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Rename script_execve to sudo_execve and rename script_foo in exec.c

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This commit is contained in:
Todd C. Miller
2010-05-27 16:46:31 -04:00
parent 4248a11ef7
commit 9773ba3f79
3 changed files with 99 additions and 97 deletions
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190
src/exec.c
View File

@@ -107,17 +107,17 @@ struct io_buffer {
char buf[16 * 1024];
};
static int script_fds[6] = { -1, -1, -1, -1, -1, -1};
static int io_fds[6] = { -1, -1, -1, -1, -1, -1};
static int pipeline = FALSE;
static sig_atomic_t recvsig[NSIG];
static sig_atomic_t ttymode = TERM_COOKED;
static sig_atomic_t tty_initialized = 0;
static sigset_t ttyblock;
static pid_t ppgrp, child;
static int foreground;
static int ttymode = TERM_COOKED;
static int tty_initialized;
static char slavename[PATH_MAX];
@@ -127,23 +127,23 @@ static int perform_io(struct io_buffer *iobufs, fd_set *fdsr, fd_set *fdsw);
static void handler(int s);
static int my_execve(const char *path, char *const argv[],
char *const envp[]);
static int script_child(struct command_details *details, char *argv[],
static int exec_monitor(struct command_details *details, char *argv[],
char *envp[], int, int);
static void script_run(struct command_details *detail, char *argv[],
static void exec_pty(struct command_details *detail, char *argv[],
char *envp[], int);
static void sigwinch(int s);
static void sync_ttysize(int src, int dst);
static void deliver_signal(pid_t pid, int signo);
static int safe_close(int fd);
extern struct user_details user_details; /* XXX */
extern struct user_details user_details; /* XXX need tty name for SELinux */
static void
pty_setup(uid_t uid)
{
script_fds[SFD_USERTTY] = open(_PATH_TTY, O_RDWR|O_NOCTTY, 0);
if (script_fds[SFD_USERTTY] != -1) {
if (!get_pty(&script_fds[SFD_MASTER], &script_fds[SFD_SLAVE],
io_fds[SFD_USERTTY] = open(_PATH_TTY, O_RDWR|O_NOCTTY, 0);
if (io_fds[SFD_USERTTY] != -1) {
if (!get_pty(&io_fds[SFD_MASTER], &io_fds[SFD_SLAVE],
slavename, sizeof(slavename), uid))
error(1, "Can't get pty");
}
@@ -267,12 +267,12 @@ log_stderr(char *buf, unsigned int n)
static void
check_foreground(void)
{
if (script_fds[SFD_USERTTY] != -1) {
foreground = tcgetpgrp(script_fds[SFD_USERTTY]) == ppgrp;
if (io_fds[SFD_USERTTY] != -1) {
foreground = tcgetpgrp(io_fds[SFD_USERTTY]) == ppgrp;
if (foreground && !tty_initialized) {
if (term_copy(script_fds[SFD_USERTTY], script_fds[SFD_SLAVE])) {
if (term_copy(io_fds[SFD_USERTTY], io_fds[SFD_SLAVE])) {
tty_initialized = 1;
sync_ttysize(script_fds[SFD_USERTTY], script_fds[SFD_SLAVE]);
sync_ttysize(io_fds[SFD_USERTTY], io_fds[SFD_SLAVE]);
}
}
}
@@ -300,7 +300,7 @@ suspend_parent(int signo, struct io_buffer *iobufs)
if (foreground) {
if (ttymode != TERM_RAW) {
do {
n = term_raw(script_fds[SFD_USERTTY], 0);
n = term_raw(io_fds[SFD_USERTTY], 0);
} while (!n && errno == EINTR);
ttymode = TERM_RAW;
}
@@ -317,7 +317,7 @@ suspend_parent(int signo, struct io_buffer *iobufs)
/* Restore original tty mode before suspending. */
if (oldmode != TERM_COOKED) {
do {
n = term_restore(script_fds[SFD_USERTTY], 0);
n = term_restore(io_fds[SFD_USERTTY], 0);
} while (!n && errno == EINTR);
}
@@ -341,7 +341,7 @@ suspend_parent(int signo, struct io_buffer *iobufs)
if (foreground) {
/* Set raw mode. */
do {
n = term_raw(script_fds[SFD_USERTTY], 0);
n = term_raw(io_fds[SFD_USERTTY], 0);
} while (!n && errno == EINTR);
} else {
/* Background process, no access to tty. */
@@ -486,7 +486,7 @@ perform_io(struct io_buffer *iobufs, fd_set *fdsr, fd_set *fdsw)
* controlling tty, belongs to child's session but has its own pgrp.
