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Annotation of 42BSD/ucb/talk/announce.c, revision 1.1

1.1     ! root        1: /* $Header: /a/guest/moore/talk/RCS/announce.c,v 1.8 83/07/06 00:16:57 moore Exp $ */
        !             2: 
        !             3: #include "ctl.h"
        !             4: 
        !             5: #include <sys/stat.h>
        !             6: #include <sgtty.h>
        !             7: #include <sys/ioctl.h>
        !             8: #include <sys/time.h>
        !             9: #include <stdio.h>
        !            10: #include <sys/wait.h>
        !            11: #include <errno.h>
        !            12: 
        !            13: char *sprintf();
        !            14: 
        !            15: extern int errno;
        !            16: extern char hostname[];
        !            17: int nofork = 0;                /* to be set from the debugger */
        !            18: 
        !            19: /*
        !            20:  * Because the tty driver insists on attaching a terminal-less
        !            21:  * process to any terminal that it writes on, we must fork a child
        !            22:  * to protect ourselves
        !            23:  */
        !            24: 
        !            25: announce(request, remote_machine)
        !            26: CTL_MSG *request;
        !            27: char *remote_machine;
        !            28: {
        !            29:     int pid, val, status;
        !            30: 
        !            31:     if (nofork) {
        !            32:        return(announce_proc(request, remote_machine));
        !            33:     }
        !            34: 
        !            35:     if ( pid = fork() ) {
        !            36: 
        !            37:            /* we are the parent, so wait for the child */
        !            38: 
        !            39:        if (pid == -1) {
        !            40:                /* the fork failed */
        !            41:            return(FAILED);
        !            42:        }
        !            43: 
        !            44:        do {
        !            45:            val = wait(&status);
        !            46:            if (val == -1) {
        !            47:                if (errno == EINTR) {
        !            48:                    continue;
        !            49:                } else {
        !            50:                        /* shouldn't happen */
        !            51:                    print_error("wait");
        !            52:                    return(FAILED);
        !            53:                }
        !            54:            }
        !            55:        } while (val != pid);
        !            56: 
        !            57:        if (status&0377 > 0) {
        !            58:                /* we were killed by some signal */
        !            59:            return(FAILED);
        !            60:        }
        !            61: 
        !            62:            /* Get the second byte, this is the exit/return code */
        !            63: 
        !            64:        return((status>>8)&0377);
        !            65: 
        !            66:     } else {
        !            67:            /* we are the child, go and do it */
        !            68:        _exit(announce_proc(request, remote_machine));
        !            69:     }
        !            70: }
        !            71:        
        !            72: 
        !            73:     /* See if the user is accepting messages. If so, announce that 
        !            74:        a talk is requested.
        !            75:      */
        !            76: 
        !            77: announce_proc(request, remote_machine)
        !            78: CTL_MSG *request;
        !            79: char *remote_machine;
        !            80: {
        !            81:     int pid, status;
        !            82:     char full_tty[32];
        !            83:     FILE *tf;
        !            84:     struct stat stbuf;
        !            85: 
        !            86: 
        !            87:     (void) sprintf(full_tty, "/dev/%s", request->r_tty);
        !            88: 
        !            89:     if (access(full_tty, 0) != 0) {
        !            90:        return(FAILED);
        !            91:     }
        !            92: 
        !            93:     if ((tf = fopen(full_tty, "w")) == NULL) {
        !            94:        return(PERMISSION_DENIED);
        !            95:     }
        !            96: 
        !            97:        /* open gratuitously attaches the talkd to
        !            98:           any tty it opens, so disconnect us from the
        !            99:           tty before we catch a signal */
        !           100: 
        !           101:     ioctl(fileno(tf), TIOCNOTTY, (struct sgttyb *) 0);
        !           102: 
        !           103:     if (fstat(fileno(tf), &stbuf) < 0) {
        !           104:        return(PERMISSION_DENIED);
        !           105:     }
        !           106: 
        !           107:     if ((stbuf.st_mode&02) == 0) {
        !           108:        return(PERMISSION_DENIED);
        !           109:     }
        !           110: 
        !           111:     print_mesg(tf, request, remote_machine);
        !           112:     fclose(tf);
        !           113:     return(SUCCESS);
        !           114: }
        !           115: 
        !           116: #define max(a,b) ( (a) > (b) ? (a) : (b) )
        !           117: #define N_LINES 5
        !           118: #define N_CHARS 120
        !           119: 
        !           120:     /*
        !           121:      * build a block of characters containing the message. 
