initial commit
diff --git a/libwebsockets.c b/libwebsockets.c
new file mode 100644
index 0000000..9e7c1d8
--- /dev/null
+++ b/libwebsockets.c
@@ -0,0 +1,457 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <unistd.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+#include <poll.h>
+#include <sys/mman.h>
+
+#include "libwebsockets.h"
+
+void md5(const unsigned char *input, int ilen, unsigned char output[16]);
+
+void dostuff(struct libwebsocket *wsi, int sock);
+
+const struct lws_tokens lws_tokens[WSI_TOKEN_COUNT] = {
+ { "GET ", 4 },
+ { "Host:", 5 },
+ { "Connection:", 11 },
+ { "Sec-WebSocket-Key1:", 19 },
+ { "Sec-WebSocket-Key2:", 19 },
+ { "Sec-WebSocket-Protocol:", 23 },
+ { "Upgrade:", 8 },
+ { "Origin:", 7 },
+ { "\x0d\x0a", 2 },
+};
+
+int libwebsocket_init(struct libwebsocket *wsi, int port)
+{
+ int n;
+ int sockfd, newsockfd;
+ unsigned int clilen;
+ struct sockaddr_in serv_addr, cli_addr;
+ int pid;
+
+ wsi->state = WSI_STATE_CLOSED;
+ wsi->name_buffer_pos = 0;
+ wsi->response = NULL;
+
+ for (n = 0; n < WSI_TOKEN_COUNT; n++) {
+ wsi->utf8_token[n].token = NULL;
+ wsi->utf8_token[n].token_len = 0;
+ }
+
+ /* fork off a master server for this websocket server */
+
+ n = fork();
+ if (n < 0) {
+ fprintf(stderr, "Failed on forking server thread: %d\n", n);
+ exit(1);
+ }
+
+ /* we are done as far as the caller is concerned */
+
+ if (n)
+ return 0;
+
+ /* sit there listening for connects, accept and spawn session servers */
+
+ sockfd = socket(AF_INET, SOCK_STREAM, 0);
+ if (sockfd < 0)
+ fprintf(stderr, "ERROR opening socket");
+ bzero((char *) &serv_addr, sizeof(serv_addr));
+
+ serv_addr.sin_family = AF_INET;
+ serv_addr.sin_addr.s_addr = INADDR_ANY;
+ serv_addr.sin_port = htons(port);
+ if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0)
+ fprintf(stderr, "ERROR on binding");
+
+ listen(sockfd, 5);
+
+ while (1) {
+ clilen = sizeof(cli_addr);
+
+ newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);
+ if (newsockfd < 0)
+ fprintf(stderr, "ERROR on accept");
+
+ /* fork off a new server instance */
+
+ pid = fork();
+ if (pid < 0)
+ fprintf(stderr, "ERROR on fork");
+ if (!pid) {
+ close(sockfd);
+
+ /* sit in dostuff() until session socket closed */
+
+ dostuff(wsi, newsockfd);
+ exit(0);
+ } else
+ close(newsockfd);
+ }
+}
+
+void libwebsocket_close(struct libwebsocket *wsi)
+{
+ int n;
+
+ wsi->state = WSI_STATE_DEAD_SOCKET;
+
+ if (wsi->websocket_closed_callback)
+ wsi->websocket_closed_callback(wsi);
+
+ for (n = 0; n < WSI_TOKEN_COUNT; n++)
+ if (wsi->utf8_token[n].token)
+ free(wsi->utf8_token[n].token);
+
+ if (wsi->response)
+ free(wsi->response);
+}
+
+
+static int libwebsocket_parse(struct libwebsocket *wsi, unsigned char c)
+{
+ int n;
+
+ switch (wsi->parser_state) {
+ case WSI_TOKEN_GET_URI:
+ case WSI_TOKEN_HOST:
+ case WSI_TOKEN_CONNECTION:
+ case WSI_TOKEN_KEY1:
+ case WSI_TOKEN_KEY2:
