xref: /lighttpd1.4/src/http_header.c (revision 92e5a021)
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 enum http_header_e http_header_hkey_get_lc(const char * const s, const uint32_t slen) {
76     const struct keyvlenvalue * const kv = http_headers;
77     int i = slen < sizeof(http_headers_off) ? http_headers_off[slen] : -1;
78     if (i < 0) return HTTP_HEADER_OTHER;
79     do {
80         if (0 == memcmp(s, kv[i].value, slen))
81             return (enum http_header_e)kv[i].key;
82     } while (slen == kv[++i].vlen);
83     return HTTP_HEADER_OTHER;
84 }
85 
86 
87 int http_header_str_to_code (const char * const s)
88 {
89     /*(more strict than strtol(); exactly 3 digits followed by SP/TAB/NIL)*/
90     return (light_isdigit(s[0]) && light_isdigit(s[1]) && light_isdigit(s[2])
91             && (s[3] == '\0' || s[3] == ' ' || s[3] == '\t'))
92       ? (s[0]-'0')*100 + (s[1]-'0')*10 + (s[2]-'0')
93       : -1;
94 }
95 
96 int http_header_str_contains_token (const char * const s, const uint32_t slen, const char * const m, const uint32_t mlen)
97 {
98     /*if (slen < mlen) return 0;*//*(possible optimizations for caller)*/
99     /*if (slen == mlen && buffer_eq_icase_ssn(s, m, mlen)) return 1;*/
100     /*(note: does not handle quoted-string)*/
101     uint32_t i = 0;
102     do {
103         while (i < slen &&  (s[i]==' ' || s[i]=='\t' || s[i]==',')) ++i;
104         if (slen - i < mlen) return 0;
105         if (buffer_eq_icase_ssn(s+i, m, mlen)) {
106             i += mlen;
107             if (i == slen || s[i]==' ' || s[i]=='\t' || s[i]==',' || s[i]==';')
108                 return 1;
109         }
110         while (i < slen &&   s[i]!=',') ++i;
111     } while (i < slen);
112     return 0;
113 }
114 
115 
116 int http_header_remove_token (buffer * const b, const char * const m, const uint32_t mlen)
117 {
118     /*(remove all instance of token from string)*/
119     /*(note: does not handle quoted-string)*/
120     int rc = 0;
121     for (char *s = b->ptr; s; ) {
122         while (*s == ' ' || *s == '\t' || *s == ',') ++s;
123         if (0 == strncasecmp(s, m, mlen)) {
124             s += mlen;
125             if (*s=='\0' || *s==' ' || *s=='\t' || *s==',' || *s==';') {
126                 memset(s-mlen, ' ', mlen);
127                 while (*s != '\0' && *s != ',') ++s;
128                 rc = 1;
129                 if (*s == ',') {
130                     *s++ = ' ';
131                     continue;
132                 }
133                 else {
134                     for (s -= mlen; *s != ',' && s != b->ptr; --s) ;
135                     buffer_string_set_length(b, (size_t)(s - b->ptr));
136                     break;
137                 }
138             }
139         }
140         s = strchr(s, ',');
141     }
142     return rc;
143 }
144 
145 
146 static inline void http_header_token_append(buffer * const vb, const char * const v, const uint32_t vlen) {
147     if (!buffer_string_is_empty(vb))
148         buffer_append_string_len(vb, CONST_STR_LEN(", "));
149     buffer_append_string_len(vb, v, vlen);
150 }
151 
152 __attribute_cold__
153 static inline void http_header_token_append_cookie(buffer * const vb, const char * const v, const uint32_t vlen) {
154     /* Cookie request header must be special-cased to use ';' separator
155      * instead of ',' to combine multiple headers (if present) */
156     if (!buffer_string_is_empty(vb))
157         buffer_append_string_len(vb, CONST_STR_LEN("; "));
158     buffer_append_string_len(vb, v, vlen);
159 }
160 
161 __attribute_pure__
162 static inline buffer * http_header_generic_get_ifnotempty(const array * const a, const char * const k, const uint32_t klen) {
163     data_string * const ds =
164       (data_string *)array_get_element_klen(a, k, klen);
165     return ds && !buffer_string_is_empty(&ds->value) ? &ds->value : NULL;
166 }
167 
168 
169 buffer * http_header_response_get(const request_st * const r, enum http_header_e id, const char *k, uint32_t klen) {
170     return (id <= HTTP_HEADER_OTHER || light_btst(r->resp_htags, id))
171       ? http_header_generic_get_ifnotempty(&r->resp_headers, k, klen)
172       : NULL;
173 }
174 
175 void http_header_response_unset(request_st * const r, enum http_header_e id, const char *k, uint32_t klen) {
176     if (id <= HTTP_HEADER_OTHER || light_btst(r->resp_htags, id)) {
177         if (id > HTTP_HEADER_OTHER) light_bclr(r->resp_htags, id);
178         array_set_key_value(&r->resp_headers, k, klen, CONST_STR_LEN(""));
