec-WebSocket-Version: 4\x0d\x0a\x0d\x0a");
+
+
+ /* prepare the expected server accept response */
+
+ strcpy(buf, key_b64);
+ strcpy(&buf[strlen(buf)], magic_websocket_guid);
+
+ SHA1((unsigned char *)buf, strlen(buf), (unsigned char *)hash);
+
+ lws_b64_encode_string(hash, 20, wsi->initial_handshake_hash_base64,
+ sizeof wsi->initial_handshake_hash_base64);
+
+ /* send our request to the server */
+
+ n = send(wsi->sock, pkt, p - pkt, 0);
+
+ wsi->parser_state = WSI_TOKEN_NAME_PART;
+
+ pfd.fd = wsi->sock;
+ pfd.events = POLLIN;
+ pfd.revents = 0;
+
+ n = poll(&pfd, 1, 5000);
+ if (n < 0) {
+ fprintf(stderr, "libwebsocket_client_handshake socket error "
+ "while waiting for handshake response");
+ goto bail2;
+ }
+ if (n == 0) {
+ fprintf(stderr, "libwebsocket_client_handshake timeout "
+ "while waiting for handshake response");
+ goto bail2;
+ }
+
+ /* interpret the server response */
+
+ /*
+ * HTTP/1.1 101 Switching Protocols
+ * Upgrade: websocket
+ * Connection: Upgrade
+ * Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
+ * Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
+ * Sec-WebSocket-Protocol: chat
+ */
+
+ len = recv(wsi->sock, pkt, sizeof pkt, 0);
+ if (len < 0) {
+ fprintf(stderr, "libwebsocket_client_handshake read error\n");
+ goto bail2;
+ }
+
+ p = pkt;
+ for (n = 0; n < len; n++)
+ libwebsocket_parse(wsi, *p++);
+
+ if (wsi->parser_state != WSI_PARSING_COMPLETE) {
+ fprintf(stderr, "libwebsocket_client_handshake server response"
+ " failed parsing\n");
+ goto bail2;
+ }
+
+ /*
+ * well, what the server sent looked reasonable for syntax.
+ * Now let's confirm it sent all the necessary headers
+ */
+
+ if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
+ !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
+ !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
+ !wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len ||
+ !wsi->utf8_token[WSI_TOKEN_NONCE].token_len ||
+ (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len &&
+ protocol != NULL)) {
+ fprintf(stderr, "libwebsocket_client_handshake "
+ "missing required header\n");
+ goto bail2;
+ }
+
+ /*
+ * Everything seems to be there, now take a closer look at what is in
+ * each header
+ */
+
+ strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
+ if (strcmp(wsi->utf8_token[WSI_TOKEN_HTTP].token,
+ "101 switching protocols")) {
+ fprintf(stderr, "libwebsocket_client_handshake server sent bad"
+ " HTTP response '%s'\n",
+ wsi->utf8_token[WSI_TOKEN_HTTP].token);
+ goto bail2;
+ }
+
+ strtolower(wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
+ if (strcmp(wsi->utf8_token[WSI_TOKEN_UPGRADE].token, "websocket")) {
+ fprintf(stderr, "libwebsocket_client_handshake server sent bad"
+ " Upgrade header '%s'\n",
+ wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
+ goto bail2;
+ }
+
+ strtolower(wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
+ if (strcmp(wsi->utf8_token[WSI_TOKEN_CONNECTION].token, "upgrade")) {
+ fprintf(stderr, "libwebsocket_client_handshake server sent bad"
+ " Connection hdr '%s'\n",
+ wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
+ goto bail2;
+ }
+ /*
+ * confirm the protocol the server wants to talk was in the list of
+ * protocols we offered
+ */
+
+ if (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len) {
+
+ /* no protocol name to work from, default to first protocol */
+ wsi->protocol = &clients->protocols[0];
+
+ goto check_accept;
+ }
+
+ pc = protocol;
+ while (*pc && !okay) {
+ if ((!strncmp(pc, wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
+ wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len)) &&
+ (pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == ',' ||
+ pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == '\0')) {
+ okay = 1;
+ continue;
+ }
+ while (*pc && *pc != ',')
+ pc++;
+ while (*pc && *pc != ' ')
+ pc++;
+ }
+ if (!okay) {
+ fprintf(stderr, "libwebsocket_client_handshake server "
+ "sent bad protocol '%s'\n",
+ wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
+ goto bail2;
+ }
+
+ /*
+ * identify the selected protocol struct and set it
+ */
+ n = 0;
+ wsi->protocol = NULL;
+ while (clients->protocols[n].callback) {
+ if (strcmp(wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
+ clients->protocols[n].name) == 0)
+ wsi->protocol = &clients->protocols[n];
+ n++;
+ }
+
+ if (wsi->protocol == NULL) {
+ fprintf(stderr, "libwebsocket_client_handshake server "
+ "requested protocol '%s', which we "
+ "said we supported but we don't!\n",
+ wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
+ goto bail2;
+ }
+
+check_accept:
+ /*
+ * Confirm his accept token is the same as the one we precomputed
+ */
+
+ if (strcmp(wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
+ wsi->initial_handshake_hash_base64)) {
+ fprintf(stderr, "libwebsocket_client_handshake server sent "
+ "bad ACCEPT '%s' vs computed '%s'\n",
+ wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
+ wsi->initial_handshake_hash_base64);
+ goto bail2;
+ }
+
+ /*
+ * Calculate the masking key to use when sending data to server
+ */
+
+ strcpy(buf, key_b64);
+ p = buf + strlen(key_b64);
+ strcpy(p, wsi->utf8_token[WSI_TOKEN_NONCE].token);
+ p += wsi->utf8_token[WSI_TOKEN_NONCE].token_len;
+ strcpy(p, magic_websocket_04_masking_guid);
+ SHA1((unsigned char *)buf, strlen(buf), wsi->masking_key_04);
+
+ /* okay he is good to go */
+
+ clients->fds[clients->fds_count].fd = wsi->sock;
+ clients->fds[clients->fds_count].revents = 0;
+ clients->fds[clients->fds_count++].events = POLLIN;
+
+ wsi->state = WSI_STATE_ESTABLISHED;
+ wsi->client_mode = 1;
+
+ fprintf(stderr, "handshake OK for protocol %s\n", wsi->protocol->name);
+
+ return wsi;
+
+
+bail2:
+ libwebsocket_client_close(wsi);
+bail1:
+ free(wsi);
+
+ return NULL;
+}