busybox/mailutils/mail.c
Denis Vlasenko 021de3f029 sendmail: document and fix usage of fd #4, fix check for helper failure.
function                                             old     new   delta
packed_usage                                       25663   25694     +31
signal_handler                                       191     215     +24
kill_helper                                           22      31      +9
launch_helper                                        194     184     -10
get_cred_or_die                                      142     129     -13
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/2 up/down: 64/-23)             Total: 41 bytes
2009-03-04 17:56:00 +00:00

246 lines
5.3 KiB
C

/* vi: set sw=4 ts=4: */
/*
* helper routines
*
* Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
*
* Licensed under GPLv2, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
#include "mail.h"
static void kill_helper(void)
{
if (G.helper_pid > 0) {
kill(G.helper_pid, SIGTERM);
G.helper_pid = 0;
}
}
// generic signal handler
static void signal_handler(int signo)
{
#define err signo
if (SIGALRM == signo) {
kill_helper();
bb_error_msg_and_die("timed out");
}
// SIGCHLD. reap zombies
if (safe_waitpid(G.helper_pid, &err, WNOHANG) > 0) {
if (WIFSIGNALED(err))
bb_error_msg_and_die("helper killed by signal %u", WTERMSIG(err));
if (WIFEXITED(err)) {
G.helper_pid = 0;
if (WEXITSTATUS(err))
bb_error_msg_and_die("helper exited (%u)", WEXITSTATUS(err));
}
}
#undef err
}
void FAST_FUNC launch_helper(const char **argv)
{
// setup vanilla unidirectional pipes interchange
int i;
int pipes[4];
xpipe(pipes);
xpipe(pipes + 2);
G.helper_pid = vfork();
if (G.helper_pid < 0)
bb_perror_msg_and_die("vfork");
i = (!G.helper_pid) * 2; // for parent:0, for child:2
close(pipes[i + 1]); // 1 or 3 - closing one write end
close(pipes[2 - i]); // 2 or 0 - closing one read end
xmove_fd(pipes[i], STDIN_FILENO); // 0 or 2 - using other read end
xmove_fd(pipes[3 - i], STDOUT_FILENO); // 3 or 1 - other write end
if (!G.helper_pid) {
// child: try to execute connection helper
BB_EXECVP(*argv, (char **)argv);
_exit(127);
}
// parent
bb_signals(0
+ (1 << SIGCHLD)
+ (1 << SIGALRM)
, signal_handler);
// check whether child is alive
//redundant:signal_handler(SIGCHLD);
// child seems OK -> parent goes on
atexit(kill_helper);
}
const FAST_FUNC char *command(const char *fmt, const char *param)
{
const char *msg = fmt;
if (timeout)
alarm(timeout);
if (msg) {
msg = xasprintf(fmt, param);
printf("%s\r\n", msg);
}
fflush(stdout);
return msg;
}
// NB: parse_url can modify url[] (despite const), but only if '@' is there
/*
static char FAST_FUNC *parse_url(char *url, char **user, char **pass)
{
// parse [user[:pass]@]host
// return host
char *s = strchr(url, '@');
*user = *pass = NULL;
if (s) {
*s++ = '\0';
*user = url;
url = s;
s = strchr(*user, ':');
if (s) {
*s++ = '\0';
*pass = s;
}
}
return url;
}
*/
void FAST_FUNC encode_base64(char *fname, const char *text, const char *eol)
{
enum {
SRC_BUF_SIZE = 45, /* This *MUST* be a multiple of 3 */
DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3),
};
#define src_buf text
FILE *fp = fp;
ssize_t len = len;
char dst_buf[DST_BUF_SIZE + 1];
if (fname) {
fp = (NOT_LONE_DASH(fname)) ? xfopen_for_read(fname) : (FILE *)text;
src_buf = bb_common_bufsiz1;
// N.B. strlen(NULL) segfaults!
} else if (text) {
// though we do not call uuencode(NULL, NULL) explicitly
// still we do not want to break things suddenly
len = strlen(text);
} else
return;
while (1) {
size_t size;
if (fname) {
size = fread((char *)src_buf, 1, SRC_BUF_SIZE, fp);
if ((ssize_t)size < 0)
bb_perror_msg_and_die(bb_msg_read_error);
} else {
size = len;
if (len > SRC_BUF_SIZE)
size = SRC_BUF_SIZE;
}
if (!size)
break;
// encode the buffer we just read in
bb_uuencode(dst_buf, src_buf, size, bb_uuenc_tbl_base64);
if (fname) {
printf("%s\n", eol);
} else {
src_buf += size;
len -= size;
}
fwrite(dst_buf, 1, 4 * ((size + 2) / 3), stdout);
}
if (fname && NOT_LONE_DASH(fname))
fclose(fp);
#undef src_buf
}
void FAST_FUNC decode_base64(FILE *src_stream, FILE *dst_stream)
{
int term_count = 1;
while (1) {
char translated[4];
int count = 0;
while (count < 4) {
char *table_ptr;
int ch;
/* Get next _valid_ character.
* global vector bb_uuenc_tbl_base64[] contains this string:
* "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=\n"
*/
do {
ch = fgetc(src_stream);
if (ch == EOF) {
bb_error_msg_and_die(bb_msg_read_error);
}
// - means end of MIME section
if ('-' == ch) {
// push it back
ungetc(ch, src_stream);
return;
}
table_ptr = strchr(bb_uuenc_tbl_base64, ch);
} while (table_ptr == NULL);
/* Convert encoded character to decimal */
ch = table_ptr - bb_uuenc_tbl_base64;
if (*table_ptr == '=') {
if (term_count == 0) {
translated[count] = '\0';
break;
}
term_count++;
} else if (*table_ptr == '\n') {
/* Check for terminating line */
if (term_count == 5) {
return;
}
term_count = 1;
continue;
} else {
translated[count] = ch;
count++;
term_count = 0;
}
}
/* Merge 6 bit chars to 8 bit */
if (count > 1) {
fputc(translated[0] << 2 | translated[1] >> 4, dst_stream);
}
if (count > 2) {
fputc(translated[1] << 4 | translated[2] >> 2, dst_stream);
}
if (count > 3) {
fputc(translated[2] << 6 | translated[3], dst_stream);
}
}
}
/*
* get username and password from a file descriptor
*/
void FAST_FUNC get_cred_or_die(int fd)
{
if (isatty(fd)) {
G.user = xstrdup(bb_ask(fd, /* timeout: */ 0, "User: "));
G.pass = xstrdup(bb_ask(fd, /* timeout: */ 0, "Password: "));
} else {
G.user = xmalloc_reads(fd, /* pfx: */ NULL, /* maxsize: */ NULL);
G.pass = xmalloc_reads(fd, /* pfx: */ NULL, /* maxsize: */ NULL);
}
if (!G.user || !*G.user || !G.pass)
bb_error_msg_and_die("no username or password");
}