/* Copyright 1993-95 by Carl Harris, Jr. Copyright 1996 by Eric S. Raymond * All rights reserved. * For license terms, see the file COPYING in this directory. */ /*********************************************************************** module: fetchmail.c project: fetchmail programmer: Carl Harris, ceharris@mal.com Extensively hacked and improved by esr. description: main driver module for fetchmail ***********************************************************************/ #include #include #if defined(STDC_HEADERS) #include #include #endif #if defined(HAVE_UNISTD_H) #include #endif #include #include #include #include #include #include #include #include #include "fetchmail.h" /* release info */ #define RELEASE_TAG "1.0" #ifdef HAVE_PROTOTYPES /* prototypes for internal functions */ int showoptions (struct hostrec *queryctl); int parseMDAargs (struct hostrec *queryctl); int showversioninfo (void); int dump_options (struct hostrec *queryctl); int query_host(struct hostrec *queryctl); #endif /* controls the detail level of status/progress messages written to stderr */ int outlevel; /* see the O_.* constants above */ int yydebug; /* enable parse debugging */ /* daemon mode control */ int poll_interval; /* poll interval in seconds */ char *logfile; /* log file for daemon mode */ int quitmode; /* if --quit was set */ /* miscellaneous global controls */ char *rcfile; /* path name of rc file */ char *idfile; /* path name of id file */ int linelimit; /* limit # lines retrieved per site */ int versioninfo; /* emit only version info */ /* args for the MDA, parsed out in the usual fashion by parseMDAargs() */ char *mda_argv [32]; /********************************************************************* function: main description: main driver routine arguments: argc argument count as passed by runtime startup code. argv argument strings as passed by runtime startup code. return value: an exit status code for the shell -- see the PS_.* constants defined above. calls: parsecmdline, setdefaults, openuserfolder, doPOP2. globals: none. *********************************************************************/ static void termhook(); static char *lockfile; static int popstatus; static struct hostrec *hostp, *hostlist = (struct hostrec *)NULL; main (argc,argv) int argc; char **argv; { int mboxfd, st, sargc; struct hostrec cmd_opts, def_opts; int parsestatus, implicitmode; char *servername, *user, *tmpdir, tmpbuf[BUFSIZ], *sargv[64]; FILE *tmpfp; pid_t pid; if (setdefaults(&def_opts) != 0) exit(PS_UNDEFINED); if (argc > sizeof(sargv)) exit(PS_SYNTAX); for (sargc = 0; sargc < argc; sargc++) sargv[sargc] = argv[sargc]; if ((parsestatus = parsecmdline(sargc,sargv,&cmd_opts)) < 0) exit(PS_SYNTAX); if (versioninfo) showversioninfo(); if (prc_parse_file(rcfile) != 0) exit(PS_SYNTAX); if (implicitmode = (optind >= sargc)) append_server_names(&sargc, sargv, sizeof(sargv)); /* build in-core data list on all hosts */ while ((servername = getnextserver(sargc,sargv,&parsestatus)) != (char *)0) { if (strcmp(servername, "defaults") == 0) continue; hostp = (struct hostrec *)xmalloc(sizeof(struct hostrec)); prc_mergeoptions(servername, &cmd_opts, &def_opts, hostp); strcpy(hostp->servername, servername); parseMDAargs(hostp); hostp->lastid[0] = '\0'; hostp->next = hostlist; hostlist = hostp; } /* set up to do lock protocol */ if ((tmpdir = getenv("TMPDIR")) == (char *)NULL) tmpdir = "/tmp"; strcpy(tmpbuf, tmpdir); strcat(tmpbuf, "/fetchmail-"); gethostname(tmpbuf + strlen(tmpbuf), HOSTLEN+1); if ((user = getenv("USER")) != (char *)NULL) { strcat(tmpbuf, "-"); strcat(tmpbuf, user); } /* perhaps we just want to check options? */ if (versioninfo) { printf("Taking options from command line and %s\n", rcfile); for (hostp = hostlist; hostp; hostp = hostp->next) { printf("Options for host %s:\n", hostp->servername); dump_params(hostp); if (outlevel == O_VERBOSE) printf(" Lockfile at %s\n", tmpbuf); } if (hostlist == NULL) (void) fprintf(stderr, "No mailservers set up -- perhaps %s is missing?\n", rcfile); exit(0); } else if (hostlist == NULL) { (void) fputs("fetchmail: no mailservers have been specified.