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path: root/mailutils/reformime.c (plain)
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1/* vi: set sw=4 ts=4: */
2/*
3 * reformime: parse MIME-encoded message
4 *
5 * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
6 *
7 * Licensed under GPLv2, see file LICENSE in this source tree.
8 */
9//config:config REFORMIME
10//config: bool "reformime"
11//config: default y
12//config: help
13//config: Parse MIME-formatted messages.
14//config:
15//config:config FEATURE_REFORMIME_COMPAT
16//config: bool "Accept and ignore options other than -x and -X"
17//config: default y
18//config: depends on REFORMIME
19//config: help
20//config: Accept (for compatibility only) and ignore options
21//config: other than -x and -X.
22
23//applet:IF_REFORMIME(APPLET(reformime, BB_DIR_BIN, BB_SUID_DROP))
24
25//kbuild:lib-$(CONFIG_REFORMIME) += reformime.o mail.o
26
27#include "libbb.h"
28#include "mail.h"
29
30#if 0
31# define dbg_error_msg(...) bb_error_msg(__VA_ARGS__)
32#else
33# define dbg_error_msg(...) ((void)0)
34#endif
35
36static const char *find_token(const char *const string_array[], const char *key, const char *defvalue)
37{
38 const char *r = NULL;
39 int i;
40 for (i = 0; string_array[i] != NULL; i++) {
41 if (strcasecmp(string_array[i], key) == 0) {
42 r = (char *)string_array[i+1];
43 break;
44 }
45 }
46 return (r) ? r : defvalue;
47}
48
49static const char *xfind_token(const char *const string_array[], const char *key)
50{
51 const char *r = find_token(string_array, key, NULL);
52 if (r)
53 return r;
54 bb_error_msg_and_die("not found: '%s'", key);
55}
56
57enum {
58 OPT_x = 1 << 0,
59 OPT_X = 1 << 1,
60#if ENABLE_FEATURE_REFORMIME_COMPAT
61 OPT_d = 1 << 2,
62 OPT_e = 1 << 3,
63 OPT_i = 1 << 4,
64 OPT_s = 1 << 5,
65 OPT_r = 1 << 6,
66 OPT_c = 1 << 7,
67 OPT_m = 1 << 8,
68 OPT_h = 1 << 9,
69 OPT_o = 1 << 10,
70 OPT_O = 1 << 11,
71#endif
72};
73
74static int parse(const char *boundary, char **argv)
75{
76 int boundary_len = strlen(boundary);
77 char uniq[sizeof("%%llu.%u") + sizeof(int)*3];
78
79 dbg_error_msg("BOUNDARY[%s]", boundary);
80
81 // prepare unique string pattern
82 sprintf(uniq, "%%llu.%u", (unsigned)getpid());
83 dbg_error_msg("UNIQ[%s]", uniq);
84
85 while (1) {
86 char *header;
87 const char *tokens[32]; /* 32 is enough */
88 const char *type;
89
90 /* Read the header (everything up to two \n) */
91 {
92 unsigned header_idx = 0;
93 int last_ch = 0;
94 header = NULL;
95 while (1) {
96 int ch = fgetc(stdin);
97 if (ch == '\r') /* Support both line endings */
98 continue;
99 if (ch == EOF)
100 break;
101 if (ch == '\n' && last_ch == ch)
102 break;
103 if (!(header_idx & 0xff))
104 header = xrealloc(header, header_idx + 0x101);
105 header[header_idx++] = last_ch = ch;
106 }
107 if (!header) {
108 dbg_error_msg("EOF");
109 break;
110 }
111 header[header_idx] = '\0';
112 dbg_error_msg("H:'%s'", p);
113 }
114
115 /* Split to tokens */
116 {
117 char *s, *p;
118 unsigned ntokens;
119 const char *delims = ";=\" \t\n";
120
121 /* Skip to last Content-Type: */
122 s = p = header;
123 while ((p = strchr(p, '\n')) != NULL) {
124 p++;
125 if (strncasecmp(p, "Content-Type:", sizeof("Content-Type:")-1) == 0)
126 s = p;
127 }
128 dbg_error_msg("L:'%s'", p);
129 ntokens = 0;
130 s = strtok(s, delims);
131 while (s) {
132 tokens[ntokens] = s;
133 if (ntokens < ARRAY_SIZE(tokens) - 1)
134 ntokens++;
135 dbg_error_msg("L[%d]='%s'", ntokens, s);
136 s = strtok(NULL, delims);
137 }
138 tokens[ntokens] = NULL;
139 dbg_error_msg("EMPTYLINE, ntokens:%d", ntokens);
140 if (ntokens == 0)
141 break;
142 }
143
144 /* Is it multipart? */
145 type = find_token(tokens, "Content-Type:", "text/plain");
146 dbg_error_msg("TYPE:'%s'", type);
147 if (0 == strncasecmp(type, "multipart/", 10)) {
148 /* Yes, recurse */
149 if (strcasecmp(type + 10, "mixed") != 0)
150 bb_error_msg_and_die("no support of content type '%s'", type);
151 parse(xfind_token(tokens, "boundary"), argv);
152 } else {
153 /* No, process one non-multipart section */
154 char *end;
155 pid_t pid = pid;
156 FILE *fp;
157
