patches/11-double-bounce.patch

   1 Description: Implement double-bounce handling via an external program.
   2  Implement double-bounce handling via an external program, controlled
   3  by the DBOUNCEPROG config parameter.
   4  Enable this handling by default, using the dbounce-simple-safecat
   5  helper installed by the package.
   6  Unfortunately, Simon Schubert <corecode@dragonflybsd.org> did not
   7  accept this part of my changes to dma in issue 1321.
   8 Origin: other: http://svn.ringlet.net/svn/ringlet/mail/dma/
   9 Bug: http://bugs.dragonflybsd.org/issue1321
  10 Author: Peter Pentchev <roam@ringlet.net>
  11 Last-Update: 2010-07-27
  12
  13 --- a/conf.c
  14 +++ b/conf.c
  15 @@ -256,6 +256,8 @@
  16                         config.authpath= data;
  17                 else if (strcmp(word, "CERTFILE") == 0 && data != NULL)
  18                         config.certfile = data;
  19 +               else if (strcmp(word, "DBOUNCEPROG") == 0 && data != NULL)
  20 +                       config.dbounceprog = data;
  21                 else if (strcmp(word, "MAILNAME") == 0 && data != NULL)
  22                         config.mailname = data;
  23                 else if (strcmp(word, "MAILNAMEFILE") == 0 && data != NULL)
  24 --- a/dma.8
  25 +++ b/dma.8
  26 @@ -240,6 +240,26 @@
  27  .Fl q
  28  option.
  29  This option is handy if you are behind a dialup line.
  30 +.It Ic DBOUNCEPROG Xo
  31 +(string, default=dbounce-simple-safecat)
  32 +.Xc
  33 +Comment if you want the default behavior of
  34 +.Nm
  35 +upon double bounces - just abort the delivery.
  36 +Otherwise, specify the name or full path to a program that will process
  37 +the bounced bounce message.
  38 +.Pp
  39 +The program will be invoked with several command-line options:
  40 +.Pp
  41 +.Nm dbounce
  42 +.Fl t
  43 +.Ar dma
  44 +.Fl a
  45 +.Ar bounced@email.address
  46 +.Fl i
  47 +.Ar queueid
  48 +.Fl f
  49 +.Ar messagefile
  50  .It Ic FULLBOUNCE Xo
  51  (boolean, default=commented)
  52  .Xc
  53 @@ -270,6 +290,7 @@
  54  (e.g.\& user@localhost) so you have to rewrite your outgoing email
  55  address to a valid address.
  56  .Sh SEE ALSO
  57 +.Xr dbounce-simple-safecat 1 ,
  58  .Xr mailaddr 7 ,
  59  .Xr mailwrapper 8 ,
  60  .Xr sendmail 8
  61 --- a/dma.h
  62 +++ b/dma.h
  63 @@ -111,6 +111,7 @@
  64         const char *authpath;
  65         const char *certfile;
  66         int features;
  67 +       const char *dbounceprog;
  68         const char *mailname;
  69         const char *mailnamefile;
  70
  71 --- a/dma.conf
  72 +++ b/dma.conf
  73 @@ -43,6 +43,12 @@
  74  # behind a dialup line.  You have to submit your mails manually with dma -q
  75  #DEFER
  76
  77 +# The double-bounce handler program.  Leave this blank if you like dma's
  78 +# default behavior of simply aborting the delivery, or specify the name or
  79 +# full path to a program that will process the double-bounce message.
  80 +# NOTE: on Debian systems this is handled via debconf!
  81 +DBOUNCEPROG dbounce-simple-safecat
  82 +
  83  # Uncomment if you want the bounce message to include the complete original
  84  # message, not just the headers.
  85  #FULLBOUNCE
  86 --- a/mail.c
  87 +++ b/mail.c
  88 @@ -32,7 +32,12 @@
  89   * SUCH DAMAGE.
