1 /* 2 * Copyright (c) 1980 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #ifndef lint 9 char copyright[] = 10 "@(#) Copyright (c) 1980 Regents of the University of California.\n\ 11 All rights reserved.\n"; 12 #endif /* not lint */ 13 14 #ifndef lint 15 static char sccsid[] = "@(#)comsat.c 5.24 (Berkeley) 02/25/91"; 16 #endif /* not lint */ 17 18 #include <sys/param.h> 19 #include <sys/socket.h> 20 #include <sys/stat.h> 21 #include <sys/file.h> 22 #include <sys/wait.h> 23 24 #include <netinet/in.h> 25 26 #include <stdio.h> 27 #include <sgtty.h> 28 #include <utmp.h> 29 #include <signal.h> 30 #include <errno.h> 31 #include <netdb.h> 32 #include <syslog.h> 33 #include <ctype.h> 34 #include <string.h> 35 #include <paths.h> 36 37 int debug = 0; 38 #define dsyslog if (debug) syslog 39 40 #define MAXIDLE 120 41 42 char hostname[MAXHOSTNAMELEN]; 43 struct utmp *utmp = NULL; 44 time_t lastmsgtime, time(); 45 int nutmp, uf; 46 47 /* ARGSUSED */ 48 main(argc, argv) 49 int argc; 50 char **argv; 51 { 52 extern int errno; 53 register int cc; 54 char msgbuf[100]; 55 struct sockaddr_in from; 56 int fromlen; 57 void onalrm(), reapchildren(); 58 59 /* verify proper invocation */ 60 fromlen = sizeof(from); 61 if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0) { 62 (void)fprintf(stderr, 63 "comsat: getsockname: %s.\n", strerror(errno)); 64 exit(1); 65 } 66 openlog("comsat", LOG_PID, LOG_DAEMON); 67 if (chdir(_PATH_MAILDIR)) { 68 syslog(LOG_ERR, "chdir: %s: %m", _PATH_MAILDIR); 69 exit(1); 70 } 71 if ((uf = open(_PATH_UTMP, O_RDONLY, 0)) < 0) { 72 syslog(LOG_ERR, ".main: %s: %m", _PATH_UTMP); 73 (void) recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 74 exit(1); 75 } 76 (void)time(&lastmsgtime); 77 (void)gethostname(hostname, sizeof(hostname)); 78 onalrm(); 79 (void)signal(SIGALRM, onalrm); 80 (void)signal(SIGTTOU, SIG_IGN); 81 (void)signal(SIGCHLD, reapchildren); 82 for (;;) { 83 cc = recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 84 if (cc <= 0) { 85 if (errno != EINTR) 86 sleep(1); 87 errno = 0; 88 continue; 89 } 90 if (!nutmp) /* no one has logged in yet */ 91 continue; 92 sigblock(sigmask(SIGALRM)); 93 msgbuf[cc] = 0; 94 (void)time(&lastmsgtime); 95 mailfor(msgbuf); 96 sigsetmask(0L); 97 } 98 } 99 100 void 101 reapchildren() 102 { 103 while (wait3((int *)NULL, WNOHANG, (struct rusage *)NULL) > 0); 104 } 105 106 void 107 onalrm() 108 { 109 static u_int utmpsize; /* last malloced size for utmp */ 110 static u_int utmpmtime; /* last modification time for utmp */ 111 struct stat statbf; 112 off_t lseek(); 113 char *malloc(), *realloc(); 114 115 if (time((time_t *)NULL) - lastmsgtime >= MAXIDLE) 116 exit(0); 117 (void)alarm((u_int)15); 118 (void)fstat(uf, &statbf); 119 if (statbf.st_mtime > utmpmtime) { 120 utmpmtime = statbf.st_mtime; 121 if (statbf.st_size > utmpsize) { 122 utmpsize = statbf.st_size + 10 * sizeof(struct utmp); 123 if (utmp) 124 utmp = (struct utmp *)realloc((char *)utmp, utmpsize); 125 else 126 utmp = (struct utmp *)malloc(utmpsize); 127 if (!utmp) { 128 syslog(LOG_ERR, "malloc failed"); 129 exit(1); 130 } 131 } 132 (void)lseek(uf, 0L, L_SET); 133 nutmp = read(uf, utmp, (int)statbf.st_size)/sizeof(struct utmp); 134 } 135 } 136 137 mailfor(name) 138 char *name; 139 { 140 register struct utmp *utp = &utmp[nutmp]; 141 register char *cp; 142 off_t offset; 143 144 if (!