+ case WSI_TOKEN_PROTOCOL:
+ case WSI_TOKEN_UPGRADE:
+ case WSI_TOKEN_ORIGIN:
+ case WSI_TOKEN_CHALLENGE:
+
+// fprintf(stderr, "WSI_TOKEN_(body %d) '%c'\n", wsi->parser_state, c);
+
+ /* collect into malloc'd buffers */
+ /* optional space swallow */
+ if (!wsi->utf8_token[wsi->parser_state].token_len && c == ' ')
+ break;
+
+ /* special case space terminator for get-uri */
+ if (wsi->parser_state == WSI_TOKEN_GET_URI && c == ' ') {
+ wsi->utf8_token[wsi->parser_state].token[
+ wsi->utf8_token[wsi->parser_state].token_len] = '\0';
+ wsi->parser_state = WSI_TOKEN_SKIPPING;
+ break;
+ }
+
+ /* allocate appropriate memory */
+ if (wsi->utf8_token[wsi->parser_state].token_len == wsi->current_alloc_len - 1) {
+ /* need to extend */
+ wsi->current_alloc_len += LWS_ADDITIONAL_HDR_ALLOC;
+ if (wsi->current_alloc_len >= LWS_MAX_HEADER_LEN) {
+ /* it's waaay to much payload, fail it */
+ strcpy(wsi->utf8_token[wsi->parser_state].token,
+ "!!! Length exceeded maximum supported !!!");
+ wsi->parser_state = WSI_TOKEN_SKIPPING;
+ break;
+ }
+ wsi->utf8_token[wsi->parser_state].token =
+ realloc(wsi->utf8_token[wsi->parser_state].token,
+ wsi->current_alloc_len);
+ }
+
+ /* bail at EOL */
+ if (wsi->parser_state != WSI_TOKEN_CHALLENGE && c == '\x0d') {
+ wsi->utf8_token[wsi->parser_state].token[
+ wsi->utf8_token[wsi->parser_state].token_len] = '\0';
+ wsi->parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
+ break;
+ }
+
+ wsi->utf8_token[wsi->parser_state].token[
+ wsi->utf8_token[wsi->parser_state].token_len++] = c;
+
+ /* special payload limiting */
+ if (wsi->parser_state == WSI_TOKEN_CHALLENGE)
+ if (wsi->utf8_token[wsi->parser_state].token_len == 8) {
+// fprintf(stderr, "Setting WSI_PARSING_COMPLETE\n");
+ wsi->parser_state = WSI_PARSING_COMPLETE;
+ break;
+ }
+
+ break;
+
+ /* collecting and checking a name part */
+ case WSI_TOKEN_NAME_PART:
+// fprintf(stderr, "WSI_TOKEN_NAME_PART '%c'\n", c);
+
+ if (wsi->name_buffer_pos == sizeof(wsi->name_buffer) - 1) {
+ /* name bigger than we can handle, skip until next */
+ wsi->parser_state = WSI_TOKEN_SKIPPING;
+ break;
+ }
+ wsi->name_buffer[wsi->name_buffer_pos++] = c;
+ wsi->name_buffer[wsi->name_buffer_pos] = '\0';
+
+ for (n = 0; n < WSI_TOKEN_COUNT; n++) {
+ if (wsi->name_buffer_pos != lws_tokens[n].token_len)
+ continue;
+ if (strcmp(lws_tokens[n].token, wsi->name_buffer))
+ continue;
+ wsi->parser_state = WSI_TOKEN_GET_URI + n;
+ wsi->current_alloc_len = LWS_INITIAL_HDR_ALLOC;
+ wsi->utf8_token[wsi->parser_state].token =
+ malloc(wsi->current_alloc_len);
+ wsi->utf8_token[wsi->parser_state].token_len = 0;
+ n = WSI_TOKEN_COUNT;
+ }
+ if (wsi->parser_state != WSI_TOKEN_NAME_PART)
+ break;
+ break;
+
+ /* skipping arg part of a name we didn't recognize */
+ case WSI_TOKEN_SKIPPING:
+// fprintf(stderr, "WSI_TOKEN_SKIPPING '%c'\n", c);
+ if (c == '\x0d')
+ wsi->parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