158 const char *charset = find_token(tokens, "charset", CONFIG_FEATURE_MIME_CHARSET);
159 const char *encoding = find_token(tokens, "Content-Transfer-Encoding:", "7bit");
160
161 /* Compose target filename */
162 char *filename = (char *)find_token(tokens, "filename", NULL);
163 if (!filename)
164 filename = xasprintf(uniq, monotonic_us());
165 else
166 filename = bb_get_last_path_component_strip(xstrdup(filename));
167
168 if (opts & OPT_X) {
169 int fd[2];
170
171 /* start external helper */
172 xpipe(fd);
173 pid = vfork();
174 if (0 == pid) {
175 /* child reads from fd[0] */
176 close(fd[1]);
177 xmove_fd(fd[0], STDIN_FILENO);
178 xsetenv("CONTENT_TYPE", type);
179 xsetenv("CHARSET", charset);
180 xsetenv("ENCODING", encoding);
181 xsetenv("FILENAME", filename);
182 BB_EXECVP_or_die(argv);
183 }
184 /* parent will write to fd[1] */
185 close(fd[0]);
186 fp = xfdopen_for_write(fd[1]);
187 signal(SIGPIPE, SIG_IGN);
188 } else {
189 /* write to file */
190 char *fname = xasprintf("%s%s", *argv, filename);
191 fp = xfopen_for_write(fname);
192 free(fname);
193 }
194 free(filename);
195
196 /* write to fp */
197 end = NULL;
198 if (0 == strcasecmp(encoding, "base64")) {
199 read_base64(stdin, fp, '-');
200 } else
201 if (0 != strcasecmp(encoding, "7bit")
202 && 0 != strcasecmp(encoding, "8bit")
203 ) {
204 /* quoted-printable, binary, user-defined are unsupported so far */
205 bb_error_msg_and_die("encoding '%s' not supported", encoding);
206 } else {
207 /* plain 7bit or 8bit */
208 while ((end = xmalloc_fgets(stdin)) != NULL) {
209 if ('-' == end[0]
210 && '-' == end[1]
211 && strncmp(end + 2, boundary, boundary_len) == 0
212 ) {
213 break;
214 }
215 fputs(end, fp);
216 }
217 }
218 fclose(fp);
219
220 /* Wait for child */
221 if (opts & OPT_X) {
222 int rc;
223 signal(SIGPIPE, SIG_DFL);
224 rc = (wait4pid(pid) & 0xff);
225 if (rc != 0)
226 return rc + 20;
227 }
228
229 /* Multipart ended? */
230 if (end && '-' == end[2 + boundary_len] && '-' == end[2 + boundary_len + 1]) {
231 dbg_error_msg("FINISHED MPART:'%s'", end);
232 break;
233 }
234 dbg_error_msg("FINISHED:'%s'", end);
235 free(end);
236 } /* end of "handle one non-multipart block" */
237
238 free(header);
239 } /* while (1) */
240
241 dbg_error_msg("ENDPARSE[%s]", boundary);
242
243 return EXIT_SUCCESS;
244}
245
246//usage:#define reformime_trivial_usage
247//usage: "[OPTIONS]"
248//usage:#define reformime_full_usage "\n\n"
249//usage: "Parse MIME-encoded message on stdin\n"
250//usage: "\n -x PREFIX Extract content of MIME sections to files"
251//usage: "\n -X PROG ARGS Filter content of MIME sections through PROG"
252//usage: "\n Must be the last option"
253//usage: "\n"
254//usage: "\nOther options are silently ignored"
255
256/*
257Usage: reformime [options]
258 -d - parse a delivery status notification.
259 -e - extract contents of MIME section.
260 -x - extract MIME section to a file.
261 -X - pipe MIME section to a program.
262 -i - show MIME info.
263 -s n.n.n.n - specify MIME section.
264 -r - rewrite message, filling in missing MIME headers.
265 -r7 - also convert 8bit/raw encoding to quoted-printable, if possible.
266 -r8 - also convert quoted-printable encoding to 8bit, if possible.
267 -c charset - default charset for rewriting, -o, and -O.
268 -m [file] [file]... - create a MIME message digest.
269 -h "header" - decode RFC 2047-encoded header.
270 -o "header" - encode unstructured header using RFC 2047.
271 -O "header" - encode address list header using RFC 2047.
272*/
273
274int reformime_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
275int reformime_main(int argc UNUSED_PARAM, char **argv)
276{
277 const char *opt_prefix = "";
278
279 INIT_G();
280
281 // parse options
282 // N.B. only -x and -X are supported so far
283 opt_complementary = "x--X:X--x";
284 opts = getopt32(argv,
285 "x:X" IF_FEATURE_REFORMIME_COMPAT("deis:r:c:m:*h:o:O:"),
286 &opt_prefix
287 IF_FEATURE_REFORMIME_COMPAT(, NULL, NULL, &G.opt_charset, NULL, NULL, NULL, NULL)
288 );
289 argv += optind;
290
291 return parse("", (opts & OPT_X) ? argv : (char **)&opt_prefix);
292}
293
generated by cgit at 2024-05-15 07:52:32 (GMT)