BSD 4_4 release

[unix-history] / usr / src / libexec / comsat / comsat.c

diff --git a/usr/src/libexec/comsat/comsat.c b/usr/src/libexec/comsat/comsat.c
index b2127c2..e2e4477 100644 (file)
--- a/usr/src/libexec/comsat/comsat.c
+++ b/usr/src/libexec/comsat/comsat.c
@@ -1,213 +1,284 @@
+/*
+ * Copyright (c) 1980, 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. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *     This product includes software developed by the University of
+ *     California, Berkeley and its contributors.
+ * 4. 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.
+ */
+
+#ifndef lint
+static char copyright[] =
+"@(#) Copyright (c) 1980, 1993\n\
+       The Regents of the University of California.  All rights reserved.\n";
+#endif /* not lint */
+

 #ifndef lint
 #ifndef lint

-static char *sccsid = "@(#)comsat.c    4.8 83/07/01";
-#endif
+static char sccsid[] = "@(#)comsat.c   8.1 (Berkeley) 6/4/93";
+#endif /* not lint */

 
 

-#include <sys/types.h>
+#include <sys/param.h>

 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/socket.h>
 #include <sys/stat.h>

+#include <sys/file.h>

 #include <sys/wait.h>
 
 #include <netinet/in.h>
 
 #include <sys/wait.h>
 
 #include <netinet/in.h>
 

-#include <stdio.h>
-#include <sgtty.h>
-#include <utmp.h>
-#include <signal.h>
+#include <ctype.h>

 #include <errno.h>
 #include <netdb.h>
 #include <errno.h>
 #include <netdb.h>

+#include <paths.h>
+#include <pwd.h>
+#include <sgtty.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <utmp.h>

 
 

-/*
- * comsat
- */

 int    debug = 0;
 int    debug = 0;

-#define        dprintf if (debug) printf
+#define        dsyslog if (debug) syslog

 
 

-#define MAXUTMP 100            /* down from init */
+#define MAXIDLE        120

 
 

-struct sockaddr_in sin = { AF_INET };
-extern errno;
+char   hostname[MAXHOSTNAMELEN];
+struct utmp *utmp = NULL;
+time_t lastmsgtime;
+int    nutmp, uf;

 
 

-struct utmp utmp[100];
-int    nutmp;
-int    uf;
-unsigned utmpmtime;                    /* last modification time for utmp */
-int    onalrm();
-struct servent *sp;
-
-#define NAMLEN (sizeof (uts[0].ut_name) + 1)
+void jkfprintf __P((FILE *, char[], off_t));
+void mailfor __P((char *));
+void notify __P((struct utmp *, off_t));
+void onalrm __P((int));
+void reapchildren __P((int));

 
 

+int

 main(argc, argv)
 main(argc, argv)

-char **argv;
+       int argc;
+       char *argv[];

 {
 {

-       register cc;
-       char buf[BUFSIZ];
-       int s;
+       struct sockaddr_in from;
+       register int cc;
+       int fromlen;
+       char msgbuf[100];

 
 

-       sp = getservbyname("biff", "udp");
-       if (sp == 0) {
-               fprintf(stderr, "comsat: biff/udp: unknown service\n");
+       /* verify proper invocation */
+       fromlen = sizeof(from);
+       if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0) {
+               (void)fprintf(stderr,
+                   "comsat: getsockname: %s.\n", strerror(errno));

                exit(1);
        }
                exit(1);
        }

-       if (!debug)
-       if (fork())
-               exit();
-       chdir("/usr/spool/mail");
-       if((uf = open("/etc/utmp",0)) < 0)
-               perror("/etc/utmp"), exit(1);
-       if (!debug)
-       while (fork())
-               wait(0);
-       sleep(10);
-       onalrm();
-       signal(SIGALRM, onalrm);
-       signal(SIGTTOU, SIG_IGN);
-       s = socket(AF_INET, SOCK_DGRAM, 0, 0);
-       if (s < 0) {
-               perror("socket");
+       openlog("comsat", LOG_PID, LOG_DAEMON);
+       if (chdir(_PATH_MAILDIR)) {
+               syslog(LOG_ERR, "chdir: %s: %m", _PATH_MAILDIR);
+               (void) recv(0, msgbuf, sizeof(msgbuf) - 1, 0);

