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o #define the name "tun" in defs.h against the future possibility

Browse Source 
of supporting architectures with different device names.
o Close /dev/tunX when destroying the bundle.
o Don't forget to close the parent end of the pipe in the child
  process when exec'ing a program from a chat script.
o If we close our controlling terminal, ditch the current session
  with it, allowing getty(8) (or whatever) to regain control.
o After transferring our controlling terminal descriptor to another
  ppp instance, we now fork a new ppp to continue where we left off,
  transferring ownership of all uucp locks and the /var/run/tunX.pid
  file.  Meanwhile the parent closes all file descriptors, defaults
  all signals and does a pause() to wait for a HUP after the
  transferred descriptor is finally closed.
  We don't run /bin/cat any more (again!).

  Suggested by: bde

TODO: It seems clocal devices need their pause()d session leader
      to be given a manual HUP, as closing the last open descriptor
      doesn't do the job.
This commit is contained in:
Brian Somers 1998-05-28 23:17:51 +00:00
parent 46cf264a26
commit 1384bd27d8
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=36452
7 changed files with 170 additions and 117 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

235
usr.sbin/ppp/bundle.c
View File

@ -23,10 +23,10 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: bundle.c,v 1.8 1998/05/25 10:37:00 brian Exp $
* $Id: bundle.c,v 1.9 1998/05/28 23:15:29 brian Exp $
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <net/if.h>
@ -515,7 +515,7 @@ bundle_UpdateSet(struct descriptor *d, fd_set *r, fd_set *w, fd_set *e, int *n)
FD_SET(bundle->dev.fd, r);
if (*n < bundle->dev.fd + 1)
*n = bundle->dev.fd + 1;
log_Printf(LogTIMER, "tun: fdset(r) %d\n", bundle->dev.fd);
log_Printf(LogTIMER, "%s: fdset(r) %d\n", TUN_NAME, bundle->dev.fd);
result++;
}
}
@ -567,12 +567,12 @@ bundle_DescriptorRead(struct descriptor *d, struct bundle *bundle,
/* something to read from tun */
n = read(bundle->dev.fd, &tun, sizeof tun);
if (n < 0) {
log_Printf(LogERROR, "read from tun: %s\n", strerror(errno));
log_Printf(LogERROR, "read from %s: %s\n", TUN_NAME, strerror(errno));
return;
}
n -= sizeof tun - sizeof tun.data;
if (n <= 0) {
log_Printf(LogERROR, "read from tun: Only %d bytes read\n", n);
log_Printf(LogERROR, "read from %s: Only %d bytes read\n", TUN_NAME, n);
return;
}
if (!tun_check_header(tun, AF_INET))
@ -653,6 +653,33 @@ bundle_DescriptorWrite(struct descriptor *d, struct bundle *bundle,
descriptor_Write(&dl->desc, bundle, fdset);
}
static void
bundle_LockTun(struct bundle *bundle)
{
FILE *lockfile;
char pidfile[MAXPATHLEN];
snprintf(pidfile, sizeof pidfile, "%stun%d.pid", _PATH_VARRUN, bundle->unit);
lockfile = ID0fopen(pidfile, "w");
if (lockfile != NULL) {
fprintf(lockfile, "%d\n", (int)getpid());
fclose(lockfile);
}
#ifndef RELEASE_CRUNCH
else
log_Printf(LogERROR, "Warning: Can't create %s: %s\n",
pidfile, strerror(errno));
#endif
}
static void
bundle_UnlockTun(struct bundle *bundle)
{
char pidfile[MAXPATHLEN];
snprintf(pidfile, sizeof pidfile, "%stun%d.pid", _PATH_VARRUN, bundle->unit);
ID0unlink(pidfile);
}
struct bundle *
bundle_Create(const char *prefix, int type)
@ -803,6 +830,8 @@ bundle_Create(const char *prefix, int type)
/* Clean out any leftover crud */
bundle_CleanInterface(&bundle);
bundle_LockTun(&bundle);
return &bundle;
}
@ -854,12 +883,15 @@ bundle_Destroy(struct bundle *bundle)
mp_Down(&bundle->ncp.mp);
ipcp_CleanInterface(&bundle->ncp.ipcp);
bundle_DownInterface(bundle);
/* Again, these are all DATALINK_CLOSED unless we're abending */
dl = bundle->links;
while (dl)
dl = datalink_Destroy(dl);
close(bundle->dev.fd);
bundle_UnlockTun(bundle);
/* In case we never made PHASE_NETWORK */
bundle_Notify(bundle, EX_ERRDEAD);
@ -1432,7 +1464,7 @@ bundle_SendDatalink(struct datalink *dl, int s, struct sockaddr_un *sun)
struct cmsghdr *cmsg = (struct cmsghdr *)cmsgbuf;
struct msghdr msg;
struct iovec iov[SCATTER_SEGMENTS];
int niov, link_fd, f, expect;
int niov, link_fd, f, expect, newsid;
pid_t newpid;
log_Printf(LogPHASE, "Transmitting datalink %s\n", dl->name);
@ -1456,23 +1488,12 @@ bundle_SendDatalink(struct datalink *dl, int s, struct sockaddr_un *sun)
msg.msg_iov = iov;
msg.msg_iovlen = niov;
if (tcgetpgrp(link_fd) == getpgrp()) {
/*
* We can't transfer this tty descriptor. If we do, then once the
* session leader exits, the descriptor becomes unusable by the
* other ppp process. Instead, we'll fork() two `/bin/cat'
* processes.....
*/
msg.msg_control = NULL;
msg.msg_controllen = 0;
} else {