  90   */
  91
  92 +#include <sys/types.h>
  93 +#include <sys/wait.h>
  94 +
  95 +#include <err.h>
  96  #include <errno.h>
  97 +#include <signal.h>
  98  #include <syslog.h>
  99  #include <unistd.h>
 100
 101 @@ -43,13 +48,114 @@
 102  {
 103         struct queue bounceq;
 104         char line[1000];
 105 -       size_t pos;
 106         int error;
 107 +       int pipefd[2];
 108 +       pid_t child;
 109 +       char *buf;
 110 +       size_t i, pos, bufsize;
 111 +       ssize_t n;
 112 +       int status;
 113 +       struct sigaction sa;
 114
 115         /* Don't bounce bounced mails */
 116         if (it->sender[0] == 0) {
 117 -               syslog(LOG_INFO, "can not bounce a bounce message, discarding");
 118 -               exit(1);
 119 +               syslog(LOG_INFO, "%s: bounce delivery failed, double-bouncing",
 120 +                      it->queueid);
 121 +               if (config.dbounceprog == NULL) {
 122 +                       syslog(LOG_CRIT, "%s: delivery panic: can't bounce a bounce and no double-bounce program defined in the config file",
 123 +                              it->queueid);
 124 +                       exit(1);
 125 +               }
 126 +               if (pipe(pipefd) == -1) {
 127 +                       syslog(LOG_ERR, "%s: double-bounce: cannot pipe for the double-bounce program: %m",
 128 +                              it->queueid);
 129 +                       exit(1);
 130 +               }
 131 +               bzero(&sa, sizeof(sa));
 132 +               sa.sa_flags = SA_NOCLDSTOP;
 133 +               sa.sa_handler = SIG_DFL;
 134 +               if (sigaction(SIGCHLD, &sa, NULL) == -1) {
 135 +                       syslog(LOG_ERR, "%s: double-bounce: cannot set signal action: %m",
 136 +                              it->queueid);
 137 +                       exit(1);
 138 +               }
 139 +               child = fork();
 140 +               if (child == -1) {
 141 +                       syslog(LOG_ERR, "%s: double-bounce: cannot fork for the double-bounce program: %m",
 142 +                              it->queueid);
 143 +                       exit(1);
 144 +               } else if (child == 0) {
 145 +                       close(pipefd[0]);
 146 +                       dup2(pipefd[1], STDIN_FILENO);
 147 +                       dup2(pipefd[1], STDOUT_FILENO);
 148 +                       dup2(pipefd[1], STDERR_FILENO);
 149 +                       execlp(config.dbounceprog, config.dbounceprog,
 150 +                           "-t", "dma", "-a", it->addr, "-i", it->queueid,
 151 +                           "-f", it->queuefn, NULL);
 152 +                       err(1, "Could not execute %s", config.dbounceprog);
 153 +                       /* NOTREACHED */
 154 +               }
 155 +
 156 +               close(pipefd[1]);
 157 +               buf = NULL;
 158 +               pos = bufsize = 0;
 159 +               while (1) {
 160 +                       if (pos == bufsize) {
 161 +                               char *nbuf;
 162 +                               size_t nsize;
 163 +
 164 +                               nsize = bufsize + BUF_SIZE;
 165 +                               nbuf = realloc(buf, nsize);
 166 +                               if (nbuf == NULL) {
 167 +                                       free(buf);
 168 +                                       syslog(LOG_ERR, "%s: double-bounce failed: could not allocate %lu bytes of memory: %m", it->queueid, (unsigned long)nsize);
 169 +                                       exit(1);
 170 +                               }
 171 +                               buf = nbuf;
 172 +                               bufsize = nsize;
 173 +                       }
 174 +                       n = read(pipefd[0], buf + pos, bufsize - pos);
 175 +                       if (n < 0) {
 176 +                               free(buf);
 177 +                               syslog(LOG_ERR, "%s: double-bounce failed: could not read the output of the double-bounce program: %m", it->queueid);
 178 +                               exit(1);
 179 +                       } else if (n == 0) {
 180 +                               break;
 181 +                       } else {
 182 +                               pos += n;
 183 +                       }
 184 +               }
 185 +               for (i = 0; i < pos; i++)
 186 +                       if (buf[i] < 32)
 187 +                               buf[i] = '_';
 188 +               /*
 189 +                * The order of the reallocation and reading above
 190 +                * guarantees that we have at least one more byte available
 191 +                * in buf[] after pos.
 192 +                */
 193 +               buf[pos] = '\0';
 194 +
 195 +               if (waitpid(child, &status, 0) == -1) {
 196 +                       syslog(LOG_ERR, "%s: double-bounce deferred: could not fetch the result from child process %ld: %m; child process output: %s",
 197 +                              it->queueid, (long)child, buf);
 198 +                       exit(1);
 199 +               } else if (WIFSIGNALED(status)) {
 200 +                       syslog(LOG_ERR, "%s: double-bounce deferred: child process %ld died from signal %d; child process output: %s",
 201 +                              it->queueid, (long)child, WTERMSIG(status), buf);
 202 +                       exit(1);
 203 +               } else if (!WIFEXITED(status)) {
 204 +                       syslog(LOG_ERR, "%s: double-bounce deferred: child process %ld got an unexpected waitpid code of %d; child process output: %s",
 205 +                              it->queueid, (long)child, status, buf);
 206 +                       exit(1);
 207 +               } else if (WEXITSTATUS(status) != 0) {
 208 +                       syslog(LOG_ERR, "%s: double-bounce deferred: child process %ld exited with code %d; child process output: %s",
 209 +                              it->queueid, (long)child, (int)WEXITSTATUS(status), buf);
 210 +                       exit(1);
 211 +               }
 212 +               syslog(LOG_ERR, "%s: double-bounce succeeded, message passed to handler `%s': %s",
 213 +                      it->queueid, config.dbounceprog, buf);
 214 +               delqueue(it);
 215 +               exit(0);
 216         }
 217
 218         bzero(&bounceq, sizeof(bounceq));