1 /* Generic support for headers.
2 Copyright (C) 1997, 1998 Free Software Foundation, Inc.
4 This file is part of GNU Wget.
6 GNU Wget is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 GNU Wget is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with Wget; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 In addition, as a special exception, the Free Software Foundation
21 gives permission to link the code of its release of Wget with the
22 OpenSSL project's "OpenSSL" library (or with modified versions of it
23 that use the same license as the "OpenSSL" library), and distribute
24 the linked executables. You must obey the GNU General Public License
25 in all respects for all of the code used other than "OpenSSL". If you
26 modify this file, you may extend this exception to your version of the
27 file, but you are not obligated to do so. If you do not wish to do
28 so, delete this exception statement from your version. */
45 /* This file contains the generic routines for work with headers.
46 Currently they are used only by HTTP in http.c, but they can be
47 used by anything that cares about RFC822-style headers.
49 Header is defined in RFC2068, as quoted below. Note that this
50 definition is not HTTP-specific -- it is virtually
51 indistinguishable from the one given in RFC822 or RFC1036.
53 message-header = field-name ":" [ field-value ] CRLF
56 field-value = *( field-content | LWS )
58 field-content = <the OCTETs making up the field-value
59 and consisting of either *TEXT or combinations
60 of token, tspecials, and quoted-string>
62 The public functions are header_get() and header_process(), which
66 /* Get a header from read-buffer RBUF and return it in *HDR.
68 As defined in RFC2068 and elsewhere, a header can be folded into
69 multiple lines if the continuation line begins with a space or
70 horizontal TAB. Also, this function will accept a header ending
71 with just LF instead of CRLF.
73 The header may be of arbitrary length; the function will allocate
74 as much memory as necessary for it to fit. It need not contain a
75 `:', thus you can use it to retrieve, say, HTTP status line.
77 All trailing whitespace is stripped from the header, and it is
80 header_get (struct rbuf *rbuf, char **hdr, enum header_get_flags flags)
85 *hdr = (char *)xmalloc (bufsize);
89 /* #### Use DO_REALLOC? */
91 *hdr = (char *)xrealloc (*hdr, (bufsize <<= 1));
92 res = RBUF_READCHAR (rbuf, *hdr + i);
95 if ((*hdr)[i] == '\n')
97 if (!((flags & HG_NO_CONTINUATIONS)
99 || (i == 1 && (*hdr)[0] == '\r')))
102 /* If the header is non-empty, we need to check if
103 it continues on to the other line. We do that by
104 peeking at the next character. */
105 res = rbuf_peek (rbuf, &next);
110 /* If the next character is HT or SP, just continue. */
111 if (next == '\t' || next == ' ')
115 /* Strip trailing whitespace. (*hdr)[i] is the newline;
116 decrement I until it points to the last available
118 while (i > 0 && ISSPACE ((*hdr)[i - 1]))
129 DEBUGP (("%s\n", *hdr));
133 /* Check whether HEADER begins with NAME and, if yes, skip the `:' and
134 the whitespace, and call PROCFUN with the arguments of HEADER's
135 contents (after the `:' and space) and ARG. Otherwise, return 0. */
137 header_process (const char *header, const char *name,
138 int (*procfun) (const char *, void *),
141 /* Check whether HEADER matches NAME. */
142 while (*name && (TOLOWER (*name) == TOLOWER (*header)))
144 if (*name || *header++ != ':')
147 header += skip_lws (header);
149 return ((*procfun) (header, arg));
152 /* Helper functions for use with header_process(). */
154 /* Extract a long integer from HEADER and store it to CLOSURE. If an
155 error is encountered, return 0, else 1. */
157 header_extract_number (const char *header, void *closure)
159 const char *p = header;
162 for (result = 0; ISDIGIT (*p); p++)
163 result = 10 * result + (*p - '0');
165 /* Failure if no number present. */
169 /* Skip trailing whitespace. */
172 /* Indicate failure if trailing garbage is present. */
176 *(long *)closure = result;
180 /* Strdup HEADER, and place the pointer to CLOSURE. */
182 header_strdup (const char *header, void *closure)
184 *(char **)closure = xstrdup (header);
188 /* Write the value 1 into the integer pointed to by CLOSURE. */
190 header_exists (const char *header, void *closure)
196 /* Skip LWS (linear white space), if present. Returns number of
197 characters to skip. */
199 skip_lws (const char *string)
201 const char *p = string;
203 while (*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n')