*/
int
script_execve(struct command_details *details, char *argv[], char *envp[],
sudo_execve(struct command_details *details, char *argv[], char *envp[],
struct command_status *cstat)
{
sigaction_t sa;
@@ -510,7 +510,7 @@ script_execve(struct command_details *details, char *argv[], char *envp[],
if (rbac_enabled) {
/* Must do SELinux setup before changing uid. */
selinux_setup(details->selinux_role, details->selinux_type,
log_io ? slavename : user_details.tty, script_fds[SFD_SLAVE]);
log_io ? slavename : user_details.tty, io_fds[SFD_SLAVE]);
}
#endif
@@ -538,7 +538,7 @@ script_execve(struct command_details *details, char *argv[], char *envp[],
sigaction(SIGTERM, &sa, NULL);
if (log_io) {
if (script_fds[SFD_USERTTY] != -1) {
if (io_fds[SFD_USERTTY] != -1) {
sa.sa_flags = SA_RESTART;
sa.sa_handler = sigwinch;
sigaction(SIGWINCH, &sa, NULL);
@@ -555,21 +555,21 @@ script_execve(struct command_details *details, char *argv[], char *envp[],
/*
* Setup stdin/stdout/stderr for child, to be duped after forking.
*/
script_fds[SFD_STDIN] = script_fds[SFD_SLAVE];
script_fds[SFD_STDOUT] = script_fds[SFD_SLAVE];
script_fds[SFD_STDERR] = script_fds[SFD_SLAVE];
io_fds[SFD_STDIN] = io_fds[SFD_SLAVE];
io_fds[SFD_STDOUT] = io_fds[SFD_SLAVE];
io_fds[SFD_STDERR] = io_fds[SFD_SLAVE];
/* Copy /dev/tty -> pty master */
if (script_fds[SFD_USERTTY] != -1) {
iobufs = io_buf_new(script_fds[SFD_USERTTY], script_fds[SFD_MASTER],
if (io_fds[SFD_USERTTY] != -1) {
iobufs = io_buf_new(io_fds[SFD_USERTTY], io_fds[SFD_MASTER],
log_ttyin, iobufs);
/* Copy pty master -> /dev/tty */
iobufs = io_buf_new(script_fds[SFD_MASTER], script_fds[SFD_USERTTY],
iobufs = io_buf_new(io_fds[SFD_MASTER], io_fds[SFD_USERTTY],
log_ttyout, iobufs);
/* Are we the foreground process? */
foreground = tcgetpgrp(script_fds[SFD_USERTTY]) == ppgrp;
foreground = tcgetpgrp(io_fds[SFD_USERTTY]) == ppgrp;
}
/*
@@ -583,7 +583,7 @@ script_execve(struct command_details *details, char *argv[], char *envp[],
error(1, "unable to create pipe");
iobufs = io_buf_new(STDIN_FILENO, io_pipe[STDIN_FILENO][1],
log_stdin, iobufs);
script_fds[SFD_STDIN] = io_pipe[STDIN_FILENO][0];
io_fds[SFD_STDIN] = io_pipe[STDIN_FILENO][0];
}
if (!isatty(STDOUT_FILENO)) {
pipeline = TRUE;
@@ -591,14 +591,14 @@ script_execve(struct command_details *details, char *argv[], char *envp[],
error(1, "unable to create pipe");
iobufs = io_buf_new(io_pipe[STDOUT_FILENO][0], STDOUT_FILENO,
log_stdout, iobufs);
script_fds[SFD_STDOUT] = io_pipe[STDOUT_FILENO][1];
io_fds[SFD_STDOUT] = io_pipe[STDOUT_FILENO][1];
}
if (!isatty(STDERR_FILENO)) {
if (pipe(io_pipe[STDERR_FILENO]) != 0)
error(1, "unable to create pipe");
iobufs = io_buf_new(io_pipe[STDERR_FILENO][0], STDERR_FILENO,
log_stderr, iobufs);
script_fds[SFD_STDERR] = io_pipe[STDERR_FILENO][1];
io_fds[SFD_STDERR] = io_pipe[STDERR_FILENO][1];
}
/* Job control signals to relay from parent to child. */