cmsg->cmsg_len = sizeof cmsgbuf;
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
*(int *)CMSG_DATA(cmsg) = link_fd;
msg.msg_control = cmsgbuf;
msg.msg_controllen = sizeof cmsgbuf;
}
cmsg->cmsg_len = sizeof cmsgbuf;
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
*(int *)CMSG_DATA(cmsg) = link_fd;
msg.msg_control = cmsgbuf;
msg.msg_controllen = sizeof cmsgbuf;
for (f = expect = 0; f < niov; f++)
expect += iov[f].iov_len;
@ -1486,69 +1507,10 @@ bundle_SendDatalink(struct datalink *dl, int s, struct sockaddr_un *sun)
/* We must get the ACK before closing the descriptor ! */
read(s, &ack, 1);
if (tcgetpgrp(link_fd) == getpgrp()) {
/* We use `/bin/cat' to keep the tty session id */
pid_t pid;
int status, len, fd;
char name[50], *tname;
tname = ttyname(link_fd);
len = strlen(_PATH_DEV);
if (!strncmp(tname, _PATH_DEV, len))
tname += len;
log_Printf(LogPHASE, "%s: Using twin %s invocations\n", tname, CATPROG);
switch ((pid = fork())) {
case -1:
log_Printf(LogERROR, "fork: %s\n", strerror(errno));
break;
case 0:
if (fork()) /* Don't want to belong to the parent any more */
exit(0);
setsid();
log_Printf(LogPHASE, "%d: Continuing without controlling terminal\n",
(int)getpid());
break;
default:
/* Parent does the execs .... */
timer_TermService();
waitpid(pid, &status, 0);
fcntl(3, F_SETFD, 1); /* Set close-on-exec flag */
fcntl(s, F_SETFL, fcntl(s, F_GETFL, 0) & ~O_NONBLOCK);
fcntl(link_fd, F_SETFL, fcntl(link_fd, F_GETFL, 0) & ~O_NONBLOCK);
s = fcntl(s, F_DUPFD, 3);
link_fd = fcntl(link_fd, F_DUPFD, 3);
dup2(open(_PATH_DEVNULL, O_WRONLY|O_APPEND), STDERR_FILENO);
setuid(geteuid());
switch (fork()) {
case -1:
_exit(0);
break;
case 0:
dup2(link_fd, STDIN_FILENO);
dup2(s, STDOUT_FILENO);
snprintf(name, sizeof name, "%s <- %s", dl->name, tname);
break;
default:
dup2(s, STDIN_FILENO);
dup2(link_fd, STDOUT_FILENO);
snprintf(name, sizeof name, "%s -> %s", dl->name, tname);
break;
}
signal(SIGPIPE, SIG_DFL);
signal(SIGALRM, SIG_DFL);
for (fd = getdtablesize(); fd > 2; fd--)
close(fd);
execl(CATPROG, name, NULL);
_exit(0);
break;
}
}
newsid = tcgetpgrp(link_fd) == getpgrp();
close(link_fd);
if (newsid)
bundle_setsid(dl->bundle, 1);
}
close(s);
@ -1605,3 +1567,104 @@ bundle_SetMode(struct bundle *bundle, struct datalink *dl, int mode)
return 1;
}
void
bundle_setsid(struct bundle *bundle, int holdsession)
{
/*
* Lose the current session. This means getting rid of our pid
* too so that the tty device will really go away, and any getty
* etc will be allowed to restart.
*/
pid_t pid, orig;
int fds[2];
char done;
struct datalink *dl;
orig = getpid();
if (pipe(fds) == -1) {
log_Printf(LogERROR, "pipe: %s\n", strerror(errno));
return;
}
switch ((pid = fork())) {
case -1:
log_Printf(LogERROR, "fork: %s\n", strerror(errno));
close(fds[0]);
close(fds[1]);
return;
case 0:
close(fds[0]);
read(fds[1], &done, 1); /* uu_locks are mine ! */
close(fds[1]);
if (pipe(fds) == -1) {
log_Printf(LogERROR, "pipe(2): %s\n", strerror(errno));
return;
}
switch ((pid = fork())) {
case -1:
log_Printf(LogERROR, "fork: %s\n", strerror(errno));
close(fds[0]);
close(fds[1]);
return;
case 0:
close(fds[0]);
bundle_LockTun(bundle); /* update pid */
read(fds[1], &done, 1); /* uu_locks are mine ! */
close(fds[1]);
setsid();
log_Printf(LogPHASE, "%d -> %d: %s session control\n",
(int)orig, (int)getpid(),
holdsession ? "Passed" : "Dropped");
break;
default:
close(fds[1]);
/* Give away all our modem locks (to the final process) */
for (dl = bundle->links; dl; dl = dl->next)
if (dl->state != DATALINK_CLOSED)
modem_ChangedPid(dl->physical, pid);
write(fds[0], "!", 1); /* done */
close(fds[0]);
exit(0);
break;
}
break;
default:
close(fds[1]);
/* Give away all our modem locks (to the intermediate process) */
for (dl = bundle->links; dl; dl = dl->next)
if (dl->state != DATALINK_CLOSED)
modem_ChangedPid(dl->physical, pid);
write(fds[0], "!", 1); /* done */
close(fds[0]);
if (holdsession) {
int fd, status;
timer_TermService();
signal(SIGPIPE, SIG_DFL);
signal(SIGALRM, SIG_DFL);
signal(SIGHUP, SIG_DFL);
signal(SIGTERM, SIG_DFL);
signal(SIGINT, SIG_DFL);
signal(SIGQUIT, SIG_DFL);
for (fd = getdtablesize(); fd >= 0; fd--)
close(fd);
setuid(geteuid());
/*
* Reap the intermediate process. As we're not exiting but the
* intermediate is, we don't want it to become defunct.
*/
waitpid(pid, &status, 0);
/*
* Hang around for a HUP. This should happen as soon as the
* ppp that we passed our ctty descriptor to closes it.
* NOTE: If this process dies, the passed descriptor becomes
* invalid and will give a select() error by setting one
* of the error fds, aborting the other ppp. We don't
* want that to happen !
*/
pause();
}
exit(0);
break;
}
}

