xref: /lighttpd1.4/src/http_header.c (revision ada09a23)
1 /*
2  * http_header - HTTP header manipulation interfaces
3  *
4  * Copyright(c) 2018 Glenn Strauss gstrauss()gluelogic.com  All rights reserved
5  * License: BSD 3-clause (same as lighttpd)
6  */
7 #include "first.h"
8 
9 #include <string.h>
10 #include "sys-strings.h"
11 
12 #include "http_header.h"
13 #include "base.h"
14 #include "array.h"
15 #include "buffer.h"
16 
17 
18 typedef struct keyvlenvalue {
19     const int key;
20     const uint32_t vlen;
21     const char value[24];
22 } keyvlenvalue;
23 
24 /* Note: must be sorted by length */
25 /* Note: must be kept in sync with http_header.h enum http_header_e */
26 /* Note: must be kept in sync http_headers[] and http_headers_off[] */
27 /* http_headers_off lists first offset at which string of specific len occur */
28 int8_t http_headers_off[] = {
29   -1, -1, -1, -1, 0, 4, 5, 9, 10, 11, 12, -1, 15, 16, 20, 22, 24, 26
30 };
31 static const keyvlenvalue http_headers[] = {
32   { HTTP_HEADER_HOST,                 CONST_LEN_STR("Host") }
33  ,{ HTTP_HEADER_DATE,                 CONST_LEN_STR("Date") }
34  ,{ HTTP_HEADER_ETAG,                 CONST_LEN_STR("ETag") }
35  ,{ HTTP_HEADER_VARY,                 CONST_LEN_STR("Vary") }
36  ,{ HTTP_HEADER_RANGE,                CONST_LEN_STR("Range") }
37  ,{ HTTP_HEADER_COOKIE,               CONST_LEN_STR("Cookie") }
38  ,{ HTTP_HEADER_EXPECT,               CONST_LEN_STR("Expect") }
39  ,{ HTTP_HEADER_STATUS,               CONST_LEN_STR("Status") }
40  ,{ HTTP_HEADER_SERVER,               CONST_LEN_STR("Server") }
41  ,{ HTTP_HEADER_UPGRADE,              CONST_LEN_STR("Upgrade") }
42  ,{ HTTP_HEADER_LOCATION,             CONST_LEN_STR("Location") }
43  ,{ HTTP_HEADER_FORWARDED,            CONST_LEN_STR("Forwarded") }
44  ,{ HTTP_HEADER_CONNECTION,           CONST_LEN_STR("Connection") }
45  ,{ HTTP_HEADER_SET_COOKIE,           CONST_LEN_STR("Set-Cookie") }
46  ,{ HTTP_HEADER_USER_AGENT,           CONST_LEN_STR("User-Agent") }
47  ,{ HTTP_HEADER_CONTENT_TYPE,         CONST_LEN_STR("Content-Type") }
48  ,{ HTTP_HEADER_LAST_MODIFIED,        CONST_LEN_STR("Last-Modified") }
49  ,{ HTTP_HEADER_AUTHORIZATION,        CONST_LEN_STR("Authorization") }
50  ,{ HTTP_HEADER_IF_NONE_MATCH,        CONST_LEN_STR("If-None-Match") }
51  ,{ HTTP_HEADER_CACHE_CONTROL,        CONST_LEN_STR("Cache-Control") }
52  ,{ HTTP_HEADER_CONTENT_LENGTH,       CONST_LEN_STR("Content-Length") }
53  ,{ HTTP_HEADER_HTTP2_SETTINGS,       CONST_LEN_STR("HTTP2-Settings") }
54  ,{ HTTP_HEADER_ACCEPT_ENCODING,      CONST_LEN_STR("Accept-Encoding") }
55  ,{ HTTP_HEADER_X_FORWARDED_FOR,      CONST_LEN_STR("X-Forwarded-For") }
56  ,{ HTTP_HEADER_CONTENT_ENCODING,     CONST_LEN_STR("Content-Encoding") }
57  ,{ HTTP_HEADER_CONTENT_LOCATION,     CONST_LEN_STR("Content-Location") }
58  ,{ HTTP_HEADER_IF_MODIFIED_SINCE,    CONST_LEN_STR("If-Modified-Since") }
59  ,{ HTTP_HEADER_TRANSFER_ENCODING,    CONST_LEN_STR("Transfer-Encoding") }
60  ,{ HTTP_HEADER_X_FORWARDED_PROTO,    CONST_LEN_STR("X-Forwarded-Proto") }
61  ,{ HTTP_HEADER_OTHER, 0, "" }
62 };
63 
64 enum http_header_e http_header_hkey_get(const char * const s, const uint32_t slen) {
65     const struct keyvlenvalue * const kv = http_headers;
66     int i = slen < sizeof(http_headers_off) ? http_headers_off[slen] : -1;
67     if (i < 0) return HTTP_HEADER_OTHER;
68     do {
69         if (buffer_eq_icase_ssn(s, kv[i].value, slen))
70             return (enum http_header_e)kv[i].key;
71     } while (slen == kv[++i].vlen);
72     return HTTP_HEADER_OTHER;
73 }
74 
75 
76 int http_header_str_to_code (const char * const s)
77 {
78     /*(more strict than strtol(); exactly 3 digits followed by SP/TAB/NIL)*/
79     return (light_isdigit(s[0]) && light_isdigit(s[1]) && light_isdigit(s[2])
80             && (s[3] == '\0' || s[3] == ' ' || s[3] == '\t'))
81       ? (s[0]-'0')*100 + (s[1]-'0')*10 + (s[2]-'0')
