#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#include <signal.h>
#include <fcntl.h>
#include <termios.h>
+#include <grp.h>
+#include <utmp.h>
+#include <pwd.h>
+#include <time.h>
+#include <sys/types.h>
+#include <sys/wait.h>
#include <sys/ioctl.h>
#include "putty.h"
#define TRUE 1
#endif
+#ifndef UTMP_FILE
+#define UTMP_FILE "/var/run/utmp"
+#endif
+#ifndef WTMP_FILE
+#define WTMP_FILE "/var/log/wtmp"
+#endif
+#ifndef LASTLOG_FILE
+#ifdef _PATH_LASTLOG
+#define LASTLOG_FILE _PATH_LASTLOG
+#else
+#define LASTLOG_FILE "/var/log/lastlog"
+#endif
+#endif
+
+/*
+ * Set up a default for vaguely sane systems. The idea is that if
+ * OMIT_UTMP is not defined, then at least one of the symbols which
+ * enable particular forms of utmp processing should be, if only so
+ * that a link error can warn you that you should have defined
+ * OMIT_UTMP if you didn't want any. Currently HAVE_PUTUTLINE is
+ * the only such symbol.
+ */
+#ifndef OMIT_UTMP
+#if !defined HAVE_PUTUTLINE
+#define HAVE_PUTUTLINE
+#endif
+#endif
+
int pty_master_fd;
+static int pty_stamped_utmp = 0;
+static int pty_child_pid;
+static sig_atomic_t pty_child_dead;
+#ifndef OMIT_UTMP
+static struct utmp utmp_entry;
+#endif
+char **pty_argv;
+
+int pty_child_is_dead(void)
+{
+ return pty_child_dead;
+}
static void pty_size(void);
+static void setup_utmp(char *ttyname)
+{
+#ifndef OMIT_UTMP
+#ifdef HAVE_LASTLOG
+ struct lastlog lastlog_entry;
+ FILE *lastlog;
+#endif
+ struct passwd *pw;
+ char *location;
+ FILE *wtmp;
+
+ if (!cfg.stamp_utmp)
+ return;
+
+ pw = getpwuid(getuid());
+ location = get_x_display();
+ memset(&utmp_entry, 0, sizeof(utmp_entry));
+ utmp_entry.ut_type = USER_PROCESS;
+ utmp_entry.ut_pid = getpid();
+ strncpy(utmp_entry.ut_line, ttyname+5, lenof(utmp_entry.ut_line));
+ strncpy(utmp_entry.ut_id, ttyname+8, lenof(utmp_entry.ut_id));
+ strncpy(utmp_entry.ut_user, pw->pw_name, lenof(utmp_entry.ut_user));
+ strncpy(utmp_entry.ut_host, location, lenof(utmp_entry.ut_host));
+ time(&utmp_entry.ut_time);
+
+#if defined HAVE_PUTUTLINE
+ utmpname(UTMP_FILE);
+ setutent();
+ pututline(&utmp_entry);
+ endutent();
+#endif
+
+ if ((wtmp = fopen(WTMP_FILE, "a")) != NULL) {
+ fwrite(&utmp_entry, 1, sizeof(utmp_entry), wtmp);
+ fclose(wtmp);
+ }
+
+#ifdef HAVE_LASTLOG
+ memset(&lastlog_entry, 0, sizeof(lastlog_entry));
+ strncpy(lastlog_entry.ll_line, ttyname+5, lenof(lastlog_entry.ll_line));
+ strncpy(lastlog_entry.ll_host, location, lenof(lastlog_entry.ll_host));
+ time(&lastlog_entry.ll_time);
+ if ((lastlog = fopen(LASTLOG_FILE, "r+")) != NULL) {
+ fseek(lastlog, sizeof(lastlog_entry) * getuid(), SEEK_SET);
+ fwrite(&lastlog_entry, 1, sizeof(lastlog_entry), lastlog);
+ fclose(lastlog);
+ }
+#endif
+
+ pty_stamped_utmp = 1;
+
+#endif
+}
+
+static void cleanup_utmp(void)
+{
+#ifndef OMIT_UTMP
+ FILE *wtmp;
+
+ if (!cfg.stamp_utmp || !pty_stamped_utmp)
+ return;
+
+ utmp_entry.ut_type = DEAD_PROCESS;
+ memset(utmp_entry.ut_user, 0, lenof(utmp_entry.ut_user));
+ time(&utmp_entry.ut_time);
+
+ if ((wtmp = fopen(WTMP_FILE, "a")) != NULL) {
+ fwrite(&utmp_entry, 1, sizeof(utmp_entry), wtmp);
+ fclose(wtmp);
+ }
+
+ memset(utmp_entry.ut_line, 0, lenof(utmp_entry.ut_line));
+ utmp_entry.ut_time = 0;
+
+#if defined HAVE_PUTUTLINE
+ utmpname(UTMP_FILE);
+ setutent();
+ pututline(&utmp_entry);
+ endutent();
+#endif
+
+ pty_stamped_utmp = 0; /* ensure we never double-cleanup */
+#endif
+}
+
+static void sigchld_handler(int signum)
+{
+ pid_t pid;
+ int status;
+ pid = waitpid(-1, &status, WNOHANG);
+ if (pid == pty_child_pid && (WIFEXITED(status) || WIFSIGNALED(status)))
+ pty_child_dead = TRUE;
+}
+
+static void fatal_sig_handler(int signum)
+{
+ signal(signum, SIG_DFL);
+ cleanup_utmp();
+ setuid(getuid());
+ raise(signum);
+}
+
/*
* Called to set up the pty.