@@ -612,16 +612,16 @@ script_execve(struct command_details *details, char *argv[], char *envp[],
if (foreground) {
/* Copy terminal attrs from user tty -> pty slave. */
if (term_copy(script_fds[SFD_USERTTY], script_fds[SFD_SLAVE])) {
if (term_copy(io_fds[SFD_USERTTY], io_fds[SFD_SLAVE])) {
tty_initialized = 1;
sync_ttysize(script_fds[SFD_USERTTY], script_fds[SFD_SLAVE]);
sync_ttysize(io_fds[SFD_USERTTY], io_fds[SFD_SLAVE]);
}
/* Start out in raw mode if we are not part of a pipeline. */
if (!pipeline) {
ttymode = TERM_RAW;
do {
n = term_raw(script_fds[SFD_USERTTY], 0);
n = term_raw(io_fds[SFD_USERTTY], 0);
} while (!n && errno == EINTR);
if (!n)
error(1, "Can't set terminal to raw mode");
@@ -642,7 +642,6 @@ script_execve(struct command_details *details, char *argv[], char *envp[],
/* child */
close(sv[0]);
fcntl(sv[1], F_SETFD, FD_CLOEXEC);
/* XXX - defer call to exec_setup() until my_execve()? */
if (exec_setup(details) == TRUE) {
/* headed for execve() */
if (log_io) {
@@ -653,7 +652,7 @@ script_execve(struct command_details *details, char *argv[], char *envp[],
close(io_pipe[STDOUT_FILENO][0]);
if (io_pipe[STDERR_FILENO][0])
close(io_pipe[STDERR_FILENO][0]);
script_child(details, argv, envp, sv[1], rbac_enabled);
exec_monitor(details, argv, envp, sv[1], rbac_enabled);
} else {
if (details->closefrom >= 0)
closefrom(details->closefrom);
@@ -750,12 +749,12 @@ script_execve(struct command_details *details, char *argv[], char *envp[],
}
/* Don't read/write /dev/tty if we are not in the foreground. */
if (iob->rfd != -1 &&
(ttymode == TERM_RAW || iob->rfd != script_fds[SFD_USERTTY])) {
(ttymode == TERM_RAW || iob->rfd != io_fds[SFD_USERTTY])) {
if (iob->len != sizeof(iob->buf))
FD_SET(iob->rfd, fdsr);
}
if (iob->wfd != -1 &&
(foreground || iob->wfd != script_fds[SFD_USERTTY])) {
(foreground || iob->wfd != io_fds[SFD_USERTTY])) {
if (iob->len > iob->off)
FD_SET(iob->wfd, fdsw);
}
@@ -837,18 +836,18 @@ script_execve(struct command_details *details, char *argv[], char *envp[],
if (log_io) {
/* Flush any remaining output (the plugin already got it) */
if (script_fds[SFD_USERTTY] != -1) {
n = fcntl(script_fds[SFD_USERTTY], F_GETFL, 0);
if (io_fds[SFD_USERTTY] != -1) {
n = fcntl(io_fds[SFD_USERTTY], F_GETFL, 0);
if (n != -1 && ISSET(n, O_NONBLOCK)) {
CLR(n, O_NONBLOCK);
(void) fcntl(script_fds[SFD_USERTTY], F_SETFL, n);
(void) fcntl(io_fds[SFD_USERTTY], F_SETFL, n);
}
}
flush_output(iobufs);
if (script_fds[SFD_USERTTY] != -1) {
if (io_fds[SFD_USERTTY] != -1) {
do {
n = term_restore(script_fds[SFD_USERTTY], 0);
n = term_restore(io_fds[SFD_USERTTY], 0);
} while (!n && errno == EINTR);
}
@@ -856,8 +855,8 @@ script_execve(struct command_details *details, char *argv[], char *envp[],
int signo = WTERMSIG(cstat->val);
if (signo && signo != SIGINT && signo != SIGPIPE) {
char *reason = strsignal(signo);
n = script_fds[SFD_USERTTY] != -1 ?
