/* $OpenBSD: vacation.c,v 1.36 2015/03/15 00:41:28 millert Exp $ */ /* $NetBSD: vacation.c,v 1.7 1995/04/29 05:58:27 cgd Exp $ */ /* * Copyright (c) 1983, 1987, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* ** Vacation ** Copyright (c) 1983 Eric P. Allman ** Berkeley, California */ #include <sys/stat.h> #include <fcntl.h> #include <pwd.h> #include <db.h> #include <time.h> #include <syslog.h> #include <errno.h> #include <unistd.h> #include <stdio.h> #include <ctype.h> #include <stdlib.h> #include <string.h> #include <paths.h> /* * VACATION -- return a message to the sender when on vacation. * * This program is invoked as a message receiver. It returns a * message specified by the user to whomever sent the mail, taking * care not to return a message too often to prevent "I am on * vacation" loops. */ #define MAXLINE 1024 /* max line from mail header */ #define VDB ".vacation.db" /* dbm's database */ #define VMSG ".vacation.msg" /* vacation message */ typedef struct alias { struct alias *next; char *name; } ALIAS; ALIAS *names; DB *db; char from[MAXLINE]; char subj[MAXLINE]; int junkmail(void); int nsearch(char *, char *); void readheaders(void); int recent(void); void sendmessage(char *); void setinterval(time_t); void setreply(void); void usage(void); #define SECSPERDAY (24 * 60 * 60) int main(int argc, char *argv[]) { int ch, iflag, flags; struct passwd *pw; time_t interval; struct stat sb; ALIAS *cur; opterr = iflag = 0; interval = -1; while ((ch = getopt(argc, argv, "a:Iir:")) != -1) switch ((char)ch) { case 'a': /* alias */ if (!(cur = (ALIAS *)malloc((u_int)sizeof(ALIAS)))) break; cur->name = optarg; cur->next = names; names = cur; break; case 'I': /* backward compatible */ case 'i': /* init the database */ iflag = 1; break; case 'r': if (isdigit((unsigned char)*optarg)) { interval = atol(optarg) * SECSPERDAY; if (interval < 0) usage(); } else interval = 0; /* one time only */ break; default: usage(); } argc -= optind; argv += optind; if (argc != 1) { if (!iflag) usage(); if (!(pw = getpwuid(getuid()))) { syslog(LOG_ERR, "no such user uid %u.", getuid()); exit(1); } } else if (!(pw = getpwnam(*argv))) { syslog(LOG_ERR, "no such user %s.", *argv); exit(1); } if (chdir(pw->pw_dir)) { syslog(LOG_NOTICE, "no such directory %s.", pw->pw_dir); exit(1); } /* * dbopen(3) can not deal with a zero-length file w/o O_TRUNC. */ if (iflag == 1 || (stat(VDB, &sb) == 0 && sb.st_size == (off_t)0)) flags = O_CREAT|O_RDWR|O_TRUNC; else flags = O_CREAT|O_RDWR; db = dbopen(VDB, flags, S_IRUSR|S_IWUSR, DB_HASH, NULL); if (!db) { syslog(LOG_NOTICE, "%s: %m", VDB); exit(1); } if (interval != -1) setinterval(interval); if (iflag) { (void)(db->close)(db); exit(0); } if (!(cur = malloc((u_int)sizeof(ALIAS)))) exit(1); cur->name = pw->pw_name; cur->next = names; names = cur; readheaders(); if (!recent()) { setreply(); (void)(db->close)(db); sendmessage(pw->pw_name); } else (void)(db->close)(db); exit(0); /* NOTREACHED */ } /* * readheaders -- * read mail headers */ void readheaders(void) { char buf[MAXLINE], *p; int tome, cont; ALIAS *cur; cont = tome = 0; while (fgets(buf, sizeof(buf), stdin) && *buf != '\n') switch (*buf) { case 'A': /* "Auto-Submitted:" */ case 'a': cont = 0; if (strncasecmp(buf, "Auto-Submitted:", 15)) break; for (p = buf + 15; isspace((unsigned char)*p); ++p) ; /* * RFC 3834 section 2: * Automatic responses SHOULD NOT be issued in response * to any message which contains an Auto-Submitted * header where the field has any value other than "no". */ if ((p[0] == 'n' || p[0] == 'N') && (p[1] == 'o' || p[1] == 'O')) { for (p += 2; isspace((unsigned char)*p); ++p) ; if (*p == '\0') break; /* Auto-Submitted: no */ } exit(0); case 'F': /* "From " */ case 'f': cont = 0; if (!strncasecmp(buf, "From ", 5)) { for (p = buf + 5; *p && *p != ' '; ++p) ; *p = '\0'; (void)strlcpy(from, buf + 5, sizeof(from)); from[strcspn(from, "\n")] = '\0'; if (junkmail()) exit(0); } break; case 'L': /* "List-Id:" */ case 'l': cont = 0; /* * If present (with any value), message is coming from a * mailing list, cf. RFC2919. */ if (strncasecmp(buf, "List-Id:", 8) == 0) exit(0); break; case 'R': /* "Return-Path:" */ case 'r': cont = 0; if (strncasecmp(buf, "Return-Path:", sizeof("Return-Path:")-1) || (buf[12] != ' ' && buf[12] != '\t')) break; for (p = buf + 12; isspace((unsigned char)*p); ++p) ; if (strlcpy(from, p, sizeof(from)) >= sizeof(from)) { syslog(LOG_NOTICE, "Return-Path %s exceeds limits", p); exit(1); } from[strcspn(from, "\n")] = '\0'; if (junkmail()) exit(0); break; case 'P': /* "Precedence:" */ case 'p': cont = 0; if (strncasecmp(buf, "Precedence:", 11)) break; for (p = buf + 11; isspace((unsigned char)*p); ++p) ; if (!strncasecmp(p, "junk", 4) || !strncasecmp(p, "bulk", 4) || !strncasecmp(p, "list", 4)) exit(0); break; case 'S': /* Subject: */ case 's': cont = 0; if (strncasecmp(buf, "Subject:", sizeof("Subject:")-1) || (buf[8] != ' ' && buf[8] != '\t')) break; for (p = buf + 8; isspace((unsigned char)*p); ++p) ; if (strlcpy(subj, p, sizeof(subj)) >= sizeof(subj)) { syslog(LOG_NOTICE, "Subject %s exceeds limits", p); exit(1); } subj[strcspn(subj, "\n")] = '\0'; break; case 'C': /* "Cc:" */ case 'c': if (strncasecmp(buf, "Cc:", 3)) break; cont = 1; goto findme; case 'T': /* "To:" */ case 't': if (strncasecmp(buf, "To:", 3)) break; cont = 1; goto findme; default: if (!isspace((unsigned char)*buf) || !cont || tome) { cont = 0; break; } findme: for (cur = names; !tome && cur; cur = cur->next) tome += nsearch(cur->name, buf); } if (!tome) exit(0); if (!*from) { syslog(LOG_NOTICE, "no initial \"From\" or \"Return-Path\"line."); exit(1); } } /* * nsearch -- * do a nice, slow, search of a string for a substring. */ int nsearch(char *name, char *str) { int len; for (len = strlen(name); *str; ++str) if (!strncasecmp(name, str, len)) return(1); return(0); } /* * junkmail -- * read the header and return if automagic/junk/bulk/list mail */ int junkmail(void) { static struct ignore { char *name; int len; } ignore[] = { { "-request", 8 }, { "postmaster", 10 }, { "uucp", 4 }, { "mailer-daemon", 13 }, { "mailer", 6 }, { "-relay", 6 }, { NULL, 0 } }; struct ignore *cur; int len; char *p; /* * This is mildly amusing, and I'm not positive it's right; trying * to find the "real" name of the sender, assuming that addresses * will be some variant of: * * From site!site!SENDER%site.domain%site.domain@site.domain */ if (!(p = strchr(from, '%'))) { if (!(p = strchr(from, '@'))) { if ((p = strrchr(from, '!'))) ++p; else p = from; for (; *p; ++p) ; } } len = p - from; for (cur = ignore; cur->name; ++cur) if (len >= cur->len && !strncasecmp(cur->name, p - cur->len, cur->len)) return(1); return(0); } #define VIT "__VACATION__INTERVAL__TIMER__" /* * recent -- * find out if user has gotten a vacation message recently. * use bcopy for machines with alignment restrictions */ int recent(void) { time_t then, next; DBT key, data; /* get interval time */ key.data = VIT; key.size = sizeof(VIT); if ((db->get)(db, &key, &data, 0)) next = SECSPERDAY * 7; else bcopy(data.data, &next, sizeof(next)); /* get record for this address */ key.data = from; key.size = strlen(from); if (!(db->get)(db, &key, &data, 0)) { bcopy(data.data, &then, sizeof(then)); if (next == 0 || then + next > time(NULL)) return(1); } return(0); } /* * setinterval -- * store the reply interval */ void setinterval(time_t interval) { DBT key, data; key.data = VIT; key.size = sizeof(VIT); data.data = &interval; data.size = sizeof(interval); (void)(db->put)(db, &key, &data, 0); } /* * setreply -- * store that this user knows about the vacation. */ void setreply(void) { DBT key, data; time_t now; key.data = from; key.size = strlen(from); (void)time(&now); data.data = &now; data.size = sizeof(now); (void)(db->put)(db, &key, &data, 0); } /* * sendmessage -- * exec sendmail to send the vacation file to sender */ void sendmessage(char *myname) { char buf[MAXLINE]; FILE *mfp, *sfp; int pvect[2], i; mfp = fopen(VMSG, "r"); if (mfp == NULL) { syslog(LOG_NOTICE, "no ~%s/%s file.", myname, VMSG); exit(1); } if (pipe(pvect) < 0) { syslog(LOG_ERR, "pipe: %m"); exit(1); } i = vfork(); if (i < 0) { syslog(LOG_ERR, "fork: %m"); exit(1); } if (i == 0) { dup2(pvect[0], 0); close(pvect[0]); close(pvect[1]); close(fileno(mfp)); execl(_PATH_SENDMAIL, "sendmail", "-f", myname, "--", from, (char *)NULL); syslog(LOG_ERR, "can't exec %s: %m", _PATH_SENDMAIL); _exit(1); } close(pvect[0]); sfp = fdopen(pvect[1], "w"); if (sfp == NULL) { /* XXX could not fdopen; likely out of memory */ fclose(mfp); close(pvect[1]); return; } fprintf(sfp, "To: %s\n", from); fputs("Auto-Submitted: auto-replied\n", sfp); while (fgets(buf, sizeof buf, mfp)) { char *s = strstr(buf, "$SUBJECT"); if (s) { *s = 0; fputs(buf, sfp); fputs(subj, sfp); fputs(s+8, sfp); } else { fputs(buf, sfp); } } fclose(mfp); fclose(sfp); } void usage(void) { syslog(LOG_NOTICE, "uid %u: usage: vacation [-i] [-a alias] login", getuid()); exit(1); }