3
usr.sbin/ppp/bundle.h
View File

@ -23,7 +23,7 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: bundle.h,v 1.2 1998/05/21 21:44:14 brian Exp $
* $Id: bundle.h,v 1.3 1998/05/23 22:24:30 brian Exp $
*/
#define PHASE_DEAD 0 /* Link is dead */
@ -164,3 +164,4 @@ extern void bundle_ReceiveDatalink(struct bundle *, int, struct sockaddr_un *);
extern int bundle_SetMode(struct bundle *, struct datalink *, int);
extern int bundle_RenameDatalink(struct bundle *, struct datalink *,
const char *);
extern void bundle_setsid(struct bundle *, int);

4
usr.sbin/ppp/chat.c
View File

@ -23,7 +23,7 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: chat.c,v 1.45 1998/05/21 21:44:37 brian Exp $
* $Id: chat.c,v 1.46 1998/05/23 22:24:32 brian Exp $
*/
#include <sys/types.h>
@ -727,8 +727,8 @@ ExecStr(struct physical *physical, char *command, char *out, int olen)
return;
}
if ((pid = fork()) == 0) {
close(fids[0]);
timer_TermService();
fids[1] = fcntl(fids[1], F_DUPFD, 4);
dup2(physical_GetFD(physical), STDIN_FILENO);
dup2(STDIN_FILENO, STDOUT_FILENO);