                exit(1);
        }
                exit(1);
        }

-       sin.sin_port = sp->s_port;
-       if (bind(s, &sin, sizeof (sin), 0) < 0) {
-               perror("bind");
+       if ((uf = open(_PATH_UTMP, O_RDONLY, 0)) < 0) {
+               syslog(LOG_ERR, "open: %s: %m", _PATH_UTMP);
+               (void) recv(0, msgbuf, sizeof(msgbuf) - 1, 0);

                exit(1);
        }
                exit(1);
        }

+       (void)time(&lastmsgtime);
+       (void)gethostname(hostname, sizeof(hostname));
+       onalrm(0);
+       (void)signal(SIGALRM, onalrm);
+       (void)signal(SIGTTOU, SIG_IGN);
+       (void)signal(SIGCHLD, reapchildren);

        for (;;) {
        for (;;) {

-               char msgbuf[100];
-               int cc;
-
-               cc = recv(s, msgbuf, sizeof (msgbuf) - 1, 0);
+               cc = recv(0, msgbuf, sizeof(msgbuf) - 1, 0);

                if (cc <= 0) {
                        if (errno != EINTR)
                                sleep(1);
                        errno = 0;
                        continue;
                }
                if (cc <= 0) {
                        if (errno != EINTR)
                                sleep(1);
                        errno = 0;
                        continue;
                }

-               msgbuf[cc] = 0;
+               if (!nutmp)             /* no one has logged in yet */
+                       continue;
+               sigblock(sigmask(SIGALRM));
+               msgbuf[cc] = '\0';
+               (void)time(&lastmsgtime);

                mailfor(msgbuf);
                mailfor(msgbuf);

+               sigsetmask(0L);

        }
 }
 
        }
 }
 

-onalrm()
+void
+reapchildren(signo)
+       int signo;

 {
 {

+       while (wait3(NULL, WNOHANG, NULL) > 0);
+}
+
+void
+onalrm(signo)
+       int signo;
+{
+       static u_int utmpsize;          /* last malloced size for utmp */
+       static u_int utmpmtime;         /* last modification time for utmp */

        struct stat statbf;
        struct stat statbf;

-       struct utmp *utp;

 
 

-       dprintf("alarm\n");
-       alarm(15);
-       fstat(uf,&statbf);
+       if (time(NULL) - lastmsgtime >= MAXIDLE)
+               exit(0);
+       (void)alarm((u_int)15);
+       (void)fstat(uf, &statbf);

        if (statbf.st_mtime > utmpmtime) {
        if (statbf.st_mtime > utmpmtime) {

-               dprintf(" changed\n");

                utmpmtime = statbf.st_mtime;
                utmpmtime = statbf.st_mtime;

-               lseek(uf, 0, 0);
-               nutmp = read(uf,utmp,sizeof(utmp))/sizeof(struct utmp);
-       } else
-               dprintf(" ok\n");
+               if (statbf.st_size > utmpsize) {
+                       utmpsize = statbf.st_size + 10 * sizeof(struct utmp);
+                       if ((utmp = realloc(utmp, utmpsize)) == NULL) {
+                               syslog(LOG_ERR, "%s", strerror(errno));
+                               exit(1);
+                       }
+               }
+               (void)lseek(uf, (off_t)0, L_SET);
+               nutmp = read(uf, utmp, (int)statbf.st_size)/sizeof(struct utmp);
+       }