+ break;
+ case WSI_TOKEN_SKIPPING_SAW_CR:
+// fprintf(stderr, "WSI_TOKEN_SKIPPING_SAW_CR '%c'\n", c);
+ if (c == '\x0a')
+ wsi->parser_state = WSI_TOKEN_NAME_PART;
+ else
+ wsi->parser_state = WSI_TOKEN_SKIPPING;
+ wsi->name_buffer_pos = 0;
+ break;
+ /* we're done, ignore anything else */
+ case WSI_PARSING_COMPLETE:
+// fprintf(stderr, "WSI_PARSING_COMPLETE '%c'\n", c);
+ break;
+
+ default: /* keep gcc happy */
+ break;
+ }
+
+ return 0;
+}
+
+static int interpret_key(const char *key, unsigned int *result)
+{
+ char digits[20];
+ int digit_pos = 0;
+ const char *p = key;
+ int spaces = 0;
+
+ while (*p) {
+ if (isdigit(*p)) {
+ if (digit_pos == sizeof(digits) - 1)
+ return -1;
+ digits[digit_pos++] = *p;
+ }
+ p++;
+ }
+ digits[digit_pos] = '\0';
+ if (!digit_pos)
+ return -2;
+
+ while (*key) {
+ if (*key == ' ')
+ spaces++;
+ key++;
+ }
+
+ if (!spaces)
+ return -3;
+
+ *result = atol(digits) / spaces;
+
+ return 0;
+}
+
+
+/*
+ * We have to take care about parsing because the headers may be split
+ * into multiple fragments. They may contain unknown headers with arbitrary
+ * argument lengths.
+ */
+
+int libwebsocket_read(struct libwebsocket *wsi, unsigned char * buf, size_t len)
+{
+ size_t n;
+ char *p;
+ unsigned int key1, key2;
+ unsigned char sum[16];
+
+ switch (wsi->state) {
+ case WSI_STATE_CLOSED:
+ wsi->state = WSI_STATE_HANDSHAKE_RX;
+ wsi->parser_state = WSI_TOKEN_NAME_PART;
+ case WSI_STATE_HANDSHAKE_RX:
+
+ fprintf(stderr, "issuing %ld bytes to parser\n", len);
+
+
+ fwrite(buf, 1, len, stderr);
+ for (n = 0; n< len; n++)
+ libwebsocket_parse(wsi, *buf++);
+
+ if (wsi->parser_state != WSI_PARSING_COMPLETE)
+ break;
+
+ fprintf(stderr, "Preparing return packet\n");
+
+
+ /* Confirm we have all the necessary pieces */
+
+ if (
+ !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
+ !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
+ !wsi->utf8_token[WSI_TOKEN_ORIGIN].token_len ||
+ !wsi->utf8_token[WSI_TOKEN_HOST].token_len ||
+ !wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len ||
+ !wsi->utf8_token[WSI_TOKEN_KEY1].token_len ||
+ !wsi->utf8_token[WSI_TOKEN_KEY2].token_len) {
+
+ /* completed header processing, but missing some bits */
+ goto bail;
+ }
+
+ /* create the response packet */
+
+ wsi->response = malloc(256 +
+ wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len +
+ wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len +
+ wsi->utf8_token[WSI_TOKEN_HOST].token_len +
+ wsi->utf8_token[WSI_TOKEN_ORIGIN].token_len +
+ wsi->utf8_token[WSI_TOKEN_GET_URI].token_len +
+ wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len);
+
+
+ fprintf(stderr, "'%s;\n", wsi->utf8_token[WSI_TOKEN_HOST].token);
+
+ p = wsi->response;
+ strcpy(p, "HTTP/1.1 101 WebSocket Protocol Handshake\x0d\x0aUpgrade: WebSocket\x0d\x0a");
+ p += strlen("HTTP/1.1 101 WebSocket Protocol Handshake\x0d\x0aUpgrade: WebSocket\x0d\x0a");
