11590Srgrimes/* 21590Srgrimes * Copyright (c) 1989, 1993 31590Srgrimes * The Regents of the University of California. All rights reserved. 41590Srgrimes * 51590Srgrimes * This code is derived from software contributed to Berkeley by 61590Srgrimes * Jef Poskanzer and Craig Leres of the Lawrence Berkeley Laboratory. 71590Srgrimes * 81590Srgrimes * Redistribution and use in source and binary forms, with or without 91590Srgrimes * modification, are permitted provided that the following conditions 101590Srgrimes * are met: 111590Srgrimes * 1. Redistributions of source code must retain the above copyright 121590Srgrimes * notice, this list of conditions and the following disclaimer. 131590Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 141590Srgrimes * notice, this list of conditions and the following disclaimer in the 151590Srgrimes * documentation and/or other materials provided with the distribution. 161590Srgrimes * 4. Neither the name of the University nor the names of its contributors 171590Srgrimes * may be used to endorse or promote products derived from this software 181590Srgrimes * without specific prior written permission. 191590Srgrimes * 201590Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 211590Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 221590Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 231590Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 241590Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 251590Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 261590Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 271590Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 281590Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 291590Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 301590Srgrimes * SUCH DAMAGE. 311590Srgrimes */ 321590Srgrimes 331590Srgrimes#ifndef lint 3428794Scharnierstatic const char copyright[] = 351590Srgrimes"@(#) Copyright (c) 1989, 1993\n\ 361590Srgrimes The Regents of the University of California. All rights reserved.\n"; 3787682Smarkm#endif 381590Srgrimes 3991378Sdwmalone#if 0 401590Srgrimes#ifndef lint 4191378Sdwmalonestatic char sccsid[] = "@(#)write.c 8.1 (Berkeley) 6/6/93"; 4228794Scharnier#endif 4391378Sdwmalone#endif 441590Srgrimes 4591378Sdwmalone#include <sys/cdefs.h> 4691378Sdwmalone__FBSDID("$FreeBSD: releng/11.0/usr.bin/write/write.c 231586 2012-02-13 14:40:15Z glebius $"); 4791378Sdwmalone 481590Srgrimes#include <sys/param.h> 491590Srgrimes#include <sys/signal.h> 501590Srgrimes#include <sys/stat.h> 511590Srgrimes#include <sys/file.h> 521590Srgrimes#include <sys/time.h> 531590Srgrimes#include <ctype.h> 5428794Scharnier#include <err.h> 5529430Sache#include <locale.h> 5619190Salex#include <paths.h> 571590Srgrimes#include <pwd.h> 581590Srgrimes#include <stdio.h> 5991378Sdwmalone#include <stdlib.h> 601590Srgrimes#include <string.h> 6128794Scharnier#include <unistd.h> 62202200Sed#include <utmpx.h> 63231586Sglebius#include <wchar.h> 64231586Sglebius#include <wctype.h> 651590Srgrimes 6692922Simpvoid done(int); 6792922Simpvoid do_write(char *, char *, uid_t); 6892922Simpstatic void usage(void); 6992922Simpint term_chk(char *, int *, time_t *, int); 70231586Sglebiusvoid wr_fputs(wchar_t *s); 7192922Simpvoid search_utmp(char *, char *, char *, uid_t); 7292922Simpint utmp_chk(char *, char *); 731590Srgrimes 7428794Scharnierint 75102944Sdwmalonemain(int argc, char **argv) 761590Srgrimes{ 771590Srgrimes time_t atime; 781590Srgrimes uid_t myuid; 791590Srgrimes int msgsok, myttyfd; 8028794Scharnier char tty[MAXPATHLEN], *mytty; 811590Srgrimes 8229430Sache (void)setlocale(LC_CTYPE, ""); 8329430Sache 8497454Stjr while (getopt(argc, argv, "") != -1) 8597454Stjr usage(); 8697454Stjr argc -= optind; 8797454Stjr argv += optind; 8897454Stjr 891590Srgrimes /* check that sender has write enabled */ 901590Srgrimes if (isatty(fileno(stdin))) 911590Srgrimes myttyfd = fileno(stdin); 921590Srgrimes else if (isatty(fileno(stdout))) 931590Srgrimes myttyfd = fileno(stdout); 941590Srgrimes else if (isatty(fileno(stderr))) 951590Srgrimes myttyfd = fileno(stderr); 9628794Scharnier else 9728794Scharnier errx(1, "can't find your tty"); 9828794Scharnier if (!