Annotation of 42BSD/ucb/talk/announce.c, revision 1.1.1.1

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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