release/src/router/busybox/mailutils/mail.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * helper routines
   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 #include "libbb.h"
  10 #include "mail.h"
  11
  12 static void kill_helper(void)
  13 {
  14         if (G.helper_pid > 0) {
  15                 kill(G.helper_pid, SIGTERM);
  16                 G.helper_pid = 0;
  17         }
  18 }
  19
  20 // generic signal handler
  21 static void signal_handler(int signo)
  22 {
  23 #define err signo
  24         if (SIGALRM == signo) {
  25                 kill_helper();
  26                 bb_error_msg_and_die("timed out");
  27         }
  28
  29         // SIGCHLD. reap zombies
  30         if (safe_waitpid(G.helper_pid, &err, WNOHANG) > 0) {
  31                 if (WIFSIGNALED(err))
  32                         bb_error_msg_and_die("helper killed by signal %u", WTERMSIG(err));
  33                 if (WIFEXITED(err)) {
  34                         G.helper_pid = 0;
  35                         if (WEXITSTATUS(err))
  36                                 bb_error_msg_and_die("helper exited (%u)", WEXITSTATUS(err));
  37                 }
  38         }
  39 #undef err
  40 }
  41
  42 void FAST_FUNC launch_helper(const char **argv)
  43 {
  44         // setup vanilla unidirectional pipes interchange
  45         int i;
  46         int pipes[4];
  47
  48         xpipe(pipes);
  49         xpipe(pipes + 2);
  50
  51         // NB: handler must be installed before vfork
  52         bb_signals(0
  53                 + (1 << SIGCHLD)
  54                 + (1 << SIGALRM)
  55                 , signal_handler);
  56
  57         G.helper_pid = xvfork();
  58
  59         i = (!G.helper_pid) * 2; // for parent:0, for child:2
  60         close(pipes[i + 1]);     // 1 or 3 - closing one write end
  61         close(pipes[2 - i]);     // 2 or 0 - closing one read end
  62         xmove_fd(pipes[i], STDIN_FILENO);      // 0 or 2 - using other read end
  63         xmove_fd(pipes[3 - i], STDOUT_FILENO); // 3 or 1 - using other write end
  64         // End result:
  65         // parent stdout [3] -> child stdin [2]
  66         // child stdout [1] -> parent stdin [0]
  67
  68         if (!G.helper_pid) {
  69                 // child: try to execute connection helper
  70                 // NB: SIGCHLD & SIGALRM revert to SIG_DFL on exec
  71                 BB_EXECVP_or_die((char**)argv);
  72         }
  73
  74         // parent
  75         // check whether child is alive
  76         //redundant:signal_handler(SIGCHLD);
  77         // child seems OK -> parent goes on
  78         atexit(kill_helper);
  79 }
  80
  81 char* FAST_FUNC send_mail_command(const char *fmt, const char *param)
  82 {
  83         char *msg;
  84         if (timeout)
  85                 alarm(timeout);
  86         msg = (char*)fmt;
  87         if (fmt) {
  88                 msg = xasprintf(fmt, param);
  89                 if (verbose)
  90                         bb_error_msg("send:'%s'", msg);
  91                 printf("%s\r\n", msg);
  92         }
  93         fflush_all();
  94         return msg;
  95 }
  96
  97 // NB: parse_url can modify url[] (despite const), but only if '@' is there
  98 /*
  99 static char* FAST_FUNC parse_url(char *url, char **user, char **pass)
 100 {
 101         // parse [user[:pass]@]host
 102         // return host
 103         char *s = strchr(url, '@');
 104         *user = *pass = NULL;
 105         if (s) {
 106                 *s++ = '\0';
 107                 *user = url;
 108                 url = s;
 109                 s = strchr(*user, ':');
 110                 if (s) {
 111                         *s++ = '\0';
 112                         *pass = s;
 113                 }
 114         }
 115         return url;
 116 }
 117 */
 118
 119 void FAST_FUNC encode_base64(char *fname, const char *text, const char *eol)
 120 {
 121         enum {
 122                 SRC_BUF_SIZE = 57,  /* This *MUST* be a multiple of 3 */
 123                 DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3),
 124         };
 125 #define src_buf text
 126         char src[SRC_BUF_SIZE];
 127         FILE *fp = fp;
 128         ssize_t len = len;
 129         char dst_buf[DST_BUF_SIZE + 1];
 130
 131         if (fname) {
 132                 fp = (NOT_LONE_DASH(fname)) ? xfopen_for_read(fname) : (FILE *)text;
 133                 src_buf = src;
 134         } else if (text) {
 135                 // though we do not call uuencode(NULL, NULL) explicitly
 136                 // still we do not want to break things suddenly
 137                 len = strlen(text);
 138         } else
 139                 return;
 140
 141         while (1) {
 142                 size_t size;
 143                 if (fname) {
 144                         size = fread((char *)src_buf, 1, SRC_BUF_SIZE, fp);
 145                         if ((ssize_t)size < 0)
 146                                 bb_perror_msg_and_die(bb_msg_read_error);
 147                 } else {
 148                         size = len;
 149                         if (len > SRC_BUF_SIZE)
 150                                 size = SRC_BUF_SIZE;
 151                 }
 152                 if (!size)
 153                         break;
 154                 // encode the buffer we just read in
 155                 bb_uuencode(dst_buf, src_buf, size, bb_uuenc_tbl_base64);
 156                 if (fname) {
 157                         printf("%s\n", eol);
 158                 } else {
 159                         src_buf += size;
 160                         len -= size;
 161                 }
 162                 fwrite(dst_buf, 1, 4 * ((size + 2) / 3), stdout);
 163         }
 164         if (fname && NOT_LONE_DASH(fname))
 165                 fclose(fp);
 166 #undef src_buf
 167 }
 168
 169 /*
 170  * get username and password from a file descriptor
 171  */
 172 void FAST_FUNC get_cred_or_die(int fd)
 173 {
 174         if (isatty(fd)) {
 175                 G.user = xstrdup(bb_ask(fd, /* timeout: */ 0, "User: "));
 176                 G.pass = xstrdup(bb_ask(fd, /* timeout: */ 0, "Password: "));
 177         } else {
 178                 G.user = xmalloc_reads(fd, /* maxsize: */ NULL);
 179                 G.pass = xmalloc_reads(fd, /* maxsize: */ NULL);
 180         }
 181         if (!G.user || !*G.user || !G.pass)
 182                 bb_error_msg_and_die("no username or password");
 183 }