/usr.bin/rlogin/rlogin.c
https://bitbucket.org/freebsd/freebsd-head/ · C · 722 lines · 531 code · 74 blank · 117 comment · 127 complexity · ae2018e654fcd64743098dc9ab03eaee MD5 · raw file
- /*
- * Copyright (c) 1983, 1990, 1993
- * The Regents of the University of California. All rights reserved.
- * Copyright (c) 2002 Networks Associates Technology, Inc.
- * All rights reserved.
- *
- * Portions of this software were developed for the FreeBSD Project by
- * ThinkSec AS and NAI Labs, the Security Research Division of Network
- * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
- * ("CBOSS"), as part of the DARPA CHATS research program.
- *
- * 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. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. 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.
- */
- #ifndef lint
- static const char copyright[] =
- "@(#) Copyright (c) 1983, 1990, 1993\n\
- The Regents of the University of California. All rights reserved.\n";
- #endif /* not lint */
- #if 0
- #ifndef lint
- static const char sccsid[] = "@(#)rlogin.c 8.1 (Berkeley) 6/6/93";
- #endif /* not lint */
- #endif
- #include <sys/cdefs.h>
- __FBSDID("$FreeBSD$");
- /*
- * rlogin - remote login
- */
- #include <sys/param.h>
- #include <sys/ioctl.h>
- #include <sys/socket.h>
- #include <sys/time.h>
- #include <sys/resource.h>
- #include <sys/wait.h>
- #include <netinet/in.h>
- #include <netinet/in_systm.h>
- #include <netinet/ip.h>
- #include <netinet/tcp.h>
- #include <err.h>
- #include <errno.h>
- #include <fcntl.h>
- #include <netdb.h>
- #include <paths.h>
- #include <pwd.h>
- #include <setjmp.h>
- #include <termios.h>
- #include <signal.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <unistd.h>
- #ifndef TIOCPKT_WINDOW
- #define TIOCPKT_WINDOW 0x80
- #endif
- /* concession to Sun */
- #ifndef SIGUSR1
- #define SIGUSR1 30
- #endif
- int eight, rem;
- struct termios deftty;
- int family = PF_UNSPEC;
- int noescape;
- u_char escapechar = '~';
- #define get_window_size(fd, wp) ioctl(fd, TIOCGWINSZ, wp)
- struct winsize winsize;
- void catch_child(int);
- void copytochild(int);
- void doit(long) __dead2;
- void done(int) __dead2;
- void echo(char);
- u_int getescape(const char *);
- void lostpeer(int);
- void mode(int);
- void msg(const char *);
- void oob(int);
- int reader(int);
- void sendwindow(void);
- void setsignal(int);
- void sigwinch(int);
- void stop(char);
- void usage(void) __dead2;
- void writer(void);
- void writeroob(int);
- int
- main(int argc, char *argv[])
- {
- struct passwd *pw;
- struct servent *sp;
- struct termios tty;
- long omask;
- int argoff, ch, dflag, Dflag, one;
- uid_t uid;
- char *host, *localname, *p, *user, term[1024];
- speed_t ospeed;
- struct sockaddr_storage ss;
- socklen_t sslen;
- size_t len, len2;
- int i;
- argoff = dflag = Dflag = 0;
- one = 1;
- host = localname = user = NULL;
- if ((p = strrchr(argv[0], '/')))
- ++p;
- else
- p = argv[0];
- if (strcmp(p, "rlogin"))
- host = p;
- /* handle "rlogin host flags" */
- if (!host && argc > 2 && argv[1][0] != '-') {
- host = argv[1];
- argoff = 1;
- }
- #define OPTIONS "468DEde:i:l:"
- while ((ch = getopt(argc - argoff, argv + argoff, OPTIONS)) != -1)
- switch(ch) {
- case '4':
- family = PF_INET;
- break;
- case '6':
- family = PF_INET6;
- break;
- case '8':
- eight = 1;
- break;
- case 'D':
- Dflag = 1;
- break;
- case 'E':
- noescape = 1;
- break;
- case 'd':
- dflag = 1;
- break;
- case 'e':
- noescape = 0;
- escapechar = getescape(optarg);
- break;
- case 'i':
- if (getuid() != 0)
- errx(1, "-i user: permission denied");
- localname = optarg;
- break;
- case 'l':
- user = optarg;
- break;
- case '?':
- default:
- usage();
- }
- optind += argoff;
- /* if haven't gotten a host yet, do so */
- if (!host && !(host = argv[optind++]))
- usage();
- if (argv[optind])
- usage();
- if (!(pw = getpwuid(uid = getuid())))
- errx(1, "unknown user id");
- if (!user)
- user = pw->pw_name;
- if (!localname)
- localname = pw->pw_name;
- sp = NULL;
- sp = getservbyname("login", "tcp");
- if (sp == NULL)
- errx(1, "login/tcp: unknown service");
- if ((p = getenv("TERM")) != NULL)
- (void)strlcpy(term, p, sizeof(term));
- len = strlen(term);
- if (len < (sizeof(term) - 1) && tcgetattr(0, &tty) == 0) {
- /* start at 2 to include the / */
- for (ospeed = i = cfgetospeed(&tty), len2 = 2; i > 9; len2++)
- i /= 10;
- if (len + len2 < sizeof(term))
- (void)snprintf(term + len, len2 + 1, "/%d", ospeed);
- }
- (void)get_window_size(0, &winsize);
- (void)signal(SIGPIPE, lostpeer);
- /* will use SIGUSR1 for window size hack, so hold it off */
- omask = sigblock(sigmask(SIGURG) | sigmask(SIGUSR1));
- /*
- * We set SIGURG and SIGUSR1 below so that an
- * incoming signal will be held pending rather than being
- * discarded. Note that these routines will be ready to get
- * a signal by the time that they are unblocked below.