+ strcpy(p, "Connection: Upgrade\x0d\x0aSec-WebSocket-Origin: ");
+ p += strlen("Connection: Upgrade\x0d\x0aSec-WebSocket-Origin: ");
+ strcpy(p, wsi->utf8_token[WSI_TOKEN_ORIGIN].token);
+ p += wsi->utf8_token[WSI_TOKEN_ORIGIN].token_len;
+ strcpy(p, "\x0d\x0aSec-WebSocket-Location: ws://");
+ p += strlen("\x0d\x0aSec-WebSocket-Location: ws://");
+ strcpy(p, wsi->utf8_token[WSI_TOKEN_HOST].token);
+ p += wsi->utf8_token[WSI_TOKEN_HOST].token_len;
+ strcpy(p, wsi->utf8_token[WSI_TOKEN_GET_URI].token);
+ p += wsi->utf8_token[WSI_TOKEN_GET_URI].token_len;
+ strcpy(p, "\x0d\x0aSec-WebSocket-Protocol: ");
+ p += strlen("\x0d\x0aSec-WebSocket-Protocol: ");
+ if (wsi->utf8_token[WSI_TOKEN_PROTOCOL].token) {
+ strcpy(p, wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
+ p += wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len;
+ }
+ strcpy(p, "\x0d\x0a\x0d\x0a");
+ p += strlen("\x0d\x0a\x0d\x0a");
+
+ if (interpret_key(wsi->utf8_token[WSI_TOKEN_KEY1].token, &key1))
+ goto bail;
+
+ if (interpret_key(wsi->utf8_token[WSI_TOKEN_KEY2].token, &key2))
+ goto bail;
+
+ sum[0] = key1 >> 24;
+ sum[1] = key1 >> 16;
+ sum[2] = key1 >> 8;
+ sum[3] = key1;
+ sum[4] = key2 >> 24;
+ sum[5] = key2 >> 16;
+ sum[6] = key2 >> 8;
+ sum[7] = key2;
+ memcpy(&sum[8], wsi->utf8_token[WSI_TOKEN_CHALLENGE].token, 8);
+
+ md5(sum, 16, (unsigned char *)p);
+ p += 16;
+
+ wsi->response_length = p - wsi->response;
+
+ wsi->state = WSI_STATE_ISSUE_HANDSHAKE;
+
+ if (wsi->websocket_established_callback)
+ wsi->websocket_established_callback(wsi);
+ break;
+
+ case WSI_STATE_ESTABLISHED:
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+
+bail:
+ libwebsocket_close(wsi);
+ return -1;
+}
+
+
+void dostuff(struct libwebsocket *wsi, int sock)
+{
+ int n;
+ unsigned char buf[256];
+ struct pollfd fds;
+
+ wsi->sock = sock;
+
+ fds.fd = sock;
+ fds.events = POLLIN | POLLOUT;
+
+ while (1) {
+
+ n = poll(&fds, 1, 10);
+ if (n < 0) {
+ fprintf(stderr, "Socket dead (poll = %d)\n", n);
+ return;
+ }
+
+ if (fds.revents & (POLLERR | POLLHUP)) {
+ fprintf(stderr, "Socket dead\n");
+ return;
+ }
+
+ if (wsi->state == WSI_STATE_DEAD_SOCKET)
+ return;
+
+
+ if (fds.revents & POLLIN) {
+
+// fprintf(stderr, "POLLIN\n");
+
+ n = read(sock, buf, sizeof(buf));
+ if (n < 0) {
+ fprintf(stderr, "Socket read returned %d\n", n);
+ continue;
+ }
+ if (n)
+ libwebsocket_read(wsi, buf, n);
+ }
+
+ if (wsi->state == WSI_STATE_ISSUE_HANDSHAKE) {
+
+ fprintf(stderr, "issuing response packet %d len\n", wsi->response_length);
+
+ fwrite(wsi->response, 1, wsi->response_length, stderr);
+
+ n = write(sock, wsi->response, wsi->response_length);
+ if (n < 0) {
+ fprintf(stderr, "ERROR writing to socket");
+ exit(1);
+ }
+ wsi->state = WSI_STATE_ESTABLISHED;
+ continue;
+ }
+
+ if (wsi->websocket_send_callback)
+ wsi->websocket_send_callback(wsi);
+ }
+}
+