-p port | The port through which the MTA will connect to the filter. |
-t sec | The timeout value. |
-r addr | A recipient to reject. |
-a addr | A recipient to add. |
#include <sys/types.h> #include <sys/stat.h> #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sysexits.h> #include <unistd.h> #include "libmilter/mfapi.h" #ifndef bool # define bool int # define TRUE 1 # define FALSE 0 #endif /* ! bool */ struct mlfiPriv { char *mlfi_fname; char *mlfi_connectfrom; char *mlfi_helofrom; FILE *mlfi_fp; }; #define MLFIPRIV ((struct mlfiPriv *) smfi_getpriv(ctx)) extern sfsistat mlfi_cleanup(SMFICTX *, bool); /* recipients to add and reject (set with -a and -r options) */ char *add = NULL; char *reject = NULL; sfsistat mlfi_connect(ctx, hostname, hostaddr) SMFICTX *ctx; char *hostname; _SOCK_ADDR *hostaddr; { struct mlfiPriv *priv; char *ident; /* allocate some private memory */ priv = malloc(sizeof *priv); if (priv == NULL) { /* can't accept this message right now */ return SMFIS_TEMPFAIL; } memset(priv, '\0', sizeof *priv); /* save the private data */ smfi_setpriv(ctx, priv); ident = smfi_getsymval(ctx, "_"); if (ident == NULL) ident = "???"; if ((priv->mlfi_connectfrom = strdup(ident)) == NULL) { (void) mlfi_cleanup(ctx, FALSE); return SMFIS_TEMPFAIL; } /* continue processing */ return SMFIS_CONTINUE; } sfsistat mlfi_helo(ctx, helohost) SMFICTX *ctx; char *helohost; { size_t len; char *tls; char *buf; struct mlfiPriv *priv = MLFIPRIV; tls = smfi_getsymval(ctx, "{tls_version}"); if (tls == NULL) tls = "No TLS"; if (helohost == NULL) helohost = "???"; len = strlen(tls) + strlen(helohost) + 3; if ((buf = (char*) malloc(len)) == NULL) { (void) mlfi_cleanup(ctx, FALSE); return SMFIS_TEMPFAIL; } snprintf(buf, len, "%s, %s", helohost, tls); if (priv->mlfi_helofrom != NULL) free(priv->mlfi_helofrom); priv->mlfi_helofrom = buf; /* continue processing */ return SMFIS_CONTINUE; } sfsistat mlfi_envfrom(ctx, argv) SMFICTX *ctx; char **argv; { int fd = -1; int argc = 0; struct mlfiPriv *priv = MLFIPRIV; char *mailaddr = smfi_getsymval(ctx, "{mail_addr}"); /* open a file to store this message */ if ((priv->mlfi_fname = strdup("/tmp/msg.XXXXXX")) == NULL) { (void) mlfi_cleanup(ctx, FALSE); return SMFIS_TEMPFAIL; } if ((fd = mkstemp(priv->mlfi_fname)) == -1) { (void) mlfi_cleanup(ctx, FALSE); return SMFIS_TEMPFAIL; } if ((priv->mlfi_fp = fdopen(fd, "w+")) == NULL) { (void) close(fd); (void) mlfi_cleanup(ctx, FALSE); return SMFIS_TEMPFAIL; } /* count the arguments */ while (*argv++ != NULL) ++argc; /* log the connection information we stored earlier: */ if (fprintf(priv->mlfi_fp, "Connect from %s (%s)\n\n", priv->mlfi_helofrom, priv->mlfi_connectfrom) == EOF) { (void) mlfi_cleanup(ctx, FALSE); return SMFIS_TEMPFAIL; } /* log the sender */ if (fprintf(priv->mlfi_fp, "FROM %s (%d argument%s)\n", mailaddr ? mailaddr : "???", argc, (argc == 1) ? "" : "s") == EOF) { (void) mlfi_cleanup(ctx, FALSE); return SMFIS_TEMPFAIL; } /* continue processing */ return SMFIS_CONTINUE; } sfsistat mlfi_envrcpt(ctx, argv) SMFICTX *ctx; char **argv; { struct mlfiPriv *priv = MLFIPRIV; char *rcptaddr = smfi_getsymval(ctx, "{rcpt_addr}"); int argc = 0; /* count the arguments */ while (*argv++ != NULL) ++argc; /* log this recipient */ if (reject != NULL && rcptaddr != NULL && (strcasecmp(rcptaddr, reject) == 0)) { if (fprintf(priv->mlfi_fp, "RCPT %s -- REJECTED\n", rcptaddr) == EOF) { (void) mlfi_cleanup(ctx, FALSE); return SMFIS_TEMPFAIL; } return SMFIS_REJECT; } if (fprintf(priv->mlfi_fp, "RCPT %s (%d argument%s)\n", rcptaddr ? rcptaddr : "???", argc, (argc == 1) ? "" : "s") == EOF) { (void) mlfi_cleanup(ctx, FALSE); return SMFIS_TEMPFAIL; } /* continue processing */ return SMFIS_CONTINUE; } sfsistat mlfi_header(ctx, headerf, headerv) SMFICTX *ctx; char *headerf; unsigned char *headerv; { /* write the header to the log file */ if (fprintf(MLFIPRIV->mlfi_fp, "%s: %s\n", headerf, headerv) == EOF) { (void) mlfi_cleanup(ctx, FALSE); return SMFIS_TEMPFAIL; } /* continue processing */ return SMFIS_CONTINUE; } sfsistat mlfi_eoh(ctx) SMFICTX *ctx; { /* output the blank line between the header and the body */ if (fprintf(MLFIPRIV->mlfi_fp, "\n") == EOF) { (void) mlfi_cleanup(ctx, FALSE); return SMFIS_TEMPFAIL; } /* continue processing */ return SMFIS_CONTINUE; } sfsistat mlfi_body(ctx, bodyp, bodylen) SMFICTX *ctx; unsigned char *bodyp; size_t bodylen; { struct mlfiPriv *priv = MLFIPRIV; /* output body block to log file */ if (fwrite(bodyp, bodylen, 1, priv->mlfi_fp) != 1) { /* write failed */ fprintf(stderr, "Couldn't write file %s: %s\n", priv->mlfi_fname, strerror(errno)); (void) mlfi_cleanup(ctx, FALSE); return SMFIS_TEMPFAIL; } /* continue processing */ return SMFIS_CONTINUE; } sfsistat mlfi_eom(ctx) SMFICTX *ctx; { bool ok = TRUE; /* change recipients, if requested */ if (add != NULL) ok = (smfi_addrcpt(ctx, add) == MI_SUCCESS); return mlfi_cleanup(ctx, ok); } sfsistat mlfi_abort(ctx) SMFICTX *ctx; { return mlfi_cleanup(ctx, FALSE); } sfsistat mlfi_cleanup(ctx, ok) SMFICTX *ctx; bool ok; { sfsistat rstat = SMFIS_CONTINUE; struct mlfiPriv *priv = MLFIPRIV; char *p; char host[512]; char hbuf[1024]; if (priv == NULL) return rstat; /* close the archive file */ if (priv->mlfi_fp != NULL && fclose(priv->mlfi_fp) == EOF) { /* failed; we have to wait until later */ fprintf(stderr, "Couldn't close archive file %s: %s\n", priv->mlfi_fname, strerror(errno)); rstat = SMFIS_TEMPFAIL; (void) unlink(priv->mlfi_fname); } else if (ok) { /* add a header to the message announcing our presence */ if (gethostname(host, sizeof host) < 0) snprintf(host, sizeof host, "localhost"); p = strrchr(priv->mlfi_fname, '/'); if (p == NULL) p = priv->mlfi_fname; else p++; snprintf(hbuf, sizeof hbuf, "%s@%s", p, host); if (smfi_addheader(ctx, "X-Archived", hbuf) != MI_SUCCESS) { /* failed; we have to wait until later */ fprintf(stderr, "Couldn't add header: X-Archived: %s\n", hbuf); ok = FALSE; rstat = SMFIS_TEMPFAIL; (void) unlink(priv->mlfi_fname); } } else { /* message was aborted -- delete the archive file */ fprintf(stderr, "Message aborted. Removing %s\n", priv->mlfi_fname); rstat = SMFIS_TEMPFAIL; (void) unlink(priv->mlfi_fname); } /* release private memory */ if (priv->mlfi_fname != NULL) free(priv->mlfi_fname); /* return