script_fds[SFD_USERTTY] : STDOUT_FILENO;
n = io_fds[SFD_USERTTY] != -1 ?
io_fds[SFD_USERTTY] : STDOUT_FILENO;
write(n, reason, strlen(reason));
if (WCOREDUMP(cstat->val))
write(n, " (core dumped)", 14);
@@ -910,14 +909,14 @@ deliver_signal(pid_t pid, int signo)
case SIGUSR1:
/* foreground process, grant it controlling tty. */
do {
status = tcsetpgrp(script_fds[SFD_SLAVE], pid);
status = tcsetpgrp(io_fds[SFD_SLAVE], pid);
} while (status == -1 && errno == EINTR);
killpg(pid, SIGCONT);
break;
case SIGUSR2:
/* background process, I take controlling tty. */
do {
status = tcsetpgrp(script_fds[SFD_SLAVE], getpid());
status = tcsetpgrp(io_fds[SFD_SLAVE], getpid());
} while (status == -1 && errno == EINTR);
killpg(pid, SIGCONT);
break;
@@ -990,14 +989,14 @@ handle_sigchld(int backchannel, struct command_status *cstat)
}
/*
* Child process that creates a new session with the controlling tty,
* resets signal handlers and forks a child to call script_run().
* Monitor process that creates a new session with the controlling tty,
* resets signal handlers and forks a child to call exec_pty().
* Waits for status changes from the command and relays them to the
* parent and relays signals from the parent to the command.
* Returns an error if fork(2) fails, else calls _exit(2).
*/
int
script_child(struct command_details *details, char *argv[], char *envp[],
exec_monitor(struct command_details *details, char *argv[], char *envp[],
int backchannel, int rbac)
{
struct command_status cstat;
@@ -1008,12 +1007,12 @@ script_child(struct command_details *details, char *argv[], char *envp[],
int alive = TRUE;
/* Close unused fds. */
if (script_fds[SFD_MASTER] != -1)
close(script_fds[SFD_MASTER]);
if (script_fds[SFD_USERTTY] != -1)
close(script_fds[SFD_USERTTY]);
if (io_fds[SFD_MASTER] != -1)
close(io_fds[SFD_MASTER]);
if (io_fds[SFD_USERTTY] != -1)
close(io_fds[SFD_USERTTY]);
/* Reset signal handlers. */
/* Reset SIGWINCH and SIGALRM. */
zero_bytes(&sa, sizeof(sa));
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
@@ -1053,9 +1052,9 @@ script_child(struct command_details *details, char *argv[], char *envp[],
# endif
setpgrp(0, 0);
#endif
if (script_fds[SFD_SLAVE] != -1) {
if (io_fds[SFD_SLAVE] != -1) {
#ifdef TIOCSCTTY
if (ioctl(script_fds[SFD_SLAVE], TIOCSCTTY, NULL) != 0)
if (ioctl(io_fds[SFD_SLAVE], TIOCSCTTY, NULL) != 0)
error(1, "unable to set controlling tty");
#else
/* Set controlling tty by reopening slave. */
