Annotation of 43BSD/etc/talkd/announce.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 1983 Regents of the University of California.
        !             3:  * All rights reserved.  The Berkeley software License Agreement
        !             4:  * specifies the terms and conditions for redistribution.
        !             5:  */
        !             6: 
        !             7: #ifndef lint
        !             8: static char sccsid[] = "@(#)announce.c 5.3 (Berkeley) 3/13/86";
        !             9: #endif not lint
        !            10: 
        !            11: #include <sys/types.h>
        !            12: #include <sys/stat.h>
        !            13: #include <sgtty.h>
        !            14: #include <sys/ioctl.h>
        !            15: #include <sys/time.h>
        !            16: #include <stdio.h>
        !            17: #include <sys/wait.h>
        !            18: #include <errno.h>
        !            19: #include <syslog.h>
        !            20: 
        !            21: #include <protocols/talkd.h>
        !            22: 
        !            23: extern int errno;
        !            24: extern char hostname[];
        !            25: 
        !            26: /*
        !            27:  * Announce an invitation to talk.
        !            28:  *
        !            29:  * Because the tty driver insists on attaching a terminal-less
        !            30:  * process to any terminal that it writes on, we must fork a child
        !            31:  * to protect ourselves
        !            32:  */
        !            33: announce(request, remote_machine)
        !            34:        CTL_MSG *request;
        !            35:        char *remote_machine;
        !            36: {
        !            37:        int pid, val, status;
        !            38: 
        !            39:        if (pid = fork()) {
        !            40:                /* we are the parent, so wait for the child */
        !            41:                if (pid == -1)          /* the fork failed */
        !            42:                        return (FAILED);
        !            43:                do {
        !            44:                        val = wait(&status);
        !            45:                        if (val == -1) {
        !            46:                                if (errno == EINTR)
        !            47:                                        continue;
        !            48:                                /* shouldn't happen */
        !            49:                                syslog(LOG_WARNING, "announce: wait: %m");
        !            50:                                return (FAILED);
        !            51:                        }
        !            52:                } while (val != pid);
        !            53:                if (status&0377 > 0)    /* we were killed by some signal */
        !            54:                        return (FAILED);
        !            55:                /* Get the second byte, this is the exit/return code */
        !            56:                return ((status >> 8) & 0377);
        !            57:        }
        !            58:        /* we are the child, go and do it */
        !            59:        _exit(announce_proc(request, remote_machine));
        !            60: }
        !            61:        
        !            62: /*
        !            63:  * See if the user is accepting messages. If so, announce that 
        !            64:  * a talk is requested.
        !            65:  */
        !            66: announce_proc(request, remote_machine)
        !            67:        CTL_MSG *request;
        !            68:        char *remote_machine;
        !            69: {
        !            70:        int pid, status;
        !            71:        char full_tty[32];
        !            72:        FILE *tf;
        !            73:        struct stat stbuf;
        !            74: 
        !            75:        sprintf(full_tty, "/dev/%s", request->r_tty);
        !            76:        if (access(full_tty, 0) != 0)
        !            77:                return (FAILED);
        !            78:        if ((tf = fopen(full_tty, "w")) == NULL)
        !            79:                return (PERMISSION_DENIED);
        !            80:        /*
        !            81:         * On first tty open, the server will have
        !            82:         * it's pgrp set, so disconnect us from the
        !            83:         * tty before we catch a signal.
        !            84:         */
        !            85:        ioctl(fileno(tf), TIOCNOTTY, (struct sgttyb *) 0);
        !            86:        if (fstat(fileno(tf), &stbuf) < 0)
        !            87:                return (PERMISSION_DENIED);
        !            88:        if ((stbuf.st_mode&020) == 0)
        !            89:                return (PERMISSION_DENIED);
        !            90:        print_mesg(tf, request, remote_machine);
        !            91:        fclose(tf);
        !            92:        return (SUCCESS);
        !            93: }
        !            94: 
        !            95: #define max(a,b) ( (a) > (b) ? (a) : (b) )
        !            96: #define N_LINES 5
        !            97: #define N_CHARS 120
        !            98: 
        !            99: /*
        !           100:  * Build a block of characters containing the message. 
        !           101:  * It is sent blank filled and in a single block to
        !           102:  * try to keep the message in one piece if the recipient
        !           103:  * in in vi at the time
        !           104:  */
        !           105: print_mesg(tf, request, remote_machine)
        !           106:        FILE *tf;
        !           107:        CTL_MSG *request;
        !           108:        char *remote_machine;
        !           109: {
        !           110:        struct timeval clock;
        !           111:        struct timezone zone;
        !           112:        struct tm *localtime();
        !           113:        struct tm *localclock;
        !           114:        char line_buf[N_LINES][N_CHARS];
        !           115:        int sizes[N_LINES];
        !           116:        char big_buf[N_LINES*N_CHARS];
        !           117:        char *bptr, *lptr;
        !           118:        int i, j, max_size;
        !           119: 
        !           120:        i = 0;
        !           121:        max_size = 0;
        !           122:        gettimeofday(&clock, &zone);
        !           123:        localclock = localtime( &clock.tv_sec );
        !           124:        sprintf(line_buf[i], " ");
        !           125:        sizes[i] = strlen(line_buf[i]);
        !           126:        max_size = max(max_size, sizes[i]);
        !           127:        i++;
        !           128:        sprintf(line_buf[i], "Message from Talk_Daemon@%s at %d:%02d ...",
        !           129:        hostname, localclock->tm_hour , localclock->tm_min );
        !           130:        sizes[i] = strlen(line_buf[i]);
        !           131:        max_size = max(max_size, sizes[i]);
        !           132:        i++;
        !           133:        sprintf(line_buf[i], "talk: connection requested by %s@%s.",
        !           134:                request->l_name, remote_machine);
        !           135:        sizes[i] = strlen(line_buf[i]);
        !           136:        max_size = max(max_size, sizes[i]);
        !           137:        i++;
        !           138:        sprintf(line_buf[i], "talk: respond with:  talk %s@%s",
        !           139:                request->l_name, remote_machine);
        !           140:        sizes[i] = strlen(line_buf[i]);
        !           141:        max_size = max(max_size, sizes[i]);
        !           142:        i++;
        !           143:        sprintf(line_buf[i], " ");
        !           144:        sizes[i] = strlen(line_buf[i]);
        !           145:        max_size = max(max_size, sizes[i]);
        !           146:        i++;
        !           147:        bptr = big_buf;
        !           148:        *bptr++ = ''; /* send something to wake them up */
        !           149:        *bptr++ = '\r'; /* add a \r in case of raw mode */
        !           150:        *bptr++ = '\n';
        !           151:        for (i = 0; i < N_LINES; i++) {
        !           152:                /* copy the line into the big buffer */
        !           153:                lptr = line_buf[i];
        !           154:                while (*lptr != '\0')
        !           155:                        *(bptr++) = *(lptr++);
        !           156:                /* pad out the rest of the lines with blanks */
        !           157:                for (j = sizes[i]; j < max_size + 2; j++)
        !           158:                        *(bptr++) = ' ';
        !           159:                *(bptr++) = '\r';       /* add a \r in case of raw mode */
        !           160:                *(bptr++) = '\n';
        !           161:        }
        !           162:        *bptr = '\0';
        !           163:        fprintf(tf, big_buf);
        !           164:        fflush(tf);
        !           165:        ioctl(fileno(tf), TIOCNOTTY, (struct sgttyb *) 0);
        !           166: }

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