1/* 2 * nghttp2 - HTTP/2 C Library 3 * 4 * Copyright (c) 2012 Tatsuhiro Tsujikawa 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining 7 * a copy of this software and associated documentation files (the 8 * "Software"), to deal in the Software without restriction, including 9 * without limitation the rights to use, copy, modify, merge, publish, 10 * distribute, sublicense, and/or sell copies of the Software, and to 11 * permit persons to whom the Software is furnished to do so, subject to 12 * the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be 15 * included in all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 18 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 20 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 21 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 22 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 23 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 24 */ 25#include "nghttp2_npn.h" 26 27#include <string.h> 28 29static int select_next_protocol(unsigned char **out, unsigned char *outlen, 30 const unsigned char *in, unsigned int inlen, 31 const char *key, unsigned int keylen) { 32 unsigned int i; 33 for (i = 0; i + keylen <= inlen; i += (unsigned int)(in[i] + 1)) { 34 if (memcmp(&in[i], key, keylen) == 0) { 35 *out = (unsigned char *)&in[i + 1]; 36 *outlen = in[i]; 37 return 0; 38 } 39 } 40 return -1; 41} 42 43#define NGHTTP2_HTTP_1_1_ALPN "\x8http/1.1" 44#define NGHTTP2_HTTP_1_1_ALPN_LEN (sizeof(NGHTTP2_HTTP_1_1_ALPN) - 1) 45 46int nghttp2_select_next_protocol(unsigned char **out, unsigned char *outlen, 47 const unsigned char *in, unsigned int inlen) { 48 if (select_next_protocol(out, outlen, in, inlen, NGHTTP2_PROTO_ALPN, 49 NGHTTP2_PROTO_ALPN_LEN) == 0) { 50 return 1; 51 } 52 if (select_next_protocol(out, outlen, in, inlen, NGHTTP2_HTTP_1_1_ALPN, 53 NGHTTP2_HTTP_1_1_ALPN_LEN) == 0) { 54 return 0; 55 } 56 return -1; 57} 58