- */
- (void)signal(SIGURG, copytochild);
- (void)signal(SIGUSR1, writeroob);
- rem = rcmd_af(&host, sp->s_port, localname, user, term, 0, family);
- if (rem < 0)
- exit(1);
- if (dflag &&
- setsockopt(rem, SOL_SOCKET, SO_DEBUG, &one, sizeof(one)) < 0)
- warn("setsockopt");
- if (Dflag &&
- setsockopt(rem, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)) < 0)
- warn("setsockopt NODELAY (ignored)");
- sslen = sizeof(ss);
- one = IPTOS_LOWDELAY;
- if (getsockname(rem, (struct sockaddr *)&ss, &sslen) == 0 &&
- ss.ss_family == AF_INET) {
- if (setsockopt(rem, IPPROTO_IP, IP_TOS, (char *)&one,
- sizeof(int)) < 0)
- warn("setsockopt TOS (ignored)");
- } else
- if (ss.ss_family == AF_INET)
- warn("setsockopt getsockname failed");
- (void)setuid(uid);
- doit(omask);
- /*NOTREACHED*/
- }
- int child;
- void
- doit(long omask)
- {
- (void)signal(SIGINT, SIG_IGN);
- setsignal(SIGHUP);
- setsignal(SIGQUIT);
- mode(1);
- child = fork();
- if (child == -1) {
- warn("fork");
- done(1);
- }
- if (child == 0) {
- if (reader(omask) == 0) {
- msg("connection closed");
- exit(0);
- }
- sleep(1);
- msg("\007connection closed");
- exit(1);
- }
- /*
- * We may still own the socket, and may have a pending SIGURG (or might
- * receive one soon) that we really want to send to the reader. When
- * one of these comes in, the trap copytochild simply copies such
- * signals to the child. We can now unblock SIGURG and SIGUSR1
- * that were set above.
- */
- (void)sigsetmask(omask);
- (void)signal(SIGCHLD, catch_child);
- writer();
- msg("closed connection");
- done(0);
- }
- /* trap a signal, unless it is being ignored. */
- void
- setsignal(int sig)
- {
- int omask = sigblock(sigmask(sig));
- if (signal(sig, exit) == SIG_IGN)
- (void)signal(sig, SIG_IGN);
- (void)sigsetmask(omask);
- }
- void
- done(int status)
- {
- int w, wstatus;
- mode(0);
- if (child > 0) {
- /* make sure catch_child does not snap it up */
- (void)signal(SIGCHLD, SIG_DFL);
- if (kill(child, SIGKILL) >= 0)
- while ((w = wait(&wstatus)) > 0 && w != child);
- }
- exit(status);
- }
- int dosigwinch;
- /*
- * This is called when the reader process gets the out-of-band (urgent)
- * request to turn on the window-changing protocol.
- */
- /* ARGSUSED */
- void
- writeroob(int signo __unused)
- {
- if (dosigwinch == 0) {
- sendwindow();
- (void)signal(SIGWINCH, sigwinch);
- }
- dosigwinch = 1;
- }
- /* ARGSUSED */
- void
- catch_child(int signo __unused)
- {
- pid_t pid;
- int status;
- for (;;) {
- pid = wait3(&status, WNOHANG|WUNTRACED, NULL);
- if (pid == 0)
- return;
- /* if the child (reader) dies, just quit */
- if (pid < 0 || (pid == child && !WIFSTOPPED(status)))
- done(WTERMSIG(status) | WEXITSTATUS(status));
- }
- /* NOTREACHED */
- }
- /*
- * writer: write to remote: 0 -> line.
- * ~. terminate
- * ~^Z suspend rlogin process.
- * ~<delayed-suspend char> suspend rlogin process, but leave reader alone.