        !           122:      * It is sent blank filled and in a single block to
        !           123:      * try to keep the message in one piece if the recipient
        !           124:      * in in vi at the time
        !           125:      */
        !           126: 
        !           127: print_mesg(tf, request, remote_machine)
        !           128: FILE *tf;
        !           129: CTL_MSG *request;
        !           130: char *remote_machine;
        !           131: {
        !           132:     struct timeval clock;
        !           133:     struct timezone zone;
        !           134:     struct tm *localtime();
        !           135:     struct tm *localclock;
        !           136:     char line_buf[N_LINES][N_CHARS];
        !           137:     int sizes[N_LINES];
        !           138:     char big_buf[N_LINES*N_CHARS];
        !           139:     char *bptr, *lptr;
        !           140:     int i, j, max_size;
        !           141: 
        !           142:     i = 0;
        !           143:     max_size = 0;
        !           144: 
        !           145:     gettimeofday(&clock, &zone);
        !           146:     localclock = localtime( &clock.tv_sec );
        !           147: 
        !           148:     sprintf(line_buf[i], " ");
        !           149: 
        !           150:     sizes[i] = strlen(line_buf[i]);
        !           151:     max_size = max(max_size, sizes[i]);
        !           152:     i++;
        !           153: 
        !           154:     sprintf(line_buf[i], "Message from Talk_Daemon@%s at %d:%02d ...",
        !           155:        hostname, localclock->tm_hour , localclock->tm_min );
        !           156: 
        !           157:     sizes[i] = strlen(line_buf[i]);
        !           158:     max_size = max(max_size, sizes[i]);
        !           159:     i++;
        !           160: 
        !           161:     sprintf(line_buf[i], "talk: connection requested by %s@%s.",
        !           162:                request->l_name, remote_machine);
        !           163: 
        !           164:     sizes[i] = strlen(line_buf[i]);
        !           165:     max_size = max(max_size, sizes[i]);
        !           166:     i++;
        !           167: 
        !           168:     sprintf(line_buf[i], "talk: respond with:  talk %s@%s",
        !           169:                request->l_name, remote_machine);
        !           170: 
        !           171:     sizes[i] = strlen(line_buf[i]);
        !           172:     max_size = max(max_size, sizes[i]);
        !           173:     i++;
        !           174: 
        !           175:     sprintf(line_buf[i], " ");
        !           176: 
        !           177:     sizes[i] = strlen(line_buf[i]);
        !           178:     max_size = max(max_size, sizes[i]);
        !           179:     i++;
        !           180: 
        !           181:     bptr = big_buf;
        !           182:     *(bptr++) = '';   /* send something to wake them up */
        !           183:     *(bptr++) = '\r';  /* add a \r in case of raw mode */
        !           184:     *(bptr++) = '\n';
        !           185:     for(i = 0; i < N_LINES; i++) {
        !           186: 
        !           187:            /* copy the line into the big buffer */
        !           188: 
        !           189:        lptr = line_buf[i];
        !           190:        while (*lptr != '\0') {
        !           191:            *(bptr++) = *(lptr++);
        !           192:        }
        !           193: 
        !           194:            /* pad out the rest of the lines with blanks */
        !           195: 
        !           196:        for(j = sizes[i]; j < max_size + 2; j++) {
        !           197:            *(bptr++) = ' ';
        !           198:        }
        !           199: 
        !           200:        *(bptr++) = '\r';       /* add a \r in case of raw mode */
        !           201:        *(bptr++) = '\n';
        !           202:     }
        !           203:     *bptr = '\0';
        !           204: 
        !           205:     fprintf(tf, big_buf);
        !           206:     fflush(tf);
        !           207:     ioctl(fileno(tf), TIOCNOTTY, (struct sgttyb *) 0);
        !           208: }

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