\n", stderr); exit(PS_SYNTAX); } if ((lockfile = (char *) malloc(strlen(tmpbuf) + 1)) == NULL) { fprintf(stderr,"fetchmail: cannot allocate memory for lock name.\n"); exit(PS_EXCLUDE); } else (void) strcpy(lockfile, tmpbuf); /* perhaps user asked us to remove a lock */ if (quitmode) { FILE* fp; if ( (fp = fopen(lockfile, "r")) == NULL ) { fprintf(stderr,"fetchmail: no other fetchmail is running\n"); return(PS_EXCLUDE); } fscanf(fp,"%d",&pid); fprintf(stderr,"fetchmail: killing fetchmail at PID %d\n",pid); if ( kill(pid,SIGTERM) < 0 ) fprintf(stderr,"fetchmail: error killing the process %d.\n",pid); else fprintf(stderr,"fetchmail: fetchmail at %d is dead.\n", pid); fclose(fp); remove(lockfile); exit(0); } /* beyond here we don't want more than one fetchmail running per user */ umask(0077); if ( (tmpfp = fopen(lockfile, "r")) != NULL ) { fscanf(tmpfp,"%d",&pid); fprintf(stderr,"Another session appears to be running at pid %d.\nIf you are sure that this is incorrect, remove %s file.\n",pid,lockfile); fclose(tmpfp); return(PS_EXCLUDE); } /* let's get stored message IDs from previous transactions */ if ((st = prc_filecheck(idfile)) != 0) { return (st); } else if ((tmpfp = fopen(idfile, "r")) != (FILE *)NULL) { char buf[POPBUFSIZE+1], host[HOSTLEN+1], id[IDLEN+1]; while (fgets(buf, POPBUFSIZE, tmpfp) != (char *)NULL) { if ((st = sscanf(buf, "%s %s\n", host, id)) == 2) { for (hostp = hostlist; hostp; hostp = hostp->next) { if (strcmp(host, hostp->servername) == 0) strcpy(hostp->lastid, id); } } } fclose(tmpfp); } /* pick up interactively any passwords we need but don't have */ for (hostp = hostlist; hostp; hostp = hostp->next) if (!(implicitmode && hostp->skip) && !hostp->password[0]) { (void) sprintf(tmpbuf, "Enter password for %s@%s: ", hostp->remotename, hostp->servername); (void) strncpy(hostp->password, (char *)getpassword(tmpbuf),PASSWORDLEN-1); } /* * Maybe time to go to demon mode... */ if (poll_interval) daemonize(logfile, termhook); /* if not locked, assert a lock */ signal(SIGABRT, termhook); signal(SIGINT, termhook); signal(SIGTERM, termhook); signal(SIGALRM, termhook); signal(SIGHUP, termhook); signal(SIGPIPE, termhook); signal(SIGQUIT, termhook); if ( (tmpfp = fopen(lockfile,"w")) != NULL ) { fprintf(tmpfp,"%d",getpid()); fclose(tmpfp); } /* * Query all hosts. If there's only one, the error return will * reflect the status of that transaction. */ do { for (hostp = hostlist; hostp; hostp = hostp->next) { if (!implicitmode || !hostp->skip) popstatus = query_host(hostp); } sleep(poll_interval); } while (poll_interval); if (outlevel == O_VERBOSE) fprintf(stderr, "normal termination, status %d\n", popstatus); termhook(0); exit(popstatus); } void termhook(int sig) { FILE *tmpfp; int idcount = 0; if (sig != 0) fprintf(stderr, "terminated with signal %d\n", sig); for (hostp = hostlist; hostp; hostp = hostp->next) { if (hostp->lastid[0]) idcount++; } /* write updated last-seen IDs */ if (!idcount) unlink(idfile); else if ((tmpfp = fopen(idfile, "w")) != (FILE *)NULL) { for (hostp = hostlist; hostp; hostp = hostp->next) { if (hostp->lastid[0]) fprintf(tmpfp, "%s %s\n", hostp->servername, hostp->lastid); } fclose(tmpfp); } unlink(lockfile); exit(popstatus); } /********************************************************************* function: showproto description: protocol index to name mapping arguments: proto protocol index return value: string name of protocol calls: none. globals: none. *********************************************************************/ char *showproto(proto) int proto; { switch (proto) { case P_AUTO: return("auto"); break; case P_POP2: return("POP2"); break; case P_POP3: return("POP3"); break; case P_IMAP: return("IMAP"); break; case P_APOP: return("APOP"); break; case P_RPOP: return("RPOP"); break; default: return("unknown?!?"); break; } } /* * Sequence of protocols to try when autoprobing */ static const int autoprobe[] = {P_POP3, P_IMAP, P_POP2}; int query_host(queryctl) /* perform fetch transaction with single host */ struct hostrec *queryctl; { int i, st; if (outlevel == O_VERBOSE) { time_t