 }
 
 }
 

+void

 mailfor(name)
        char *name;
 {
        register struct utmp *utp = &utmp[nutmp];
        register char *cp;
 mailfor(name)
        char *name;
 {
        register struct utmp *utp = &utmp[nutmp];
        register char *cp;

-       char *rindex();
-       int offset;
-
-       dprintf("mailfor %s\n", name);
-       cp = name;
-       while (*cp && *cp != '@')
-               cp++;
-       if (*cp == 0) {
-               dprintf("bad format\n");
+       off_t offset;
+
+       if (!(cp = strchr(name, '@')))

                return;
                return;

-       }
-       *cp = 0;
-       offset = atoi(cp+1);
+       *cp = '\0';
+       offset = atoi(cp + 1);

        while (--utp >= utmp)
                if (!strncmp(utp->ut_name, name, sizeof(utmp[0].ut_name)))
        while (--utp >= utmp)
                if (!strncmp(utp->ut_name, name, sizeof(utmp[0].ut_name)))

-                       if (fork() == 0) {
-                               signal(SIGALRM, SIG_DFL);
-                               alarm(30);
-                               notify(utp, offset), exit(0);
-                       } else
-                               while (wait3(0, WNOHANG, 0) > 0)
-                                       continue;
+                       notify(utp, offset);

 }
 
 }
 

-char *cr;
+static char *cr;

 
 

+void

 notify(utp, offset)
        register struct utmp *utp;
 notify(utp, offset)
        register struct utmp *utp;

+       off_t offset;

 {
        FILE *tp;
 {
        FILE *tp;

-       struct sgttyb gttybuf;
-       char tty[20], hostname[32];
-       char name[sizeof (utmp[0].ut_name) + 1];

        struct stat stb;
        struct stat stb;

+       struct sgttyb gttybuf;
+       char tty[20], name[sizeof(utmp[0].ut_name) + 1];

 
 

-       strcpy(tty, "/dev/");
-       strncat(tty, utp->ut_line, sizeof(utp->ut_line));
-       dprintf("notify %s on %s\n", utp->ut_name, tty);
-       if (stat(tty, &stb) == 0 && (stb.st_mode & 0100) == 0) {
-               dprintf("wrong mode\n");
+       (void)snprintf(tty, sizeof(tty), "%s%.*s",
+           _PATH_DEV, (int)sizeof(utp->ut_line), utp->ut_line);
+       if (strchr(tty + sizeof(_PATH_DEV) - 1, '/')) {
+               /* A slash is an attempt to break security... */
+               syslog(LOG_AUTH | LOG_NOTICE, "'/' in \"%s\"", tty);

                return;
        }
                return;
        }

-       if ((tp = fopen(tty,"w")) == 0) {
-               dprintf("fopen failed\n");
+       if (stat(tty, &stb) || !(stb.st_mode & S_IEXEC)) {
+               dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_name, tty);

                return;
        }
                return;
        }

-       ioctl(fileno(tp), TIOCGETP, &gttybuf);
-       cr = (gttybuf.sg_flags & CRMOD) ? "" : "\r";
-       gethostname(hostname, sizeof (hostname));
-       strncpy(name, utp->ut_name, sizeof (utp->ut_name));
-       name[sizeof (name) - 1] = 0;
-       fprintf(tp,"%s\n\007New mail for %s@%s\007 has arrived:%s\n",
-           cr, name, hostname, cr);
-       fprintf(tp,"----%s\n", cr);
+       dsyslog(LOG_DEBUG, "notify %s on %s\n", utp->ut_name, tty);
+       if (fork())
+               return;
+       (void)signal(SIGALRM, SIG_DFL);
+       (void)alarm((u_int)30);
+       if ((tp = fopen(tty, "w")) == NULL) {
+               dsyslog(LOG_ERR, "%s: %s", tty, strerror(errno));
+               _exit(-1);
+       }
+       (void)ioctl(fileno(tp), TIOCGETP, &gttybuf);
+       cr = (gttybuf.sg_flags&CRMOD) && !(gttybuf.sg_flags&RAW) ?
+           "\n" : "\n\r";
+       (void)strncpy(name, utp->ut_name, sizeof(utp->ut_name));
+       name[sizeof(name) - 1] = '\0';
+       (void)fprintf(tp, "%s\007New mail for %s@%.*s\007 has arrived:%s----%s",
+           cr, name, (int)sizeof(hostname), hostname, cr, cr);

        jkfprintf(tp, name, offset);
        jkfprintf(tp, name, offset);