82       : -1;
83 }
84 
85 int http_header_str_contains_token (const char * const s, const uint32_t slen, const char * const m, const uint32_t mlen)
86 {
87     /*if (slen < mlen) return 0;*//*(possible optimizations for caller)*/
88     /*if (slen == mlen && buffer_eq_icase_ssn(s, m, mlen)) return 1;*/
89     /*(note: does not handle quoted-string)*/
90     uint32_t i = 0;
91     do {
92         while (i < slen &&  (s[i]==' ' || s[i]=='\t' || s[i]==',')) ++i;
93         if (i == slen) return 0;
94         if (buffer_eq_icase_ssn(s+i, m, mlen)) {
95             i += mlen;
96             if (i == slen || s[i]==' ' || s[i]=='\t' || s[i]==',' || s[i]==';')
97                 return 1;
98         }
99         while (i < slen &&   s[i]!=',') ++i;
100     } while (i < slen);
101     return 0;
102 }
103 
104 
105 int http_header_remove_token (buffer * const b, const char * const m, const uint32_t mlen)
106 {
107     /*(remove all instance of token from string)*/
108     /*(note: does not handle quoted-string)*/
109     int rc = 0;
110     for (char *s = b->ptr; s; ) {
111         while (*s == ' ' || *s == '\t' || *s == ',') ++s;
112         if (0 == strncasecmp(s, m, mlen)) {
113             s += mlen;
114             if (*s=='\0' || *s==' ' || *s=='\t' || *s==',' || *s==';') {
115                 memset(s-mlen, ' ', mlen);
116                 while (*s != '\0' && *s != ',') ++s;
117                 rc = 1;
118                 if (*s == ',') {
119                     *s++ = ' ';
120                     continue;
121                 }
122                 else {
123                     for (s -= mlen; *s != ',' && s != b->ptr; --s) ;
124                     buffer_string_set_length(b, (size_t)(s - b->ptr));
125                     break;
126                 }
127             }
128         }
129         s = strchr(s, ',');
130     }
131     return rc;
132 }
133 
134 
135 static inline void http_header_token_append(buffer * const vb, const char * const v, const uint32_t vlen) {
136     if (!buffer_string_is_empty(vb))
137         buffer_append_string_len(vb, CONST_STR_LEN(", "));
138     buffer_append_string_len(vb, v, vlen);
139 }
140 
141 __attribute_pure__
142 static inline buffer * http_header_generic_get_ifnotempty(const array * const a, const char * const k, const uint32_t klen) {
143     data_string * const ds =
144       (data_string *)array_get_element_klen(a, k, klen);
145     return ds && !buffer_string_is_empty(&ds->value) ? &ds->value : NULL;
146 }
147 
148 
149 buffer * http_header_response_get(const request_st * const r, enum http_header_e id, const char *k, uint32_t klen) {
150     return (id <= HTTP_HEADER_OTHER || (r->resp_htags & id))
151       ? http_header_generic_get_ifnotempty(&r->resp_headers, k, klen)
152       : NULL;
153 }
154 
155 void http_header_response_unset(request_st * const r, enum http_header_e id, const char *k, uint32_t klen) {
156     if (id <= HTTP_HEADER_OTHER || (r->resp_htags & id)) {
157         if (id > HTTP_HEADER_OTHER) r->resp_htags &= ~id;
158         array_set_key_value(&r->resp_headers, k, klen, CONST_STR_LEN(""));
159     }
160 }
161 
162 void http_header_response_set(request_st * const r, enum http_header_e id, const char *k, uint32_t klen, const char *v, uint32_t vlen) {
163     /* set value, including setting blank value if 0 == vlen
164      * (note: if 0 == vlen, header is still inserted with blank value,
165      *  which is used to indicate a "removed" header)
166      */
167     if (id > HTTP_HEADER_OTHER)
168         (vlen) ? (r->resp_htags |= id) : (r->resp_htags &= ~id);
169     array_set_key_value(&r->resp_headers, k, klen, v, vlen);
170 }
171 
172 void http_header_response_append(request_st * const r, enum http_header_e id, const char *k, uint32_t klen, const char *v, uint32_t vlen) {
173     if (0 == vlen) return;
174     if (id > HTTP_HEADER_OTHER) r->resp_htags |= id;
