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1 /*
2  * nghttp2 - HTTP/2 C Library
3  *
4  * Copyright (c) 2014 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 #ifdef HAVE_CONFIG_H
26 #  include <config.h>
27 #endif /* !HAVE_CONFIG_H */
28 
29 #include <stdio.h>
30 #include <string.h>
31 
32 #include <nghttp2/nghttp2.h>
33 
34 #define MAKE_NV(K, V)                                                          \
35   {                                                                            \
36     (uint8_t *)K, (uint8_t *)V, sizeof(K) - 1, sizeof(V) - 1,                  \
37         NGHTTP2_NV_FLAG_NONE                                                   \
38   }
39 
40 static void deflate(nghttp2_hd_deflater *deflater,
41                     nghttp2_hd_inflater *inflater, const nghttp2_nv *const nva,
42                     size_t nvlen);
43 
44 static int inflate_header_block(nghttp2_hd_inflater *inflater, uint8_t *in,
45                                 size_t inlen, int final);
46 
main()47 int main() {
48   int rv;
49   nghttp2_hd_deflater *deflater;
50   nghttp2_hd_inflater *inflater;
51   /* Define 1st header set.  This is looks like a HTTP request. */
52   nghttp2_nv nva1[] = {
53       MAKE_NV(":scheme", "https"), MAKE_NV(":authority", "example.org"),
54       MAKE_NV(":path", "/"), MAKE_NV("user-agent", "libnghttp2"),
55       MAKE_NV("accept-encoding", "gzip, deflate")};
56   /* Define 2nd header set */
57   nghttp2_nv nva2[] = {MAKE_NV(":scheme", "https"),
58                        MAKE_NV(":authority", "example.org"),
59                        MAKE_NV(":path", "/stylesheet/style.css"),
60                        MAKE_NV("user-agent", "libnghttp2"),
61                        MAKE_NV("accept-encoding", "gzip, deflate"),
62                        MAKE_NV("referer", "https://example.org")};
63 
64   rv = nghttp2_hd_deflate_new(&deflater, 4096);
65 
66   if (rv != 0) {
67     fprintf(stderr, "nghttp2_hd_deflate_init failed with error: %s\n",
68             nghttp2_strerror(rv));
69     exit(EXIT_FAILURE);
70   }
71 
72   rv = nghttp2_hd_inflate_new(&inflater);
73 
74   if (rv != 0) {
75     fprintf(stderr, "nghttp2_hd_inflate_init failed with error: %s\n",
76             nghttp2_strerror(rv));
77     exit(EXIT_FAILURE);
78   }
79 
80   /* Encode and decode 1st header set */
81   deflate(deflater, inflater, nva1, sizeof(nva1) / sizeof(nva1[0]));
82 
83   /* Encode and decode 2nd header set, using differential encoding
84      using state after encoding 1st header set. */
85   deflate(deflater, inflater, nva2, sizeof(nva2) / sizeof(nva2[0]));
86 
87   nghttp2_hd_inflate_del(inflater);
88   nghttp2_hd_deflate_del(deflater);
89 
90   return 0;
91 }
92 
deflate(nghttp2_hd_deflater * deflater,nghttp2_hd_inflater * inflater,const nghttp2_nv * const nva,size_t nvlen)93 static void deflate(nghttp2_hd_deflater *deflater,
94                     nghttp2_hd_inflater *inflater, const nghttp2_nv *const nva,
95                     size_t nvlen) {
96   ssize_t rv;
97   uint8_t *buf;
98   size_t buflen;
99   size_t outlen;
100   size_t i;
101   size_t sum;
102 
103   sum = 0;
104 
105   for (i = 0; i < nvlen; ++i) {
106     sum += nva[i].namelen + nva[i].valuelen;
107   }
108 
109   printf("Input (%zu byte(s)):\n\n", sum);
110 
111   for (i = 0; i < nvlen; ++i) {
112     fwrite(nva[i].name, 1, nva[i].namelen, stdout);
113     printf(": ");
114     fwrite(nva[i].value, 1, nva[i].valuelen, stdout);
115     printf("\n");
116   }
117 
118   buflen = nghttp2_hd_deflate_bound(deflater, nva, nvlen);
119   buf = malloc(buflen);
120 
121   rv = nghttp2_hd_deflate_hd(deflater, buf, buflen, nva, nvlen);
122 
123   if (rv < 0) {
124     fprintf(stderr, "nghttp2_hd_deflate_hd() failed with error: %s\n",
125             nghttp2_strerror((int)rv));
126 
127     free(buf);
128 
129     exit(EXIT_FAILURE);
130   }
131 
132   outlen = (size_t)rv;
133 
134   printf("\nDeflate (%zu byte(s), ratio %.02f):\n\n", outlen,
135          sum == 0 ? 0 : (double)outlen / (double)sum);
136 
137   for (i = 0; i < outlen; ++i) {
138     if ((i & 0x0fu) == 0) {
139       printf("%08zX: ", i);
140     }
141 
142     printf("%02X ", buf[i]);
143 
144     if (((i + 1) & 0x0fu) == 0) {
145       printf("\n");
146     }
147   }
148 
149   printf("\n\nInflate:\n\n");
150 
151   /* We pass 1 to final parameter, because buf contains whole deflated
152      header data. */
153   rv = inflate_header_block(inflater, buf, outlen, 1);
154 
155   if (rv != 0) {
156     free(buf);
157 
158     exit(EXIT_FAILURE);
159   }
160 
161   printf("\n-----------------------------------------------------------"
162          "--------------------\n");
163 
164   free(buf);
165 }
166 
inflate_header_block(nghttp2_hd_inflater * inflater,uint8_t * in,size_t inlen,int final)167 int inflate_header_block(nghttp2_hd_inflater *inflater, uint8_t *in,
168                          size_t inlen, int final) {
169   ssize_t rv;
170 
171   for (;;) {
172     nghttp2_nv nv;
173     int inflate_flags = 0;
174     size_t proclen;
175 
176     rv = nghttp2_hd_inflate_hd(inflater, &nv, &inflate_flags, in, inlen, final);
177 
178     if (rv < 0) {
179       fprintf(stderr, "inflate failed with error code %zd", rv);
180       return -1;
181     }
182 
183     proclen = (size_t)rv;
184 
185     in += proclen;
186     inlen -= proclen;
187 
188     if (inflate_flags & NGHTTP2_HD_INFLATE_EMIT) {
189       fwrite(nv.name, 1, nv.namelen, stderr);
190       fprintf(stderr, ": ");
191       fwrite(nv.value, 1, nv.valuelen, stderr);
192       fprintf(stderr, "\n");
193     }
194 
195     if (inflate_flags & NGHTTP2_HD_INFLATE_FINAL) {
196       nghttp2_hd_inflate_end_headers(inflater);
197       break;
198     }
199 
200     if ((inflate_flags & NGHTTP2_HD_INFLATE_EMIT) == 0 && inlen == 0) {
201       break;
202     }
203   }
204 
205   return 0;
206 }
207