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 #ifndef NGHTTP2_HELPER_H 26 #define NGHTTP2_HELPER_H 27 28 #ifdef HAVE_CONFIG_H 29 #include <config.h> 30 #endif /* HAVE_CONFIG_H */ 31 32 #include <string.h> 33 #include <stddef.h> 34 35 #include "nghttp2.h" 36 #include "nghttp2_mem.h" 37 38 #define nghttp2_min(A, B) ((A) < (B) ? (A) : (B)) 39 #define nghttp2_max(A, B) ((A) > (B) ? (A) : (B)) 40 41 #define lstreq(A, B, N) ((sizeof((A)) - 1) == (N) && memcmp((A), (B), (N)) == 0) 42 43 #define nghttp2_struct_of(ptr, type, member) \ 44 ((type *)(void *)((char *)(ptr) - offsetof(type, member))) 45 46 /* 47 * Copies 2 byte unsigned integer |n| in host byte order to |buf| in 48 * network byte order. 49 */ 50 void nghttp2_put_uint16be(uint8_t *buf, uint16_t n); 51 52 /* 53 * Copies 4 byte unsigned integer |n| in host byte order to |buf| in 54 * network byte order. 55 */ 56 void nghttp2_put_uint32be(uint8_t *buf, uint32_t n); 57 58 /* 59 * Retrieves 2 byte unsigned integer stored in |data| in network byte 60 * order and returns it in host byte order. 61 */ 62 uint16_t nghttp2_get_uint16(const uint8_t *data); 63 64 /* 65 * Retrieves 4 byte unsigned integer stored in |data| in network byte 66 * order and returns it in host byte order. 67 */ 68 uint32_t nghttp2_get_uint32(const uint8_t *data); 69 70 void nghttp2_downcase(uint8_t *s, size_t len); 71 72 /* 73 * Adjusts |*local_window_size_ptr|, |*recv_window_size_ptr|, 74 * |*recv_reduction_ptr| with |*delta_ptr| which is the 75 * WINDOW_UPDATE's window_size_increment sent from local side. If 76 * |delta| is strictly larger than |*recv_window_size_ptr|, 77 * |*local_window_size_ptr| is increased by delta - 78 * *recv_window_size_ptr. If |delta| is negative, 79 * |*local_window_size_ptr| is decreased by delta. 80 * 81 * This function returns 0 if it succeeds, or one of the following 82 * negative error codes: 83 * 84 * NGHTTP2_ERR_FLOW_CONTROL 85 * local_window_size overflow or gets negative. 86 */ 87 int nghttp2_adjust_local_window_size(int32_t *local_window_size_ptr, 88 int32_t *recv_window_size_ptr, 89 int32_t *recv_reduction_ptr, 90 int32_t *delta_ptr); 91 92 /* 93 * This function works like nghttp2_adjust_local_window_size(). The 94 * difference is that this function assumes *delta_ptr >= 0, and 95 * *recv_window_size_ptr is not decreased by *delta_ptr. 96 * 97 * This function returns 0 if it succeeds, or one of the following 98 * negative error codes: 99 * 100 * NGHTTP2_ERR_FLOW_CONTROL 101 * local_window_size overflow or gets negative. 102 */ 103 int nghttp2_increase_local_window_size(int32_t *local_window_size_ptr, 104 int32_t *recv_window_size_ptr, 105 int32_t *recv_reduction_ptr, 106 int32_t *delta_ptr); 107 108 /* 109 * Returns non-zero if the function decided that WINDOW_UPDATE should 110 * be sent. 111 */ 112 int nghttp2_should_send_window_update(int32_t local_window_size, 113 int32_t recv_window_size); 114 115 /* 116 * Copies the buffer |src| of length |len| to the destination pointed 117 * by the |dest|, assuming that the |dest| is at lest |len| bytes long 118 * . Returns dest + len. 119 */ 120 uint8_t *nghttp2_cpymem(uint8_t *dest, const void *src, size_t len); 121 122 #endif /* NGHTTP2_HELPER_H */ 123