diff options
Diffstat (limited to 'ws_proto.c')
| -rw-r--r-- | ws_proto.c | 141 |
1 files changed, 127 insertions, 14 deletions
@@ -1,7 +1,11 @@ -#include <ctype.h> - #define RFC6455_MAGIC_KEY "258EAFA5-E914-47DA-95CA-C5AB0DC85B11" +#define WS_GET_FIN(a) ((a & 0x80) >> 7) +#define WS_GET_RESERVED(a) ((a & 0xE0) >> 4) +#define WS_GET_OP(a) ((a & 0x0F)) +#define WS_GET_MASK(a) ((a & 0x80) >> 7) +#define WS_GET_LEN(a) ((a & 0x7F)) + static size_t socks = 0; static websocket* sock = NULL; @@ -99,7 +103,7 @@ int ws_handle_new(websocket* ws){ int ws_upgrade_http(websocket* ws){ if(ws->websocket_version == 13 && ws->socket_key - && ws->want_upgrade){ + && ws->want_upgrade == 3){ if(network_send_str(ws->fd, "HTTP/1.1 101 Upgrading\r\n") || network_send_str(ws->fd, "Upgrade: websocket\r\n") || network_send_str(ws->fd, "Connection: Upgrade\r\n")){ @@ -165,6 +169,7 @@ int ws_handle_http(websocket* ws){ } } + //RFC 4.2.1 checks if(!strcmp(header, "Sec-WebSocket-Version")){ ws->websocket_version = strtoul(value, NULL, 10); } @@ -175,18 +180,123 @@ int ws_handle_http(websocket* ws){ } ws->socket_key = strdup(value); } - else if(!strcmp(header, "Upgrade") && !strcmp(value, "websocket")){ - ws->want_upgrade = 1; + else if(!strcmp(header, "Upgrade") && !strcasecmp(value, "websocket")){ + ws->want_upgrade |= 1; + } + else if(!strcmp(header, "Connection") && strstr(xstr_lower(value), "upgrade")){ + ws->want_upgrade |= 2; } //TODO parse websocket protocol offers return 0; } -int ws_frame(websocket* ws){ - //TODO check for complete WS frame - //read/handle/forward data - fprintf(stderr, "Incoming websocket data\n"); - return 0; +//returns bytes handled +size_t ws_frame(websocket* ws){ + size_t u; + uint64_t payload_length = 0; + uint16_t* payload_len16 = (uint16_t*) (ws->read_buffer + 2); + uint64_t* payload_len64 = (uint64_t*) (ws->read_buffer + 2); + uint8_t* masking_key = NULL, *payload = ws->read_buffer + 2; + + //need at least the header bits + if(ws->read_buffer_offset < 2){ + return 0; + } + + if(WS_GET_RESERVED(ws->read_buffer[0])){ + //reserved bits set without any extensions + //RFC 5.2 says we MUST close the connection + //ignoring it for now + } + + //calculate the payload length (could've used a uint64 and be done with it...) + //TODO test this for the bigger frames + payload_length = WS_GET_LEN(ws->read_buffer[1]); + if(WS_GET_MASK(ws->read_buffer[1])){ + if(ws->read_buffer_offset < 6){ + return 0; + } + masking_key = ws->read_buffer + 2; + payload = ws->read_buffer + 6; + } + + if(payload_length == 126){ + //16-bit payload length + if(ws->read_buffer_offset < 4){ + return 0; + } + payload_length = htobe16(*payload_len16); + payload = ws->read_buffer + 4; + if(WS_GET_MASK(ws->read_buffer[1])){ + if(ws->read_buffer_offset < 8){ + return 0; + } + masking_key = ws->read_buffer + 4; + payload = ws->read_buffer + 8; + } + } + else if(payload_length == 127){ + //64-bit payload length + if(ws->read_buffer_offset < 10){ + return 0; + } + payload_length = htobe64(*payload_len64); + payload = ws->read_buffer + 10; + if(WS_GET_MASK(ws->read_buffer[1])){ + if(ws->read_buffer_offset < 14){ + return 0; + } + masking_key = ws->read_buffer + 10; + payload = ws->read_buffer + 14; + } + } + + //check for complete WS frame + if(ws->read_buffer_offset < (payload - ws->read_buffer) + payload_length){ + //fprintf(stderr, "Incomplete payload: offset %lu, want %lu\n", ws->read_buffer_offset, (payload - ws->read_buffer) + payload_length); + return 0; + } + + //RFC Section 5.1: If the client sends an unmasked frame, close the connection + if(!WS_GET_MASK(ws->read_buffer[1])){ + ws_close(ws); + return 0; + } + + //unmask data + if(WS_GET_MASK(ws->read_buffer[1])){ + for(u = 0; u < payload_length; u++){ + payload[u] = payload[u] ^ masking_key[u % 4]; + } + } + + fprintf(stderr, "Incoming websocket data: %s %s OP %02X LEN %u %lu\n", + WS_GET_FIN(ws->read_buffer[0]) ? "FIN" : "CONT", + WS_GET_MASK(ws->read_buffer[1]) ? "MASK" : "CLEAR", + WS_GET_OP(ws->read_buffer[0]), + WS_GET_LEN(ws->read_buffer[1]), + payload_length); + + //handle data + switch(WS_GET_OP(ws->read_buffer[0])){ + case ws_frame_text: + fprintf(stderr, "Text payload: %.*s\n", (int) payload_length, (char*) payload); + case ws_frame_binary: + //TODO forward to peer + break; + case ws_frame_close: + //TODO close connection + break; + case ws_frame_ping: + break; + case ws_frame_pong: + break; + default: + //TODO unknown frame type received + break; + } + + return ((payload - ws->read_buffer) + payload_length); } int ws_data(websocket* ws){ @@ -234,14 +344,17 @@ int ws_data(websocket* ws){ n = -1; } } + //update read buffer offset + ws->read_buffer_offset = bytes_read; break; case ws_open: - rv |= ws_frame(ws); + ws->read_buffer_offset += bytes_read; + for(n = ws_frame(ws); n > 0 && ws->read_buffer_offset > 0; n = ws_frame(ws)){ + memmove(ws->read_buffer, ws->read_buffer + n, ws->read_buffer_offset - n); + ws->read_buffer_offset -= n; + } } - //update read buffer offset - ws->read_buffer_offset = bytes_read; - //disconnect spammy clients if(sizeof(ws->read_buffer) - ws->read_buffer_offset < 2){ fprintf(stderr, "Disconnecting misbehaving client\n"); |