-       fclose(tp);
+       (void)fclose(tp);
+       _exit(0);

 }
 
 }
 

+void

 jkfprintf(tp, name, offset)
        register FILE *tp;
 jkfprintf(tp, name, offset)
        register FILE *tp;

+       char name[];
+       off_t offset;

 {
 {

+       register char *cp, ch;

        register FILE *fi;
        register FILE *fi;

-       register int linecnt, charcnt;
+       register int linecnt, charcnt, inheader;
+       register struct passwd *p;

        char line[BUFSIZ];
 
        char line[BUFSIZ];
 

-       dprintf("HERE %s's mail starting at %d\n",
-           name, offset);
-       if ((fi = fopen(name,"r")) == NULL) {
-               dprintf("Cant read the mail\n");
+       /* Set effective uid to user in case mail drop is on nfs */
+       if ((p = getpwnam(name)) != NULL)
+               (void) setuid(p->pw_uid);
+
+       if ((fi = fopen(name, "r")) == NULL)

                return;
                return;

-       }
-       fseek(fi, offset, 0);
-       /* 
+
+       (void)fseek(fi, offset, L_SET);
+       /*

         * Print the first 7 lines or 560 characters of the new mail
         * (whichever comes first).  Skip header crap other than
         * Print the first 7 lines or 560 characters of the new mail
         * (whichever comes first).  Skip header crap other than

-        * From: and Subject:.
+        * From, Subject, To, and Date.

         */
        linecnt = 7;
        charcnt = 560;
         */
        linecnt = 7;
        charcnt = 560;

-       while (fgets(line, sizeof (line), fi) != NULL) {
-               register char *cp;
-               char *index();
-
-               if (linecnt <= 0 || charcnt <= 0) {  
-                       fprintf(tp,"...more...%s\n", cr);
+       inheader = 1;
+       while (fgets(line, sizeof(line), fi) != NULL) {
+               if (inheader) {
+                       if (line[0] == '\n') {
+                               inheader = 0;
+                               continue;
+                       }
+                       if (line[0] == ' ' || line[0] == '\t' ||
+                           strncmp(line, "From:", 5) &&
+                           strncmp(line, "Subject:", 8))
+                               continue;
+               }
+               if (linecnt <= 0 || charcnt <= 0) {
+                       (void)fprintf(tp, "...more...%s", cr);
+                       (void)fclose(fi);

                        return;
                }
                        return;
                }

-               cp = index(line, ':');
-               if (cp &&
-                   strncmp(line, "Date", cp - line) &&
-                   strncmp(line, "From", cp - line) &&
-                   strncmp(line, "Subject", cp - line) &&
-                   strncmp(line, "To", cp - line))
-                       continue;
-               cp = index(line, '\n');
-               if (cp)
-                       *cp = '\0';
-               fprintf(tp,"%s%s\n", line, cr);
-               linecnt--, charcnt -= strlen(line);
+               /* strip weird stuff so can't trojan horse stupid terminals */
+               for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) {
+                       ch = toascii(ch);
+                       if (!isprint(ch) && !isspace(ch))
+                               ch |= 0x40;
+                       (void)fputc(ch, tp);
+               }
+               (void)fputs(cr, tp);
+               --linecnt;

        }
        }

-       fprintf(tp,"----%s\n", cr);
+       (void)fprintf(tp, "----%s\n", cr);
+       (void)fclose(fi);

 }
 }