busybox/mailutils/reformime.c

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/* vi: set sw=4 ts=4: */
/*
* reformime: parse MIME-encoded message
*
* Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
//config:config REFORMIME
//config: bool "reformime"
//config: default y
//config: help
//config: Parse MIME-formatted messages.
//config:
//config:config FEATURE_REFORMIME_COMPAT
//config: bool "Accept and ignore options other than -x and -X"
//config: default y
//config: depends on REFORMIME
//config: help
//config: Accept (for compatibility only) and ignore options
//config: other than -x and -X.
//applet:IF_REFORMIME(APPLET(reformime, BB_DIR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_REFORMIME) += reformime.o mail.o
#include "libbb.h"
#include "mail.h"
#if 0
# define dbg_error_msg(...) bb_error_msg(__VA_ARGS__)
#else
# define dbg_error_msg(...) ((void)0)
#endif
static const char *find_token(const char *const string_array[], const char *key, const char *defvalue)
{
const char *r = NULL;
int i;
for (i = 0; string_array[i] != NULL; i++) {
if (strcasecmp(string_array[i], key) == 0) {
r = (char *)string_array[i+1];
break;
}
}
return (r) ? r : defvalue;
}
static const char *xfind_token(const char *const string_array[], const char *key)
{
const char *r = find_token(string_array, key, NULL);
if (r)
return r;
bb_error_msg_and_die("not found: '%s'", key);
}
enum {
OPT_x = 1 << 0,
OPT_X = 1 << 1,
#if ENABLE_FEATURE_REFORMIME_COMPAT
OPT_d = 1 << 2,
OPT_e = 1 << 3,
OPT_i = 1 << 4,
OPT_s = 1 << 5,
OPT_r = 1 << 6,
OPT_c = 1 << 7,
OPT_m = 1 << 8,
OPT_h = 1 << 9,
OPT_o = 1 << 10,
OPT_O = 1 << 11,
#endif
};
static int parse(const char *boundary, char **argv)
{
int boundary_len = strlen(boundary);
char uniq[sizeof("%%llu.%u") + sizeof(int)*3];
dbg_error_msg("BOUNDARY[%s]", boundary);
// prepare unique string pattern
sprintf(uniq, "%%llu.%u", (unsigned)getpid());
dbg_error_msg("UNIQ[%s]", uniq);
while (1) {
char *header;
const char *tokens[32]; /* 32 is enough */
const char *type;
/* Read the header (everything up to two \n) */
{
unsigned header_idx = 0;
int last_ch = 0;
header = NULL;
while (1) {
int ch = fgetc(stdin);
if (ch == '\r') /* Support both line endings */
continue;
if (ch == EOF)
break;
if (ch == '\n' && last_ch == ch)
break;
if (!(header_idx & 0xff))
header = xrealloc(header, header_idx + 0x101);
header[header_idx++] = last_ch = ch;
}
if (!header) {
dbg_error_msg("EOF");
break;
}
header[header_idx] = '\0';
dbg_error_msg("H:'%s'", p);
}
/* Split to tokens */
{
char *s, *p;
unsigned ntokens;
const char *delims = ";=\" \t\n";
/* Skip to last Content-Type: */
s = p = header;
while ((p = strchr(p, '\n')) != NULL) {
p++;
if (strncasecmp(p, "Content-Type:", sizeof("Content-Type:")-1) == 0)
s = p;
}
dbg_error_msg("L:'%s'", p);
ntokens = 0;
s = strtok(s, delims);
while (s) {
tokens[ntokens] = s;
if (ntokens < ARRAY_SIZE(tokens) - 1)
ntokens++;
dbg_error_msg("L[%d]='%s'", ntokens, s);
s = strtok(NULL, delims);
}
tokens[ntokens] = NULL;
dbg_error_msg("EMPTYLINE, ntokens:%d", ntokens);
if (ntokens == 0)
break;
}
/* Is it multipart? */
type = find_token(tokens, "Content-Type:", "text/plain");
dbg_error_msg("TYPE:'%s'", type);
if (0 == strncasecmp(type, "multipart/", 10)) {
/* Yes, recurse */
if (strcasecmp(type + 10, "mixed") != 0)
bb_error_msg_and_die("no support of content type '%s'", type);
parse(xfind_token(tokens, "boundary"), argv);
} else {
/* No, process one non-multipart section */
char *end;
pid_t pid = pid;
FILE *fp;
