busybox/mailutils/mail.c
Denys Vlasenko e440b39416 *: stop using atexit in non-debug build: saves ~260 in bss with musl
"builtin" below is atexit's 32-element global array of functions to call.

function                                             old     new   delta
top_main                                             879     889     +10
launch_helper                                        185     193      +8
powertop_main                                       1555    1559      +4
sed_main                                             651     650      -1
slot                                                   4       -      -4
call                                                   4       -      -4
atexit                                                23       -     -23
kill_helper                                           31       -     -31
__funcs_on_exit                                      120       -    -120
__cxa_atexit                                         168       -    -168
builtin                                              260       -    -260
------------------------------------------------------------------------------
(add/remove: 0/8 grow/shrink: 3/1 up/down: 22/-611)          Total: -589 bytes
   text	   data	    bss	    dec	    hex	filename
 912364	    563	   6132	 919059	  e0613	busybox_old
 912035	    563	   5844	 918442	  e03aa	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-08-16 17:45:32 +02:00

175 lines
3.9 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 source tree.
*/
#include <sys/prctl.h>
#include "libbb.h"
#include "mail.h"
// generic signal handler
static void signal_handler(int signo)
{
#define err signo
if (SIGALRM == signo) {
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);
// NB: handler must be installed before vfork
bb_signals(0
+ (1 << SIGCHLD)
+ (1 << SIGALRM)
, signal_handler);
G.helper_pid = xvfork();
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 - using other write end
// End result:
// parent stdout [3] -> child stdin [2]
// child stdout [1] -> parent stdin [0]
if (!G.helper_pid) {
// child
// if parent dies, get SIGTERM
prctl(PR_SET_PDEATHSIG, SIGTERM, 0, 0, 0);
// try to execute connection helper
// NB: SIGCHLD & SIGALRM revert to SIG_DFL on exec
BB_EXECVP_or_die((char**)argv);
}
// parent goes on
}
char* FAST_FUNC send_mail_command(const char *fmt, const char *param)
{
char *msg;
if (timeout)
alarm(timeout);
msg = (char*)fmt;
if (fmt) {
msg = xasprintf(fmt, param);
if (verbose)
bb_error_msg("send:'%s'", msg);
printf("%s\r\n", msg);
}
fflush_all();
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 = 57, /* This *MUST* be a multiple of 3 */
DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3),
};
#define src_buf text
char src[SRC_BUF_SIZE];
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 = src;
} 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) {
puts(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
}
/*
* 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, /* maxsize: */ NULL);
G.pass = xmalloc_reads(fd, /* maxsize: */ NULL);
}
if (!G.user || !*G.user || !G.pass)
bb_error_msg_and_die("no username or password");
}