175     buffer * const vb = array_get_buf_ptr(&r->resp_headers, k, klen);
176     http_header_token_append(vb, v, vlen);
177 }
178 
179 void http_header_response_insert(request_st * const r, enum http_header_e id, const char *k, uint32_t klen, const char *v, uint32_t vlen) {
180     if (0 == vlen) return;
181     if (id > HTTP_HEADER_OTHER) r->resp_htags |= id;
182     buffer * const vb = array_get_buf_ptr(&r->resp_headers, k, klen);
183     if (!buffer_string_is_empty(vb)) { /* append value */
184         buffer_append_string_len(vb, CONST_STR_LEN("\r\n"));
185         if (r->http_version >= HTTP_VERSION_2) {
186             r->resp_header_repeated = 1;
187             char * const h = buffer_string_prepare_append(vb, klen + vlen + 2);
188             for (uint32_t i = 0; i < klen; ++i)
189                 h[i] = (k[i] < 'A' || k[i] > 'Z') ? k[i] : (k[i] | 0x20);
190             buffer_commit(vb, klen);
191         }
192         else
193             buffer_append_string_len(vb, k, klen);
194         buffer_append_string_len(vb, CONST_STR_LEN(": "));
195     }
196     buffer_append_string_len(vb, v, vlen);
197 }
198 
199 
200 buffer * http_header_request_get(const request_st * const r, enum http_header_e id, const char *k, uint32_t klen) {
201     return (id <= HTTP_HEADER_OTHER || (r->rqst_htags & id))
202       ? http_header_generic_get_ifnotempty(&r->rqst_headers, k, klen)
203       : NULL;
204 }
205 
206 void http_header_request_unset(request_st * const r, enum http_header_e id, const char *k, uint32_t klen) {
207     if (id <= HTTP_HEADER_OTHER || (r->rqst_htags & id)) {
208         if (id > HTTP_HEADER_OTHER) r->rqst_htags &= ~id;
209         array_set_key_value(&r->rqst_headers, k, klen, CONST_STR_LEN(""));
210     }
211 }
212 
213 void http_header_request_set(request_st * const r, enum http_header_e id, const char *k, uint32_t klen, const char *v, uint32_t vlen) {
214     /* set value, including setting blank value if 0 == vlen
215      * (note: if 0 == vlen, header is still inserted with blank value,
216      *  which is used to indicate a "removed" header)
217      */
218     if (id > HTTP_HEADER_OTHER)
219         (vlen) ? (r->rqst_htags |= id) : (r->rqst_htags &= ~id);
220     array_set_key_value(&r->rqst_headers, k, klen, v, vlen);
221 }
222 
223 void http_header_request_append(request_st * const r, enum http_header_e id, const char *k, uint32_t klen, const char *v, uint32_t vlen) {
224     if (0 == vlen) return;
225     if (id > HTTP_HEADER_OTHER) r->rqst_htags |= id;
226     buffer * const vb = array_get_buf_ptr(&r->rqst_headers, k, klen);
227     http_header_token_append(vb, v, vlen);
228 }
229 
230 
231 buffer * http_header_env_get(const request_st * const r, const char *k, uint32_t klen) {
232     return http_header_generic_get_ifnotempty(&r->env, k, klen);
233 }
234 
235 void http_header_env_set(request_st * const r, const char *k, uint32_t klen, const char *v, uint32_t vlen) {
236     array_set_key_value(&r->env, k, klen, v, vlen);
237 }
238 
239 void http_header_env_append(request_st * const r, const char *k, uint32_t klen, const char *v, uint32_t vlen) {
240     /*if (0 == vlen) return;*//* skip check; permit env var w/ blank value */
241     buffer * const vb = array_get_buf_ptr(&r->env, k, klen);
242     if (0 == vlen) return;
243     http_header_token_append(vb, v, vlen);
244 }
245 
246 
247 uint32_t
248 http_header_parse_hoff (const char *n, const uint32_t clen, unsigned short hoff[8192])
249 {
250     uint32_t hlen = 0;
251     for (const char *b; (n = memchr((b = n),'\n',clen-hlen)); ++n) {
252         uint32_t x = (uint32_t)(n - b + 1);
253         hlen += x;
254         if (x <= 2 && (x == 1 || n[-1] == '\r')) {
255             hoff[hoff[0]+1] = hlen;
256             return hlen;
257         }
258         if (++hoff[0] >= /*sizeof(hoff)/sizeof(hoff[0])-1*/ 8192-1) break;
259         hoff[hoff[0]] = hlen;
260     }
261     return 0;
262 }
263