status */ return rstat; } sfsistat mlfi_close(ctx) SMFICTX *ctx; { struct mlfiPriv *priv = MLFIPRIV; if (priv == NULL) return SMFIS_CONTINUE; if (priv->mlfi_connectfrom != NULL) free(priv->mlfi_connectfrom); if (priv->mlfi_helofrom != NULL) free(priv->mlfi_helofrom); free(priv); smfi_setpriv(ctx, NULL); return SMFIS_CONTINUE; } sfsistat mlfi_unknown(ctx, cmd) SMFICTX *ctx; char *cmd; { return SMFIS_CONTINUE; } sfsistat mlfi_data(ctx) SMFICTX *ctx; { return SMFIS_CONTINUE; } sfsistat mlfi_negotiate(ctx, f0, f1, f2, f3, pf0, pf1, pf2, pf3) SMFICTX *ctx; unsigned long f0; unsigned long f1; unsigned long f2; unsigned long f3; unsigned long *pf0; unsigned long *pf1; unsigned long *pf2; unsigned long *pf3; { return SMFIS_ALL_OPTS; } struct smfiDesc smfilter = { "SampleFilter", /* filter name */ SMFI_VERSION, /* version code -- do not change */ SMFIF_ADDHDRS|SMFIF_ADDRCPT, /* flags */ mlfi_connect, /* connection info filter */ mlfi_helo, /* SMTP HELO command filter */ mlfi_envfrom, /* envelope sender filter */ mlfi_envrcpt, /* envelope recipient filter */ mlfi_header, /* header filter */ mlfi_eoh, /* end of header */ mlfi_body, /* body block filter */ mlfi_eom, /* end of message */ mlfi_abort, /* message aborted */ mlfi_close, /* connection cleanup */ mlfi_unknown, /* unknown SMTP commands */ mlfi_data, /* DATA command */ mlfi_negotiate /* Once, at the start of each SMTP connection */ }; static void usage(prog) char *prog; { fprintf(stderr, "Usage: %s -p socket-addr [-t timeout] [-r reject-addr] [-a add-addr]\n", prog); } int main(argc, argv) int argc; char **argv; { bool setconn = FALSE; int c; const char *args = "p:t:r:a:h"; extern char *optarg; /* Process command line options */ while ((c = getopt(argc, argv, args)) != -1) { switch (c) { case 'p': if (optarg == NULL || *optarg == '\0') { (void) fprintf(stderr, "Illegal conn: %s\n", optarg); exit(EX_USAGE); } if (smfi_setconn(optarg) == MI_FAILURE) { (void) fprintf(stderr, "smfi_setconn failed\n"); exit(EX_SOFTWARE); } /* ** If we're using a local socket, make sure it ** doesn't already exist. Don't ever run this ** code as root!! */ if (strncasecmp(optarg, "unix:", 5) == 0) unlink(optarg + 5); else if (strncasecmp(optarg, "local:", 6) == 0) unlink(optarg + 6); setconn = TRUE; break; case 't': if (optarg == NULL || *optarg == '\0') { (void) fprintf(stderr, "Illegal timeout: %s\n", optarg); exit(EX_USAGE); } if (smfi_settimeout(atoi(optarg)) == MI_FAILURE) { (void) fprintf(stderr, "smfi_settimeout failed\n"); exit(EX_SOFTWARE); } break; case 'r': if (optarg == NULL) { (void) fprintf(stderr, "Illegal reject rcpt: %s\n", optarg); exit(EX_USAGE); } reject = optarg; break; case 'a': if (optarg == NULL) { (void) fprintf(stderr, "Illegal add rcpt: %s\n", optarg); exit(EX_USAGE); } add = optarg; smfilter.xxfi_flags |= SMFIF_ADDRCPT; break; case 'h': default: usage(argv[0]); exit(EX_USAGE); } } if (!setconn) { fprintf(stderr, "%s: Missing required -p argument\n", argv[0]); usage(argv[0]); exit(EX_USAGE); } if (smfi_register(smfilter) == MI_FAILURE) { fprintf(stderr, "smfi_register failed\n"); exit(EX_UNAVAILABLE); } return smfi_main(); } /* eof */