Edit
IABSD.fr/src/libexec/talkd/process.c
krw
- libexec/talkd/process.c
-
/* $OpenBSD: process.c,v 1.23 2016/03/16 15:41:10 krw Exp $ */ /* * Copyright (c) 1983 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. 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. */ /* * process.c handles the requests, which can be of three types: * ANNOUNCE - announce to a user that a talk is wanted * LEAVE_INVITE - insert the request into the table * LOOK_UP - look up to see if a request is waiting in * in the table for the local user * DELETE - delete invitation */ #include <sys/socket.h> #include <sys/stat.h> #include <arpa/inet.h> #include <protocols/talkd.h> #include <ctype.h> #include <limits.h> #include <netdb.h> #include <paths.h> #include <stdio.h> #include <string.h> #include <syslog.h> #include <utmp.h> #include "talkd.h" #define satosin(sa) ((struct sockaddr_in *)(sa)) void process_request(CTL_MSG *mp, CTL_RESPONSE *rp) { CTL_MSG *ptr; char *s; rp->vers = TALK_VERSION; rp->type = mp->type; rp->id_num = htonl(0); if (mp->vers != TALK_VERSION) { syslog(LOG_WARNING, "Bad protocol version %d", mp->vers); rp->answer = BADVERSION; return; } mp->id_num = ntohl(mp->id_num); if (ntohs(mp->addr.sa_family) != AF_INET) { syslog(LOG_WARNING, "Bad address, family %d", ntohs(mp->addr.sa_family)); rp->answer = BADADDR; return; } if (ntohs(mp->ctl_addr.sa_family) != AF_INET) { syslog(LOG_WARNING, "Bad control address, family %d", ntohs(mp->ctl_addr.sa_family)); rp->answer = BADCTLADDR; return; } for (s = mp->l_name; *s; s++) if (!isprint((unsigned char)*s)) { syslog(LOG_NOTICE, "Illegal user name. Aborting"); rp->answer = FAILED; return; } if (memcmp(&satosin(&rp->addr)->sin_addr, &satosin(&mp->ctl_addr)->sin_addr, sizeof(struct in_addr))) { char buf1[32], buf2[32]; strlcpy(buf1, inet_ntoa(satosin(&rp->addr)->sin_addr), sizeof(buf1)); strlcpy(buf2, inet_ntoa(satosin(&mp->ctl_addr)->sin_addr), sizeof(buf2)); syslog(LOG_WARNING, "addresses are different, %s != %s", buf1, buf2); } rp->addr.sa_family = 0; mp->pid = ntohl(mp->pid); if (debug) print_request("process_request", mp); switch (mp->type) { case ANNOUNCE: do_announce(mp, rp); break; case LEAVE_INVITE: ptr = find_request(mp); if (ptr != NULL) { rp->id_num = htonl(ptr->id_num); rp->answer = SUCCESS; } else insert_table(mp, rp); break; case LOOK_UP: ptr = find_match(mp); if (ptr != NULL) { rp->id_num = htonl(ptr->id_num); rp->addr = ptr->addr; rp->addr.sa_family = ptr->addr.sa_family; rp->answer = SUCCESS; } else rp->answer = NOT_HERE; break; case DELETE: rp->answer = delete_invite(mp->id_num); break; default: rp->answer = UNKNOWN_REQUEST; break; } if (debug) print_response("process_request", rp); } void do_announce(CTL_MSG *mp, CTL_RESPONSE *rp) { struct hostent *hp; CTL_MSG *ptr; int result; /* see if the user is logged */ result = find_user(mp->r_name, mp->r_tty, sizeof(mp->r_tty)); if (result != SUCCESS) { rp->answer = result; return; } hp = gethostbyaddr((char *)&satosin(&mp->ctl_addr)->sin_addr, sizeof(struct in_addr), AF_INET); if (hp == NULL) { rp->answer = MACHINE_UNKNOWN; return; } ptr = find_request(mp); if (ptr == (CTL_MSG *) 0) { insert_table(mp, rp); rp->answer = announce(mp, hp->h_name); return; } if (mp->id_num > ptr->id_num) { /* * This is an explicit re-announce, so update the id_num * field to avoid duplicates and re-announce the talk. */ ptr->id_num = new_id(); rp->id_num = htonl(ptr->id_num); rp->answer = announce(mp, hp->h_name); } else { /* a duplicated request, so ignore it */ rp->id_num = htonl(ptr->id_num); rp->answer = SUCCESS; } } /* * Search utmp for the local user */ int find_user(char *name, char *tty, size_t ttyl) { struct utmp ubuf, ubuf1; int status; FILE *fp; char line[UT_LINESIZE+1]; char ftty[PATH_MAX]; time_t idle, now; time(&now); idle = INT_MAX; if ((fp = fopen(_PATH_UTMP, "r")) == NULL) { fprintf(stderr, "talkd: can't read %s.\n", _PATH_UTMP); return (FAILED); } #define SCMPN(a, b) strncmp(a, b, sizeof(a)) status = NOT_HERE; (void) strlcpy(ftty, _PATH_DEV, sizeof(ftty)); while (fread((char *) &ubuf, sizeof(ubuf), 1, fp) == 1) if (SCMPN(ubuf.ut_name, name) == 0) { if (*tty == '\0') { /* no particular tty was requested */ struct stat statb; memcpy(line, ubuf.ut_line, UT_LINESIZE); line[sizeof(line)-1] = '\0'; ftty[sizeof(_PATH_DEV)-1] = '\0'; strlcat(ftty, line, sizeof(ftty)); if (stat(ftty, &statb) == 0) { if (!(statb.st_mode & S_IWGRP)) { if (status == NOT_HERE) status = PERMISSION_DENIED; } else if (now - statb.st_atime < idle) { idle = now - statb.st_atime; status = SUCCESS; ubuf1 = ubuf; } } } else if (SCMPN(ubuf.ut_line, tty) == 0) { status = SUCCESS; break; } } fclose(fp); if (*tty == '\0' && status == SUCCESS) { memcpy(line, ubuf1.ut_line, UT_LINESIZE); line[sizeof(line)-1] = '\0'; strlcpy(tty, line, ttyl); } return (status); }