now; time(&now); fprintf(stderr, "Querying %s (protocol %s) at %s", queryctl->servername, showproto(queryctl->protocol), ctime(&now)); } switch (queryctl->protocol) { case P_AUTO: for (i = 0; i < sizeof(autoprobe)/sizeof(autoprobe[0]); i++) { queryctl->protocol = autoprobe[i]; if ((st = query_host(queryctl)) == PS_SUCCESS || st == PS_NOMAIL || st == PS_AUTHFAIL) break; } queryctl->protocol = P_AUTO; return(st); break; case P_POP2: return(doPOP2(queryctl)); break; case P_POP3: case P_APOP: case P_RPOP: return(doPOP3(queryctl)); break; case P_IMAP: return(doIMAP(queryctl)); break; default: fprintf(stderr,"fetchmail: unsupported protocol selected.\n"); return(PS_PROTOCOL); } } /********************************************************************* function: showversioninfo description: display program release and compiler info arguments: none. return value: none. calls: none. globals: none. *********************************************************************/ int showversioninfo() { printf("This is fetchmail release %s\n",RELEASE_TAG); } /********************************************************************* function: dump_params description: display program options in English arguments: queryctl merged options return value: none. calls: none. globals: linelimit, outlimit. *********************************************************************/ int dump_params (queryctl) struct hostrec *queryctl; { char *cp; if (queryctl->skip || outlevel == O_VERBOSE) printf(" This host will%s be queried when no host is specified.\n", queryctl->skip ? " not" : ""); printf(" Username = '%s'\n", queryctl->remotename); if (queryctl->password[0] == '\0') printf(" Password will be prompted for.\n"); else if (outlevel == O_VERBOSE) if (queryctl->protocol == P_APOP) printf(" APOP secret = '%s'\n", queryctl->password); else if (queryctl->protocol == P_RPOP) printf(" RPOP secret = '%s'\n", queryctl->password); else printf(" Password = '%s'\n", queryctl->password); printf(" Protocol is %s", showproto(queryctl->protocol)); if (queryctl->port) printf(" (using port %d)", queryctl->port); else if (outlevel == O_VERBOSE) printf(" (using default port)"); putchar('\n'); printf(" Fetched messages will%s be kept on the server (--keep %s).\n", queryctl->keep ? "" : " not", queryctl->keep ? "on" : "off"); printf(" %s messages will be retrieved (--all %s).\n", queryctl->fetchall ? "All" : "Only new", queryctl->fetchall ? "on" : "off"); printf(" Old messages will%s be flushed before message retrieval (--flush %s).\n", queryctl->flush ? "" : " not", queryctl->flush ? "on" : "off"); printf(" Rewrite of server-local addresses is %sabled (--norewrite %s)\n", queryctl->norewrite ? "dis" : "en", queryctl->norewrite ? "on" : "off"); switch(queryctl->output) { case TO_SMTP: printf(" Messages will be SMTP-forwarded to '%s'\n", queryctl->smtphost); break; case TO_FOLDER: printf(" Messages will be appended to '%s'\n", queryctl->userfolder); break; case TO_MDA: printf(" Messages will be delivered with"); for (cp = queryctl->mda; *cp; cp += strlen(cp) + 1) { printf(" %s", cp); } putchar('\n'); break; case TO_STDOUT: printf(" Messages will be dumped to standard output\n"); default: printf(" Message destination unknown?!?\n"); } if (outlevel == O_VERBOSE) { if (queryctl->smtphost[0] != '\0' && queryctl->output != TO_SMTP) printf(" (SMTP host would have been '%s')\n", queryctl->smtphost); if (queryctl->output != TO_FOLDER) printf(" (Mail folder would have been '%s')\n", queryctl->userfolder); if (queryctl->output != TO_MDA) { printf(" (MDA would have been"); for (cp = queryctl->mda; *cp; cp += strlen(cp) + 1) { printf(" %s", cp); } printf(")\n"); } } if (linelimit == 0) printf(" No limit on retrieved message length.\n"); else printf(" Text retrieved per message will be at most %d bytes.