*
{
int slavefd;
char name[FILENAME_MAX];
- pid_t pid;
+ pid_t pid, pgrp;
+#ifdef BSD_PTYS
+ {
+ const char chars1[] = "pqrstuvwxyz";
+ const char chars2[] = "0123456789abcdef";
+ const char *p1, *p2;
+ char master_name[20];
+
+ for (p1 = chars1; *p1; p1++)
+ for (p2 = chars2; *p2; p2++) {
+ sprintf(master_name, "/dev/pty%c%c", *p1, *p2);
+ pty_master_fd = open(master_name, O_RDWR);
+ if (pty_master_fd >= 0) {
+ if (geteuid() == 0 ||
+ access(master_name, R_OK | W_OK) == 0)
+ goto got_one;
+ close(pty_master_fd);
+ }
+ }
+
+ /* If we get here, we couldn't get a tty at all. */
+ fprintf(stderr, "pterm: unable to open a pseudo-terminal device\n");
+ exit(1);
+
+ got_one:
+ strcpy(name, master_name);
+ name[5] = 't'; /* /dev/ptyXX -> /dev/ttyXX */
+ }
+#else
pty_master_fd = open("/dev/ptmx", O_RDWR);
if (pty_master_fd < 0) {
name[FILENAME_MAX-1] = '\0';
strncpy(name, ptsname(pty_master_fd), FILENAME_MAX-1);
+#endif
- slavefd = open(name, O_RDWR);
- if (slavefd < 0) {
- perror("slave pty: open");
- exit(1);
- }
+ /*
+ * Trap as many fatal signals as we can in the hope of having
+ * the best chance to clean up utmp before termination.
+ */
+ signal(SIGHUP, fatal_sig_handler);
+ signal(SIGINT, fatal_sig_handler);
+ signal(SIGQUIT, fatal_sig_handler);
+ signal(SIGILL, fatal_sig_handler);
+ signal(SIGABRT, fatal_sig_handler);
+ signal(SIGFPE, fatal_sig_handler);
+ signal(SIGPIPE, fatal_sig_handler);
+ signal(SIGALRM, fatal_sig_handler);
+ signal(SIGTERM, fatal_sig_handler);
+ signal(SIGSEGV, fatal_sig_handler);
+ signal(SIGUSR1, fatal_sig_handler);
+ signal(SIGUSR2, fatal_sig_handler);
+#ifdef SIGBUS
+ signal(SIGBUS, fatal_sig_handler);
+#endif
+#ifdef SIGPOLL
+ signal(SIGPOLL, fatal_sig_handler);
+#endif
+#ifdef SIGPROF
+ signal(SIGPROF, fatal_sig_handler);
+#endif
+#ifdef SIGSYS
+ signal(SIGSYS, fatal_sig_handler);
+#endif
+#ifdef SIGTRAP
+ signal(SIGTRAP, fatal_sig_handler);
+#endif
+#ifdef SIGVTALRM
+ signal(SIGVTALRM, fatal_sig_handler);
+#endif
+#ifdef SIGXCPU
+ signal(SIGXCPU, fatal_sig_handler);
+#endif
+#ifdef SIGXFSZ
+ signal(SIGXFSZ, fatal_sig_handler);
+#endif
+#ifdef SIGIO
+ signal(SIGIO, fatal_sig_handler);
+#endif
+ /* Also clean up utmp on normal exit. */
+ atexit(cleanup_utmp);
+ setup_utmp(name);
/*
* Fork and execute the command.
/*
* We are the child.
*/
+
+ slavefd = open(name, O_RDWR);
+ if (slavefd < 0) {
+ perror("slave pty: open");
+ exit(1);
+ }
+
+#ifdef BSD_PTYS
+ /* We need to chown/chmod the /dev/ttyXX device. */
+ {
+ struct group *gp = getgrnam("tty");
+ fchown(slavefd, getuid(), gp ? gp->gr_gid : -1);
+ fchmod(slavefd, 0600);
+ }
+#endif
+
close(pty_master_fd);
close(0);
close(1);
dup2(slavefd, 1);
dup2(slavefd, 2);
setsid();
+ ioctl(slavefd, TIOCSCTTY, 1);
+ pgrp = getpid();
+ tcsetpgrp(slavefd, pgrp);
+ setpgrp();
+ close(open(name, O_WRONLY, 0));
setpgrp();
- tcsetpgrp(0, getpgrp());
+ /* In case we were setgid-utmp or setuid-root, drop privs. */
+ setgid(getgid());
+ setuid(getuid());
/* Close everything _else_, for tidiness. */
for (i = 3; i < 1024; i++)
close(i);
- execl(getenv("SHELL"), getenv("SHELL"), NULL);
+ {
+ char term_env_var[10 + sizeof(cfg.termtype)];
+ sprintf(term_env_var, "TERM=%s", cfg.termtype);
+ putenv(term_env_var);
+ }
+ if (pty_argv)
+ execvp(pty_argv[0], pty_argv);
+ else {
+ char *shell = getenv("SHELL");
+ char *shellname;
+ if (cfg.login_shell) {
+ char *p = strrchr(shell, '/');
+ shellname = smalloc(2+strlen(shell));
+ p = p ? p+1 : shell;
+ sprintf(shellname, "-%s", p);
+ } else
+ shellname = shell;
+ execl(getenv("SHELL"), shellname, NULL);
+ }
+
/*
* If we're here, exec has gone badly foom.
*/
exit(127);
} else {
close(slavefd);
+ pty_child_pid = pid;
+ pty_child_dead = FALSE;
+ signal(SIGCHLD, sigchld_handler);
}
return NULL;