const char *charset = find_token(tokens, "charset", CONFIG_FEATURE_MIME_CHARSET);
const char *encoding = find_token(tokens, "Content-Transfer-Encoding:", "7bit");
/* Compose target filename */
char *filename = (char *)find_token(tokens, "filename", NULL);
if (!filename)
filename = xasprintf(uniq, monotonic_us());
else
filename = bb_get_last_path_component_strip(xstrdup(filename));
if (opts & OPT_X) {
int fd[2];
/* start external helper */
xpipe(fd);
pid = vfork();
if (0 == pid) {
/* child reads from fd[0] */
close(fd[1]);
xmove_fd(fd[0], STDIN_FILENO);
xsetenv("CONTENT_TYPE", type);
xsetenv("CHARSET", charset);
xsetenv("ENCODING", encoding);
xsetenv("FILENAME", filename);
BB_EXECVP_or_die(argv);
}
/* parent will write to fd[1] */
close(fd[0]);
fp = xfdopen_for_write(fd[1]);
signal(SIGPIPE, SIG_IGN);
} else {
/* write to file */
char *fname = xasprintf("%s%s", *argv, filename);
fp = xfopen_for_write(fname);
free(fname);
}
free(filename);
/* write to fp */
end = NULL;
if (0 == strcasecmp(encoding, "base64")) {
read_base64(stdin, fp, '-');
} else
if (0 != strcasecmp(encoding, "7bit")
&& 0 != strcasecmp(encoding, "8bit")
) {
/* quoted-printable, binary, user-defined are unsupported so far */
bb_error_msg_and_die("encoding '%s' not supported", encoding);
} else {
/* plain 7bit or 8bit */
while ((end = xmalloc_fgets(stdin)) != NULL) {
if ('-' == end[0]
&& '-' == end[1]
&& strncmp(end + 2, boundary, boundary_len) == 0
) {
break;
}
fputs(end, fp);
}
}
fclose(fp);
/* Wait for child */
if (opts & OPT_X) {
int rc;
signal(SIGPIPE, SIG_DFL);
rc = (wait4pid(pid) & 0xff);
if (rc != 0)
return rc + 20;
}
/* Multipart ended? */
if (end && '-' == end[2 + boundary_len] && '-' == end[2 + boundary_len + 1]) {
dbg_error_msg("FINISHED MPART:'%s'", end);
break;
}
dbg_error_msg("FINISHED:'%s'", end);
free(end);
} /* end of "handle one non-multipart block" */
free(header);
} /* while (1) */
dbg_error_msg("ENDPARSE[%s]", boundary);
return EXIT_SUCCESS;
}
//usage:#define reformime_trivial_usage
//usage: "[OPTIONS]"
//usage:#define reformime_full_usage "\n\n"
//usage: "Parse MIME-encoded message on stdin\n"
//usage: "\n -x PREFIX Extract content of MIME sections to files"
//usage: "\n -X PROG ARGS Filter content of MIME sections through PROG"
//usage: "\n Must be the last option"
//usage: "\n"
//usage: "\nOther options are silently ignored"
/*
Usage: reformime [options]
-d - parse a delivery status notification.
-e - extract contents of MIME section.
-x - extract MIME section to a file.
-X - pipe MIME section to a program.
-i - show MIME info.
-s n.n.n.n - specify MIME section.
-r - rewrite message, filling in missing MIME headers.
-r7 - also convert 8bit/raw encoding to quoted-printable, if possible.
-r8 - also convert quoted-printable encoding to 8bit, if possible.
-c charset - default charset for rewriting, -o, and -O.
-m [file] [file]... - create a MIME message digest.
-h "header" - decode RFC 2047-encoded header.
-o "header" - encode unstructured header using RFC 2047.
-O "header" - encode address list header using RFC 2047.
*/
int reformime_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int reformime_main(int argc UNUSED_PARAM, char **argv)
{
const char *opt_prefix = "";
INIT_G();
// parse options
// N.B. only -x and -X are supported so far
opt_complementary = "x--X:X--x";
opts = getopt32(argv,
"x:X" IF_FEATURE_REFORMIME_COMPAT("deis:r:c:m:*h:o:O:"),
&opt_prefix
IF_FEATURE_REFORMIME_COMPAT(, NULL, NULL, &G.opt_charset, NULL, NULL, NULL, NULL)
);
argv += optind;
return parse("", (opts & OPT_X) ? argv : (char **)&opt_prefix);
}