\n", linelimit); if (queryctl->lastid[0]) printf(" ID of last message retrieved %s\n", queryctl->lastid); } /********************************************************************* function: openuserfolder description: open the file to which the retrieved messages will be appended. Write-lock the folder if possible. arguments: queryctl fully-determined options (i.e. parsed, defaults invoked, etc). return value: file descriptor for the open file, else -1. calls: none. globals: none. *********************************************************************/ int openuserfolder (queryctl) struct hostrec *queryctl; { int fd; if (queryctl->output == TO_STDOUT) return(1); else /* queryctl->output == TO_FOLDER */ if ((fd = open(queryctl->userfolder,O_CREAT|O_WRONLY|O_APPEND,0600)) >= 0) { #ifdef HAVE_FLOCK if (flock(fd, LOCK_EX) == -1) { close(fd); fd = -1; } #endif /* HAVE_FLOCK */ return(fd); } else { perror("fetchmail: openuserfolder: open()"); return(-1); } } /********************************************************************* function: openmailpipe description: open a one-way pipe to the mail delivery agent. arguments: queryctl fully-determined options (i.e. parsed, defaults invoked, etc). return value: open file descriptor for the pipe or -1. calls: none. globals: reads mda_argv. *********************************************************************/ int openmailpipe (queryctl) struct hostrec *queryctl; { int pipefd [2]; int childpid; char binmailargs [80]; if (pipe(pipefd) < 0) { perror("fetchmail: openmailpipe: pipe"); return(-1); } if ((childpid = fork()) < 0) { perror("fetchmail: openmailpipe: fork"); return(-1); } else if (childpid == 0) { /* in child process space */ close(pipefd[1]); /* close the 'write' end of the pipe */ close(0); /* get rid of inherited stdin */ if (dup(pipefd[0]) != 0) { fputs("fetchmail: openmailpipe: dup() failed\n",stderr); exit(1); } execv(queryctl->mda, mda_argv+1); /* if we got here, an error occurred */ perror("fetchmail: openmailpipe: exec"); return(-1); } /* in the parent process space */ close(pipefd[0]); /* close the 'read' end of the pipe */ return(pipefd[1]); } /********************************************************************* function: closeuserfolder description: close the user-specified mail folder. arguments: fd mail folder descriptor. return value: zero if success else -1. calls: none. globals: none. *********************************************************************/ int closeuserfolder(fd) int fd; { int err; if (fd != 1) { /* not stdout */ err = close(fd); } else err = 0; if (err) perror("fetchmail: closeuserfolder: close"); return(err); } /********************************************************************* function: closemailpipe description: close pipe to the mail delivery agent. arguments: queryctl fully-determined options record fd pipe descriptor. return value: 0 if success, else -1. calls: none. globals: none. *********************************************************************/ int closemailpipe (fd) int fd; { int err; int childpid; if (outlevel == O_VERBOSE) fprintf(stderr, "about to close pipe %d\n", fd); err = close(fd); #if defined(STDC_HEADERS) childpid = wait(NULL); #else childpid = wait((int *) 0); #endif if (err) perror("fetchmail: closemailpipe: close"); if (outlevel == O_VERBOSE) fprintf(stderr, "closed pipe %d\n", fd); return(err); } /********************************************************************* function: parseMDAargs description: parse the argument string given in agent option into a regular *argv[] array. arguments: queryctl fully-determined options record pointer. return value: none. calls: none. globals: writes mda_argv. *********************************************************************/ int parseMDAargs (queryctl) struct hostrec *queryctl; { int argi; char *argp; /* first put the last segment of the MDA pathname in argv[0] */ argp = strrchr(queryctl->mda, '/'); mda_argv[0] = argp ? (argp + 1) : queryctl->mda; argp = queryctl->mda; while (*argp != '\0' && isspace(*argp)) /* skip null first arg */ argp++; /* now punch nulls into the delimiting whitespace in the args */ for (argi = 1; *argp != '\0'; argi++) { mda_argv[argi] = argp; /* store pointer to this argument */ /* find end of this argument */ while (!(*argp == '\0' || isspace(*argp))) argp++; /* punch in a null terminator */ if (*argp != '\0') *(argp++) = '\0'; } mda_argv[argi] = (char *) 0; }