@@ -1082,27 +1081,13 @@ script_child(struct command_details *details, char *argv[], char *envp[],
goto bad;
}
if (child == 0) {
/* Reset signal handlers. */
sa.sa_flags = SA_RESTART;
sa.sa_handler = SIG_DFL;
sigaction(SIGHUP, &sa, NULL);
sigaction(SIGTERM, &sa, NULL);
sigaction(SIGINT, &sa, NULL);
sigaction(SIGQUIT, &sa, NULL);
sigaction(SIGTSTP, &sa, NULL);
sigaction(SIGTTIN, &sa, NULL);
sigaction(SIGTTOU, &sa, NULL);
sigaction(SIGUSR1, &sa, NULL);
sigaction(SIGUSR2, &sa, NULL);
sigaction(SIGCHLD, &sa, NULL);
/* We pass errno back to our parent via pipe on exec failure. */
close(backchannel);
close(errpipe[0]);
fcntl(errpipe[1], F_SETFD, FD_CLOEXEC);
/* setup tty and exec command */
script_run(details, argv, envp, rbac);
exec_pty(details, argv, envp, rbac);
cstat.type = CMD_ERRNO;
cstat.val = errno;
write(errpipe[1], &cstat, sizeof(cstat));
@@ -1111,12 +1096,12 @@ script_child(struct command_details *details, char *argv[], char *envp[],
close(errpipe[1]);
/* If any of stdin/stdout/stderr are pipes, close them in parent. */
if (script_fds[SFD_STDIN] != script_fds[SFD_SLAVE])
close(script_fds[SFD_STDIN]);
if (script_fds[SFD_STDOUT] != script_fds[SFD_SLAVE])
close(script_fds[SFD_STDOUT]);
if (script_fds[SFD_STDERR] != script_fds[SFD_SLAVE])
close(script_fds[SFD_STDERR]);
if (io_fds[SFD_STDIN] != io_fds[SFD_SLAVE])
close(io_fds[SFD_STDIN]);
if (io_fds[SFD_STDOUT] != io_fds[SFD_SLAVE])
close(io_fds[SFD_STDOUT]);
if (io_fds[SFD_STDERR] != io_fds[SFD_SLAVE])
close(io_fds[SFD_STDERR]);
/*
* Put child in its own process group. If we are starting the command
@@ -1125,7 +1110,7 @@ script_child(struct command_details *details, char *argv[], char *envp[],
setpgid(child, child);
if (foreground) {
do {
status = tcsetpgrp(script_fds[SFD_SLAVE], child);
status = tcsetpgrp(io_fds[SFD_SLAVE], child);
} while (status == -1 && errno == EINTR);
}
@@ -1239,7 +1224,7 @@ flush_output(struct io_buffer *iobufs)
nwriters = 0;
for (iob = iobufs; iob; iob = iob->next) {
/* Don't read from /dev/tty while flushing. */
if (script_fds[SFD_USERTTY] != -1 && iob->rfd == script_fds[SFD_USERTTY])
if (io_fds[SFD_USERTTY] != -1 && iob->rfd == io_fds[SFD_USERTTY])
continue;
if (iob->rfd == -1 && iob->wfd == -1)
continue;
@@ -1282,38 +1267,55 @@ flush_output(struct io_buffer *iobufs)
}
/*
* Sets up file descriptors and executes the actual command.
* Sets up std{in,out,err} and executes the actual command.
* Returns only if execve() fails.
