| /* |
| * HPACK decompressor (RFC7541) |
| * |
| * Copyright (C) 2014-2017 Willy Tarreau <willy@haproxy.org> |
| * Copyright (C) 2017 HAProxy Technologies |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining |
| * a copy of this software and associated documentation files (the |
| * "Software"), to deal in the Software without restriction, including |
| * without limitation the rights to use, copy, modify, merge, publish, |
| * distribute, sublicense, and/or sell copies of the Software, and to |
| * permit persons to whom the Software is furnished to do so, subject to |
| * the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be |
| * included in all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES |
| * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT |
| * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, |
| * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
| * OTHER DEALINGS IN THE SOFTWARE. |
| */ |
| |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include <common/hpack-enc.h> |
| #include <common/http-hdr.h> |
| #include <common/ist.h> |
| |
| #include <types/global.h> |
| |
| /* returns the number of bytes required to encode the string length <len>. The |
| * number of usable bits is an integral multiple of 7 plus 6 for the last byte. |
| * The maximum number of bytes returned is 4 (2097279 max length). Larger values |
| * return 0. |
| */ |
| static inline int len_to_bytes(size_t len) |
| { |
| if (len < 127) |
| return 1; |
| if (len < 127 + (1 << 7)) |
| return 2; |
| if (len < 127 + (1 << 14)) |
| return 3; |
| if (len < 127 + (1 << 21)) |
| return 4; |
| return 0; |
| } |
| |
| /* Encode <len> into <out>+<pos> and return the new position. The caller is |
| * responsible for checking for available room using len_to_bytes() first. |
| */ |
| static inline int hpack_encode_len(char *out, int pos, int len) |
| { |
| int code = len - 127; |
| |
| if (code < 0) { |
| out[pos++] = len; |
| } else { |
| out[pos++] = 127; |
| for (; code >= 128; code >>= 7) |
| out[pos++] = code | 128; |
| out[pos++] = code; |
| } |
| return pos; |
| } |
| |
| |
| /* Tries to encode header whose name is <n> and value <v> into the chunk <out>. |
| * Returns non-zero on success, 0 on failure (buffer full). |
| */ |
| int hpack_encode_header(struct buffer *out, const struct ist n, |
| const struct ist v) |
| { |
| int len = out->data; |
| int size = out->size; |
| |
| if (len >= size) |
| return 0; |
| |
| /* check a few very common response header fields to encode them using |
| * the static header table. The tests are sorted by size to help the |
| * compiler factor out the common sizes. |
| */ |
| if (isteq(n, ist("date"))) |
| out->area[len++] = 0x61; // literal with indexing -- name="date" (idx 33) |
| else if (isteq(n, ist("etag"))) |
| out->area[len++] = 0x62; // literal with indexing -- name="etag" (idx 34) |
| else if (isteq(n, ist(":path"))) |
| out->area[len++] = 0x44; // literal with indexing -- name=":path" (idx 4) |
| else if (isteq(n, ist("server"))) |
| out->area[len++] = 0x76; // literal with indexing -- name="server" (idx 54) |
| else if (isteq(n, ist("location"))) |
| out->area[len++] = 0x6e; // literal with indexing -- name="location" (idx 46) |
| else if (isteq(n, ist("content-type"))) |
| out->area[len++] = 0x5f; // literal with indexing -- name="content-type" (idx 31) |
| else if (isteq(n, ist("last-modified"))) |
| out->area[len++] = 0x6c; // literal with indexing -- name="last-modified" (idx 44) |
| else if (isteq(n, ist("accept-ranges"))) |
| out->area[len++] = 0x52; // literal with indexing -- name="accept-ranges" (idx 18) |
| else if (isteq(n, ist("cache-control"))) |
| out->area[len++] = 0x58; // literal with indexing -- name="cache-control" (idx 24) |
| else if (isteq(n, ist("content-length"))) |
| out->area[len++] = 0x5c; // literal with indexing -- name="content-length" (idx 28) |
| else if (len_to_bytes(n.len) && len + 1 + len_to_bytes(n.len) + n.len <= size) { |
| out->area[len++] = 0x00; /* literal without indexing -- new name */ |
| |
| len = hpack_encode_len(out->area, len, n.len); |
| memcpy(out->area + len, n.ptr, n.len); |
| len += n.len; |
| } |
| else { |
| /* header field name too large for the buffer */ |
| return 0; |
| } |
| |
| /* copy literal header field value */ |
| if (!len_to_bytes(v.len) || len + len_to_bytes(v.len) + v.len > size) { |
| /* header value too large for the buffer */ |
| return 0; |
| } |
| |
| len = hpack_encode_len(out->area, len, v.len); |
| memcpy(out->area + len, v.ptr, v.len); |
| len += v.len; |
| |
| out->data = len; |
| return 1; |
| } |