179     }
180 }
181 
182 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) {
183     /* set value, including setting blank value if 0 == vlen
184      * (note: if 0 == vlen, header is still inserted with blank value,
185      *  which is used to indicate a "removed" header)
186      */
187     if (id > HTTP_HEADER_OTHER)
188         (vlen) ? light_bset(r->resp_htags, id) : light_bclr(r->resp_htags, id);
189     array_set_key_value(&r->resp_headers, k, klen, v, vlen);
190 }
191 
192 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) {
193     if (0 == vlen) return;
194     if (id > HTTP_HEADER_OTHER) light_bset(r->resp_htags, id);
195     buffer * const vb = array_get_buf_ptr(&r->resp_headers, k, klen);
196     http_header_token_append(vb, v, vlen);
197 }
198 
199 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) {
200     if (0 == vlen) return;
201     if (id > HTTP_HEADER_OTHER) light_bset(r->resp_htags, id);
202     buffer * const vb = array_get_buf_ptr(&r->resp_headers, k, klen);
203     if (!buffer_string_is_empty(vb)) { /* append value */
204         buffer_append_string_len(vb, CONST_STR_LEN("\r\n"));
205         if (r->http_version >= HTTP_VERSION_2) {
206             r->resp_header_repeated = 1;
207             char * const h = buffer_string_prepare_append(vb, klen + vlen + 2);
208             for (uint32_t i = 0; i < klen; ++i)
209                 h[i] = !light_isupper(k[i]) ? k[i] : (k[i] | 0x20);
210             buffer_commit(vb, klen);
211         }
212         else
213             buffer_append_string_len(vb, k, klen);
214         buffer_append_string_len(vb, CONST_STR_LEN(": "));
215     }
216     buffer_append_string_len(vb, v, vlen);
217 }
218 
219 
220 buffer * http_header_request_get(const request_st * const r, enum http_header_e id, const char *k, uint32_t klen) {
221     return (id <= HTTP_HEADER_OTHER || light_btst(r->rqst_htags, id))
222       ? http_header_generic_get_ifnotempty(&r->rqst_headers, k, klen)
223       : NULL;
224 }
225 
226 void http_header_request_unset(request_st * const r, enum http_header_e id, const char *k, uint32_t klen) {
227     if (id <= HTTP_HEADER_OTHER || light_btst(r->rqst_htags, id)) {
228         if (id > HTTP_HEADER_OTHER) light_bclr(r->rqst_htags, id);
229         array_set_key_value(&r->rqst_headers, k, klen, CONST_STR_LEN(""));
230     }
231 }
232 
233 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) {
234     /* set value, including setting blank value if 0 == vlen
235      * (note: if 0 == vlen, header is still inserted with blank value,
236      *  which is used to indicate a "removed" header)
237      */
238     if (id > HTTP_HEADER_OTHER)
239         (vlen) ? light_bset(r->rqst_htags, id) : light_bclr(r->rqst_htags, id);
240     array_set_key_value(&r->rqst_headers, k, klen, v, vlen);
241 }
242 
243 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) {
244     if (0 == vlen) return;
245     if (id > HTTP_HEADER_OTHER) light_bset(r->rqst_htags, id);
246     buffer * const vb = array_get_buf_ptr(&r->rqst_headers, k, klen);
247     if (id != HTTP_HEADER_COOKIE)
248         http_header_token_append(vb, v, vlen);
249     else
250         http_header_token_append_cookie(vb, v, vlen);
251 }
252 
253 
254 buffer * http_header_env_get(const request_st * const r, const char *k, uint32_t klen) {
255     return http_header_generic_get_ifnotempty(&r->env, k, klen);
256 }
257 
258 void http_header_env_set(request_st * const r, const char *k, uint32_t klen, const char *v, uint32_t vlen) {
259     array_set_key_value(&r->env, k, klen, v, vlen);
260 }
261 
262 void http_header_env_append(request_st * const r, const char *k, uint32_t klen, const char *v, uint32_t vlen) {
263     /*if (0 == vlen) return;*//* skip check; permit env var w/ blank value */
264     buffer * const vb = array_get_buf_ptr(&r->env, k, klen);
265     if (0 == vlen) return;
266     http_header_token_append(vb, v, vlen);
267 }
268 
269 
270 uint32_t
271 http_header_parse_hoff (const char *n, const uint32_t clen, unsigned short hoff[8192])
272 {
273     uint32_t hlen = 0;
274     for (const char *b; (n = memchr((b = n),'\n',clen-hlen)); ++n) {
275         uint32_t x = (uint32_t)(n - b + 1);
276         hlen += x;
277         if (x <= 2 && (x == 1 || n[-1] == '\r')) {
278             hoff[hoff[0]+1] = hlen;
279             return hlen;
280         }
281         if (++hoff[0] >= /*sizeof(hoff)/sizeof(hoff[0])-1*/ 8192-1) break;
282         hoff[hoff[0]] = hlen;
283     }
284     return 0;
285 }
286