- */
- void
- writer(void)
- {
- int bol, local, n;
- char c;
- bol = 1; /* beginning of line */
- local = 0;
- for (;;) {
- n = read(STDIN_FILENO, &c, 1);
- if (n <= 0) {
- if (n < 0 && errno == EINTR)
- continue;
- break;
- }
- /*
- * If we're at the beginning of the line and recognize a
- * command character, then we echo locally. Otherwise,
- * characters are echo'd remotely. If the command character
- * is doubled, this acts as a force and local echo is
- * suppressed.
- */
- if (bol) {
- bol = 0;
- if (!noescape && c == escapechar) {
- local = 1;
- continue;
- }
- } else if (local) {
- local = 0;
- if (c == '.' || CCEQ(deftty.c_cc[VEOF], c)) {
- echo(c);
- break;
- }
- if (CCEQ(deftty.c_cc[VSUSP], c) ||
- CCEQ(deftty.c_cc[VDSUSP], c)) {
- bol = 1;
- echo(c);
- stop(c);
- continue;
- }
- if (c != escapechar)
- (void)write(rem, &escapechar, 1);
- }
- if (write(rem, &c, 1) == 0) {
- msg("line gone");
- break;
- }
- bol = CCEQ(deftty.c_cc[VKILL], c) ||
- CCEQ(deftty.c_cc[VEOF], c) ||
- CCEQ(deftty.c_cc[VINTR], c) ||
- CCEQ(deftty.c_cc[VSUSP], c) ||
- c == '\r' || c == '\n';
- }
- }
- void
- echo(char c)
- {
- char *p;
- char buf[8];
- p = buf;
- c &= 0177;
- *p++ = escapechar;
- if (c < ' ') {
- *p++ = '^';
- *p++ = c + '@';
- } else if (c == 0177) {
- *p++ = '^';
- *p++ = '?';
- } else
- *p++ = c;
- *p++ = '\r';
- *p++ = '\n';
- (void)write(STDOUT_FILENO, buf, p - buf);
- }
- void
- stop(char cmdc)
- {
- mode(0);
- (void)signal(SIGCHLD, SIG_IGN);
- (void)kill(CCEQ(deftty.c_cc[VSUSP], cmdc) ? 0 : getpid(), SIGTSTP);
- (void)signal(SIGCHLD, catch_child);
- mode(1);
- sigwinch(0); /* check for size changes */
- }
- /* ARGSUSED */
- void
- sigwinch(int signo __unused)
- {
- struct winsize ws;
- if (dosigwinch && get_window_size(0, &ws) == 0 &&
- bcmp(&ws, &winsize, sizeof(ws))) {
- winsize = ws;
- sendwindow();
- }
- }
- /*
- * Send the window size to the server via the magic escape
- */
- void
- sendwindow(void)
- {
- struct winsize ws;
- char obuf[4 + sizeof (struct winsize)];
- obuf[0] = 0377;
- obuf[1] = 0377;
- obuf[2] = 's';
- obuf[3] = 's';
- ws.ws_row = htons(winsize.ws_row);
- ws.ws_col = htons(winsize.ws_col);
- ws.ws_xpixel = htons(winsize.ws_xpixel);
- ws.ws_ypixel = htons(winsize.ws_ypixel);
- bcopy(&ws, obuf + 4, sizeof(ws));
- (void)write(rem, obuf, sizeof(obuf));
- }
- /*
- * reader: read from remote: line -> 1
- */
- #define READING 1
- #define WRITING 2
- jmp_buf rcvtop;
- int rcvcnt, rcvstate;
- pid_t ppid;
- char rcvbuf[8 * 1024];
- /* ARGSUSED */
- void
- oob(int signo __unused)
- {
- struct termios tty;
- int atmark, n, rcvd;
- char waste[BUFSIZ], mark;
- rcvd = 0;
- while (recv(rem, &mark, 1, MSG_OOB) < 0) {
- switch (errno) {
- case EWOULDBLOCK:
- /*
- * Urgent data not here yet. It may not be possible
- * to send it yet if we are blocked for output and
- * our input buffer is full.