(mytty = ttyname(myttyfd))) 9928794Scharnier errx(1, "can't find your tty's name"); 100173572Sjhb if (!strncmp(mytty, _PATH_DEV, strlen(_PATH_DEV))) 101173572Sjhb mytty += strlen(_PATH_DEV); 1021590Srgrimes if (term_chk(mytty, &msgsok, &atime, 1)) 1031590Srgrimes exit(1); 10428794Scharnier if (!msgsok) 10528794Scharnier errx(1, "you have write permission turned off"); 1061590Srgrimes 1071590Srgrimes myuid = getuid(); 1081590Srgrimes 1091590Srgrimes /* check args */ 1101590Srgrimes switch (argc) { 11197454Stjr case 1: 11297454Stjr search_utmp(argv[0], tty, mytty, myuid); 1131590Srgrimes do_write(tty, mytty, myuid); 1141590Srgrimes break; 11597454Stjr case 2: 11697454Stjr if (!strncmp(argv[1], _PATH_DEV, strlen(_PATH_DEV))) 11797454Stjr argv[1] += strlen(_PATH_DEV); 11897454Stjr if (utmp_chk(argv[0], argv[1])) 11997454Stjr errx(1, "%s is not logged in on %s", argv[0], argv[1]); 12097454Stjr if (term_chk(argv[1], &msgsok, &atime, 1)) 1211590Srgrimes exit(1); 12228794Scharnier if (myuid && !msgsok) 12397454Stjr errx(1, "%s has messages disabled on %s", argv[0], argv[1]); 12497454Stjr do_write(argv[1], mytty, myuid); 1251590Srgrimes break; 1261590Srgrimes default: 12728794Scharnier usage(); 1281590Srgrimes } 12929430Sache done(0); 13028794Scharnier return (0); 1311590Srgrimes} 1321590Srgrimes 13328794Scharnierstatic void 134102944Sdwmaloneusage(void) 13528794Scharnier{ 13628794Scharnier (void)fprintf(stderr, "usage: write user [tty]\n"); 13728794Scharnier exit(1); 13828794Scharnier} 13928794Scharnier 1401590Srgrimes/* 1411590Srgrimes * utmp_chk - checks that the given user is actually logged in on 1421590Srgrimes * the given tty 1431590Srgrimes */ 14428794Scharnierint 145102944Sdwmaloneutmp_chk(char *user, char *tty) 1461590Srgrimes{ 147200160Sed struct utmpx lu, *u; 1481590Srgrimes 149200160Sed strncpy(lu.ut_line, tty, sizeof lu.ut_line); 150200160Sed setutxent(); 151200160Sed while ((u = getutxline(&lu)) != NULL) 152200160Sed if (u->ut_type == USER_PROCESS && 153200160Sed strcmp(user, u->ut_user) == 0) { 154200160Sed endutxent(); 1551590Srgrimes return(0); 1561590Srgrimes } 157200160Sed endutxent(); 1581590Srgrimes return(1); 1591590Srgrimes} 1601590Srgrimes 1611590Srgrimes/* 1621590Srgrimes * search_utmp - search utmp for the "best" terminal to write to 1631590Srgrimes * 1641590Srgrimes * Ignores terminals with messages disabled, and of the rest, returns 1651590Srgrimes * the one with the most recent access time. Returns as value the number 1661590Srgrimes * of the user's terminals with messages enabled, or -1 if the user is 1671590Srgrimes * not logged in at all. 1681590Srgrimes * 1691590Srgrimes * Special case for writing to yourself - ignore the terminal you're 1701590Srgrimes * writing from, unless that's the only terminal with messages enabled. 1711590Srgrimes */ 17228794Scharniervoid 173102944Sdwmalonesearch_utmp(char *user, char *tty, char *mytty, uid_t myuid) 1741590Srgrimes{ 175200160Sed struct utmpx *u; 1761590Srgrimes time_t bestatime, atime; 177200160Sed int nloggedttys, nttys, msgsok, user_is_me; 1781590Srgrimes 1791590Srgrimes nloggedttys = nttys = 0; 1801590Srgrimes bestatime = 0; 1811590Srgrimes user_is_me = 0; 182200160Sed 183200160Sed setutxent(); 184200160Sed while ((u = getutxent()) != NULL) 185200160Sed if (u->ut_type == USER_PROCESS && 186200160Sed strcmp(user, u->ut_user) == 0) { 1871590Srgrimes ++nloggedttys; 188200160Sed if (term_chk(u->ut_line, &msgsok, &atime, 0)) 1891590Srgrimes continue; /* bad term? skip */ 1901590Srgrimes if (myuid && !msgsok) 1911590Srgrimes continue; /* skip ttys with msgs off */ 192200160Sed if (strcmp(u->ut_line, mytty) == 0) { 1931590Srgrimes user_is_me = 1; 1941590Srgrimes continue; /* don't write to yourself */ 1951590Srgrimes } 1961590Srgrimes ++nttys; 1971590Srgrimes if (atime > bestatime) { 1981590Srgrimes bestatime = atime; 199200160Sed (void)strlcpy(tty, u->ut_line, MAXPATHLEN); 2001590Srgrimes } 2011590Srgrimes } 202200160Sed endutxent(); 2031590Srgrimes 20428794Scharnier if (nloggedttys == 0) 20528794Scharnier errx(1, "%s is not logged in", user); 2061590Srgrimes if (nttys == 0) { 2071590Srgrimes if (user_is_me) { /* ok, so write to yourself! */ 208200160Sed (void)strlcpy(tty, mytty, MAXPATHLEN); 2091590Srgrimes return; 2101590Srgrimes } 21128794Scharnier errx(1, "%s has messages disabled", user); 2121590Srgrimes } else if (nttys > 1) { 21328794Scharnier warnx("%s is logged in more than once; writing to %s", user, tty); 2141590Srgrimes } 2151590Srgrimes} 2161590Srgrimes 2171590Srgrimes/* 2181590Srgrimes * term_chk - check that a terminal exists, and get the message bit 2191590Srgrimes * and the access time 2201590Srgrimes */ 22128794Scharnierint 222102944Sdwmaloneterm_chk(char *tty, int *msgsokP, time_t *atimeP, int showerror) 2231590Srgrimes{ 2241590Srgrimes struct stat s; 2251590Srgrimes char path[MAXPATHLEN]; 2261590Srgrimes 22719190Salex (void)snprintf(path, sizeof(path), "%s%s", _PATH_DEV, tty); 2281590Srgrimes if (stat(path, &s) < 0) { 2291590Srgrimes if (showerror) 23028794Scharnier warn("%s", path); 2311590Srgrimes return(1); 2321590Srgrimes } 2331590Srgrimes *msgsokP = (s.st_mode & (S_IWRITE >> 3)) != 0; /* group write bit */ 2341590Srgrimes *atimeP = s.st_atime; 2351590Srgrimes return(0); 2361590Srgrimes} 2371590Srgrimes 2381590Srgrimes/* 2391590Srgrimes * do_write - actually make the connection 2401590Srgrimes */ 24128794Scharniervoid 242102944Sdwmalonedo_write(char *tty, char *mytty, uid_t myuid) 2431590Srgrimes{ 24487682Smarkm const char *login; 24587682Smarkm char *nows; 24687682Smarkm struct passwd *pwd; 24728794Scharnier time_t now; 248231586Sglebius char path[MAXPATHLEN], host[MAXHOSTNAMELEN]; 249231586Sglebius wchar_t line[512]; 2501590Srgrimes 251139718Scognet /* Determine our login name before we reopen() stdout */ 25248566Sbillf if ((login = getlogin()) == NULL) { 25328794Scharnier if ((pwd = getpwuid(myuid))) 2541590Srgrimes login = pwd->pw_name; 2551590Srgrimes else 2561590Srgrimes login = "???"; 25748566Sbillf } 2581590Srgrimes 25919190Salex (void)snprintf(path, sizeof(path), "%s%s", _PATH_DEV, tty); 26028794Scharnier if ((freopen(path, "w", stdout)) == NULL) 26128794Scharnier err(1, "%s", path); 2621590Srgrimes 2631590Srgrimes (void)signal(SIGINT, done); 2641590Srgrimes (void)signal(SIGHUP, done); 2651590Srgrimes 2661590Srgrimes /* print greeting */ 2671590Srgrimes if (gethostname(host, sizeof(host)) < 0) 2681590Srgrimes (void)strcpy(host, "???"); 2691590Srgrimes now = time((time_t *)NULL); 2701590Srgrimes nows = ctime(&now); 2711590Srgrimes nows[16] = '\0'; 2721590Srgrimes (void)printf("\r\n\007\007\007Message from %s@%s on %s at %s ...\r\n", 2731590Srgrimes login, host, mytty, nows + 11); 2741590Srgrimes 275231586Sglebius while (fgetws(line, sizeof(line)/sizeof(wchar_t), stdin) != NULL) 2761590Srgrimes wr_fputs(line); 2771590Srgrimes} 2781590Srgrimes 2791590Srgrimes/* 2801590Srgrimes * done - cleanup and exit 2811590Srgrimes */ 2821590Srgrimesvoid 283102944Sdwmalonedone(int n __unused) 2841590Srgrimes{ 2851590Srgrimes (void)printf("EOF\r\n"); 2861590Srgrimes exit(0); 2871590Srgrimes} 2881590Srgrimes 2891590Srgrimes/* 2901590Srgrimes * wr_fputs - like fputs(), but makes control characters visible and 2911590Srgrimes * turns \n into \r\n 2921590Srgrimes */ 29328794Scharniervoid 294231586Sglebiuswr_fputs(wchar_t *s) 2951590Srgrimes{ 2961590Srgrimes 297231586Sglebius#define PUTC(c) if (putwchar(c) == WEOF) err(1, NULL); 2981590Srgrimes 299231586Sglebius for (; *s != L'\0'; ++s) { 300231586Sglebius if (*s == L'\n') { 301231586Sglebius PUTC(L'\r'); 302231586Sglebius PUTC(L'\n'); 303231586Sglebius } else if (iswprint(*s) || iswspace(*s)) { 304231586Sglebius PUTC(*s); 305231586Sglebius } else { 306231586Sglebius wprintf(L"<0x%X>", *s); 30712097Sache } 3081590Srgrimes } 3091590Srgrimes return; 3101590Srgrimes#undef PUTC 3111590Srgrimes} 312