2 * Routines for parsing media type parameters as per RFC 822 and RFC 2045
3 * Copyright 2004, Anders Broman.
4 * Copyright 2004, Olivier Biot.
6 * Refer to the AUTHORS file or the AUTHORS section in the man page
7 * for contacting the author(s) of this file.
9 * Wireshark - Network traffic analyzer
10 * By Gerald Combs <gerald@wireshark.org>
11 * Copyright 1998 Gerald Combs
13 * SPDX-License-Identifier: GPL-2.0-or-later
21 #include <epan/media_params.h>
24 ws_get_next_media_type_parameter(const char *pos, gsize *retnamelen,
25 const char **retvalue, gsize *retvaluelen,
28 const char *p, *namep, *valuep;
32 while ((c = *p) != '\0' && g_ascii_isspace(c))
33 p++; /* Skip white space */
36 /* No more parameters left */
42 /* Look for a '\0' (end of string), '=' (end of parameter name,
43 beginning of parameter value), or ';' (end of parameter). */
44 while ((c = *p) != '\0' && c != '=' && c != ';')
46 *retnamelen = (gsize) (p - namep);
48 /* End of string, so end of parameter, no parameter value */
51 if (retvaluelen != NULL)
57 /* End of parameter, no parameter value */
60 if (retvaluelen != NULL)
65 /* The parameter has a value. Skip the '=' */
70 /* Is the value a quoted string? */
72 /* Yes. Skip the opening quote, and scan forward looking for
73 a non-escaped closing quote. */
78 /* End-of-string. We're done.
79 (XXX - this is an error.) */
80 if (retvaluelen != NULL) {
81 *retvaluelen = (gsize) (p - valuep);
87 /* Closing quote. Skip it; we're done with
93 /* Backslash; this escapes the next character
94 (quoted-pair). Skip the backslash, and make
95 sure there *is* a next character. */
98 /* Nothing left; we're done.
99 (XXX - this is an error.) */
103 /* Skip the character we just processed. */
106 /* Now scan forward looking for a '\0' (end of string)
107 or ';' (end of parameter), in case there's any
108 extra cruft after the quoted-string. */
109 while ((c = *p) != '\0' && c != ';')
112 /* No. Just scan forward looking for a '\0' (end
113 of string) or ';' (end of parameter). */
114 while ((c = *p) != '\0' && c != ';')
118 /* End of string, so end of parameter */
119 if (retvaluelen != NULL) {
120 *retvaluelen = (gsize) (p - valuep);
125 /* End of parameter; point past the terminating ';' */
126 if (retvaluelen != NULL) {
127 *retvaluelen = (gsize) (p - valuep);
134 ws_find_media_type_parameter(wmem_allocator_t *scope, const char *parameters, const char *key)
136 const char *p, *name, *value;
138 gsize keylen, namelen, valuelen;
141 if (parameters == NULL || key == NULL)
142 /* we won't be able to find anything */
145 keylen = (gsize) strlen(key);
147 /* There's no parameter name to searh for */
152 /* There are no parameters in which to search */
157 /* Get the next parameter. */
158 name = ws_get_next_media_type_parameter(p, &namelen, &value,
161 /* No more parameters - not found. */
165 /* Is it the parameter we're looking for? */
166 if (namelen == keylen && g_ascii_strncasecmp(name, key, keylen) == 0) {
173 /* The parameter doesn't have a value. */
177 /* We found the parameter with that name; now extract the value. */
178 valuestr = (char *)wmem_alloc(scope, valuelen + 1);
181 /* Is the value a quoted string? */
183 /* Yes. Skip the opening quote, and scan forward looking for
184 a non-escaped closing quote, copying characters. */
189 /* End-of-string. We're done.
190 (XXX - this is an error.) */
195 /* Closing quote. Skip it; we're done with
196 the quoted-string. */
201 /* Backslash; this escapes the next character
202 (quoted-pair). Skip the backslash, and make
203 sure there *is* a next character. */
206 /* Nothing left; we're done.
207 (XXX - this is an error.) */
211 /* Copy the character. */
215 /* No. Just scan forward until we see a '\0' (end of
216 string or a non-token character, copying characters. */
217 while ((c = *p) != '\0' && g_ascii_isgraph(c) && c != '(' &&
218 c != ')' && c != '<' && c != '>' && c != '@' &&
219 c != ',' && c != ';' && c != ':' && c != '\\' &&
220 c != '"' && c != '/' && c != '[' && c != ']' &&
221 c != '?' && c != '=' && c != '{' && c != '}') {