- */
- if (rcvcnt < (int)sizeof(rcvbuf)) {
- n = read(rem, rcvbuf + rcvcnt,
- sizeof(rcvbuf) - rcvcnt);
- if (n <= 0)
- return;
- rcvd += n;
- } else {
- n = read(rem, waste, sizeof(waste));
- if (n <= 0)
- return;
- }
- continue;
- default:
- return;
- }
- }
- if (mark & TIOCPKT_WINDOW) {
- /* Let server know about window size changes */
- (void)kill(ppid, SIGUSR1);
- }
- if (!eight && (mark & TIOCPKT_NOSTOP)) {
- (void)tcgetattr(0, &tty);
- tty.c_iflag &= ~IXON;
- (void)tcsetattr(0, TCSANOW, &tty);
- }
- if (!eight && (mark & TIOCPKT_DOSTOP)) {
- (void)tcgetattr(0, &tty);
- tty.c_iflag |= (deftty.c_iflag & IXON);
- (void)tcsetattr(0, TCSANOW, &tty);
- }
- if (mark & TIOCPKT_FLUSHWRITE) {
- (void)tcflush(1, TCIOFLUSH);
- for (;;) {
- if (ioctl(rem, SIOCATMARK, &atmark) < 0) {
- warn("ioctl");
- break;
- }
- if (atmark)
- break;
- n = read(rem, waste, sizeof (waste));
- if (n <= 0)
- break;
- }
- /*
- * Don't want any pending data to be output, so clear the recv
- * buffer. If we were hanging on a write when interrupted,
- * don't want it to restart. If we were reading, restart
- * anyway.
- */
- rcvcnt = 0;
- longjmp(rcvtop, 1);
- }
- /* oob does not do FLUSHREAD (alas!) */
- /*
- * If we filled the receive buffer while a read was pending, longjmp
- * to the top to restart appropriately. Don't abort a pending write,
- * however, or we won't know how much was written.
- */
- if (rcvd && rcvstate == READING)
- longjmp(rcvtop, 1);
- }
- /* reader: read from remote: line -> 1 */
- int
- reader(int omask)
- {
- int n, remaining;
- char *bufp;
- pid_t pid;
- pid = getpid();
- (void)signal(SIGTTOU, SIG_IGN);
- (void)signal(SIGURG, oob);
- (void)signal(SIGUSR1, oob); /* When propogating SIGURG from parent */
- ppid = getppid();
- (void)fcntl(rem, F_SETOWN, pid);
- (void)setjmp(rcvtop);
- (void)sigsetmask(omask);
- bufp = rcvbuf;
- for (;;) {
- while ((remaining = rcvcnt - (bufp - rcvbuf)) > 0) {
- rcvstate = WRITING;
- n = write(STDOUT_FILENO, bufp, remaining);
- if (n < 0) {
- if (errno != EINTR)
- return (-1);
- continue;
- }
- bufp += n;
- }
- bufp = rcvbuf;
- rcvcnt = 0;
- rcvstate = READING;
- rcvcnt = read(rem, rcvbuf, sizeof (rcvbuf));
- if (rcvcnt == 0)
- return (0);
- if (rcvcnt < 0) {
- if (errno == EINTR)
- continue;
- warn("read");
- return (-1);
- }
- }
- }
- void
- mode(int f)
- {
- struct termios tty;
- switch (f) {
- case 0:
- (void)tcsetattr(0, TCSANOW, &deftty);
- break;
- case 1:
- (void)tcgetattr(0, &deftty);
- tty = deftty;
- /* This is loosely derived from sys/kern/tty_compat.c. */
- tty.c_lflag &= ~(ECHO|ICANON|ISIG|IEXTEN);
- tty.c_iflag &= ~ICRNL;
- tty.c_oflag &= ~OPOST;
- tty.c_cc[VMIN] = 1;
- tty.c_cc[VTIME] = 0;
- if (eight) {
- tty.c_iflag &= IXOFF;
- tty.c_cflag &= ~(CSIZE|PARENB);
- tty.c_cflag |= CS8;
- }
- (void)tcsetattr(0, TCSANOW, &tty);
- break;
- default:
- return;
- }
- }
- /* ARGSUSED */
- void
- lostpeer(int signo __unused)
- {
- (void)signal(SIGPIPE, SIG_IGN);
- msg("\007connection closed");
- done(1);
- }
- /* copy SIGURGs to the child process via SIGUSR1. */
- /* ARGSUSED */
- void
- copytochild(int signo __unused)
- {
- (void)kill(child, SIGUSR1);
- }
- void
- msg(const char *str)
- {
- (void)fprintf(stderr, "rlogin: %s\r\n", str);
- }
- void
- usage(void)
- {
- (void)fprintf(stderr,
- "usage: rlogin [-46%s]%s[-e char] [-i localname] [-l username] host\n",
- "8DEd", " ");
- exit(1);
- }
- u_int
- getescape(const char *p)
- {
- long val;
- size_t len;
- if ((len = strlen(p)) == 1) /* use any single char, including '\' */
- return ((u_int)*p);
- /* otherwise, \nnn */
- if (*p == '\\' && len >= 2 && len <= 4) {
- val = strtol(++p, NULL, 8);
- for (;;) {
- if (!*++p)
- return ((u_int)val);
- if (*p < '0' || *p > '8')
- break;
- }
- }
- msg("illegal option value -- e");
- usage();
- /* NOTREACHED */
- }