*/
static void
script_run(struct command_details *details, char *argv[], char *envp[],
exec_pty(struct command_details *details, char *argv[], char *envp[],
int rbac_enabled)
{
sigaction_t sa;
pid_t self = getpid();
/* Reset signal handlers. */
zero_bytes(&sa, sizeof(sa));
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
sa.sa_handler = SIG_DFL;
sigaction(SIGHUP, &sa, NULL);
sigaction(SIGTERM, &sa, NULL);
sigaction(SIGINT, &sa, NULL);
sigaction(SIGQUIT, &sa, NULL);
sigaction(SIGTSTP, &sa, NULL);
sigaction(SIGTTIN, &sa, NULL);
sigaction(SIGTTOU, &sa, NULL);
sigaction(SIGUSR1, &sa, NULL);
sigaction(SIGUSR2, &sa, NULL);
sigaction(SIGCHLD, &sa, NULL);
/* Set child process group here too to avoid a race. */
setpgid(0, self);
/* Wire up standard fds, note that stdout/stderr may be pipes. */
dup2(script_fds[SFD_STDIN], STDIN_FILENO);
dup2(script_fds[SFD_STDOUT], STDOUT_FILENO);
dup2(script_fds[SFD_STDERR], STDERR_FILENO);
dup2(io_fds[SFD_STDIN], STDIN_FILENO);
dup2(io_fds[SFD_STDOUT], STDOUT_FILENO);
dup2(io_fds[SFD_STDERR], STDERR_FILENO);
/* Wait for parent to grant us the tty if we are foreground. */
if (foreground) {
while (tcgetpgrp(script_fds[SFD_SLAVE]) != self)
while (tcgetpgrp(io_fds[SFD_SLAVE]) != self)
; /* spin */
}
/* We have guaranteed that the slave fd is > 2 */
if (script_fds[SFD_SLAVE] != -1)
close(script_fds[SFD_SLAVE]);
if (script_fds[SFD_STDIN] != script_fds[SFD_SLAVE])
close(script_fds[SFD_STDIN]);
if (script_fds[SFD_STDOUT] != script_fds[SFD_SLAVE])
close(script_fds[SFD_STDOUT]);
if (script_fds[SFD_STDERR] != script_fds[SFD_SLAVE])
close(script_fds[SFD_STDERR]);
if (io_fds[SFD_SLAVE] != -1)
close(io_fds[SFD_SLAVE]);
if (io_fds[SFD_STDIN] != io_fds[SFD_SLAVE])
close(io_fds[SFD_STDIN]);
if (io_fds[SFD_STDOUT] != io_fds[SFD_SLAVE])
close(io_fds[SFD_STDOUT]);
if (io_fds[SFD_STDERR] != io_fds[SFD_SLAVE])
close(io_fds[SFD_STDERR]);
if (details->closefrom >= 0)
closefrom(details->closefrom);
@@ -1363,7 +1365,7 @@ sigwinch(int s)
{
int serrno = errno;
sync_ttysize(script_fds[SFD_USERTTY], script_fds[SFD_SLAVE]);
sync_ttysize(io_fds[SFD_USERTTY], io_fds[SFD_SLAVE]);
errno = serrno;
}
@@ -1375,7 +1377,7 @@ static int
safe_close(int fd)
{
/* Avoid closing /dev/tty or std{in,out,err}. */
if (fd < 3 || fd == script_fds[SFD_USERTTY]) {
if (fd < 3 || fd == io_fds[SFD_USERTTY]) {
errno = EINVAL;
return -1;
}

2
src/sudo.c
View File

@@ -792,7 +792,7 @@ run_command(struct command_details *details, char *argv[], char *envp[])
* XXX - no background support
*/
script_execve(details, argv, envp, &cstat);
sudo_execve(details, argv, envp, &cstat);
switch (cstat.type) {
case CMD_ERRNO:

4
src/sudo.h
View File

@@ -157,8 +157,8 @@ int tty_present(void);
/* zero_bytes.c */
void zero_bytes(volatile void *, size_t);
/* script.c */
int script_execve(struct command_details *details, char *argv[], char *envp[],
/* exec.c */
int sudo_execve(struct command_details *details, char *argv[], char *envp[],
struct command_status *cstat);
/* term.c */