(cp = index(name, '@'))) 145 return; 146 *cp = '\0'; 147 offset = atoi(cp + 1); 148 while (--utp >= utmp) 149 if (!strncmp(utp->ut_name, name, sizeof(utmp[0].ut_name))) 150 notify(utp, offset); 151 } 152 153 static char *cr; 154 155 notify(utp, offset) 156 register struct utmp *utp; 157 off_t offset; 158 { 159 static char tty[20] = _PATH_DEV; 160 struct sgttyb gttybuf; 161 struct stat stb; 162 FILE *tp; 163 char name[sizeof(utmp[0].ut_name) + 1]; 164 165 (void)strncpy(tty + sizeof(_PATH_DEV) - 1, utp->ut_line, 166 sizeof(utp->ut_line)); 167 if (stat(tty, &stb) || !(stb.st_mode & S_IEXEC)) { 168 dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_name, tty); 169 return; 170 } 171 dsyslog(LOG_DEBUG, "notify %s on %s\n", utp->ut_name, tty); 172 if (fork()) 173 return; 174 (void)signal(SIGALRM, SIG_DFL); 175 (void)alarm((u_int)30); 176 if ((tp = fopen(tty, "w")) == NULL) { 177 dsyslog(LOG_ERR, "fopen of tty %s failed", tty); 178 _exit(-1); 179 } 180 (void)ioctl(fileno(tp), TIOCGETP, >tybuf); 181 cr = (gttybuf.sg_flags&CRMOD) && !(gttybuf.sg_flags&RAW) ? 182 "\n" : "\n\r"; 183 (void)strncpy(name, utp->ut_name, sizeof(utp->ut_name)); 184 name[sizeof(name) - 1] = '\0'; 185 (void)fprintf(tp, "%s\007New mail for %s@%.*s\007 has arrived:%s----%s", 186 cr, name, sizeof(hostname), hostname, cr, cr); 187 jkfprintf(tp, name, offset); 188 (void)fclose(tp); 189 _exit(0); 190 } 191 192 jkfprintf(tp, name, offset) 193 register FILE *tp; 194 char name[]; 195 off_t offset; 196 { 197 register char *cp, ch; 198 register FILE *fi; 199 register int linecnt, charcnt, inheader; 200 char line[BUFSIZ]; 201 202 if ((fi = fopen(name, "r")) == NULL) 203 return; 204 (void)fseek(fi, offset, L_SET); 205 /* 206 * Print the first 7 lines or 560 characters of the new mail 207 * (whichever comes first). Skip header crap other than 208 * From, Subject, To, and Date. 209 */ 210 linecnt = 7; 211 charcnt = 560; 212 inheader = 1; 213 while (fgets(line, sizeof(line), fi) != NULL) { 214 if (inheader) { 215 if (line[0] == '\n') { 216 inheader = 0; 217 continue; 218 } 219 if (line[0] == ' ' || line[0] == '\t' || 220 strncmp(line, "From:", 5) && 221 strncmp(line, "Subject:", 8)) 222 continue; 223 } 224 if (linecnt <= 0 || charcnt <= 0) { 225 (void)fprintf(tp, "...more...%s", cr); 226 return; 227 } 228 /* strip weird stuff so can't trojan horse stupid terminals */ 229 for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) { 230 ch = toascii(ch); 231 if (!isprint(ch) && !isspace(ch)) 232 ch |= 0x40; 233 (void)fputc(ch, tp); 234 } 235 (void)fputs(cr, tp); 236 --linecnt; 237 } 238 (void)fprintf(tp, "----%s\n", cr); 239 } 240