6
usr.sbin/ppp/defs.h
View File

@ -15,7 +15,7 @@
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* $Id: defs.h,v 1.29.2.18 1998/05/15 23:58:22 brian Exp $
* $Id: defs.h,v 1.30 1998/05/21 21:45:05 brian Exp $
*
* TODO:
*/
@ -33,8 +33,8 @@
#define _PATH_PPP "/etc/ppp"
#define TUN_PREFIX "/dev/tun" /* tunnel device prefix */
#define CATPROG "/bin/cat" /* Multilink pipe program name */
#define TUN_NAME "tun"
#define TUN_PREFIX (_PATH_DEV TUN_NAME) /* /dev/tun */
#define MODEM_SPEED B38400 /* tty speed */
#define SERVER_PORT 3000 /* Base server port no. */

7
usr.sbin/ppp/log.c
View File

@ -23,7 +23,7 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: log.c,v 1.27 1998/05/21 21:46:25 brian Exp $
* $Id: log.c,v 1.28 1998/05/23 22:24:40 brian Exp $
*/
#include <sys/types.h>
@ -39,6 +39,7 @@
#include "log.h"
#include "descriptor.h"
#include "prompt.h"
#include "defs.h"
static const char *LogNames[] = {
"Async",
@ -293,7 +294,7 @@ log_Printf(int lev, const char *fmt,...)
if ((log_IsKept(lev) & LOG_KEPT_LOCAL) && promptlist) {
if ((log_IsKept(LogTUN) & LOG_KEPT_LOCAL) && LogTunno != -1)
snprintf(nfmt, sizeof nfmt, "tun%d: %s: %s",
snprintf(nfmt, sizeof nfmt, "%s%d: %s: %s", TUN_NAME,
LogTunno, log_Name(lev), fmt);
else
snprintf(nfmt, sizeof nfmt, "%s: %s", log_Name(lev), fmt);
@ -306,7 +307,7 @@ log_Printf(int lev, const char *fmt,...)
if ((log_IsKept(lev) & LOG_KEPT_SYSLOG) &&
(lev != LogWARN || !promptlist)) {
if ((log_IsKept(LogTUN) & LOG_KEPT_SYSLOG) && LogTunno != -1)
snprintf(nfmt, sizeof nfmt, "tun%d: %s: %s",
snprintf(nfmt, sizeof nfmt, "%s%d: %s: %s", TUN_NAME,
LogTunno, log_Name(lev), fmt);
else
snprintf(nfmt, sizeof nfmt, "%s: %s", log_Name(lev), fmt);

21
usr.sbin/ppp/main.c
View File

@ -17,12 +17,12 @@
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* $Id: main.c,v 1.125 1998/05/25 02:22:36 brian Exp $
* $Id: main.c,v 1.126 1998/05/27 22:43:31 brian Exp $
*
* TODO:
*/
#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
@ -78,8 +78,6 @@
#endif
#endif
static char pid_filename[MAXPATHLEN];
static void DoLoop(struct bundle *);
static void TerminalStop(int);
static const char *ex_desc(int);
@ -99,7 +97,6 @@ void
AbortProgram(int excode)
{
server_Close(SignalBundle);
ID0unlink(pid_filename);
log_Printf(LogPHASE, "PPP Terminated (%s).\n", ex_desc(excode));
bundle_Close(SignalBundle, NULL, 1);
bundle_Destroy(SignalBundle);
@ -239,7 +236,6 @@ ProcessArgs(int argc, char **argv, int *mode)
int
main(int argc, char **argv)
{
FILE *lockfile;
char *name, *label;
int nfds, mode;
struct bundle *bundle;
@ -444,19 +440,6 @@ main(int argc, char **argv)
prompt_Required(prompt);
}
snprintf(pid_filename, sizeof pid_filename, "%stun%d.pid",
_PATH_VARRUN, bundle->unit);
lockfile = ID0fopen(pid_filename, "w");
if (lockfile != NULL) {
fprintf(lockfile, "%d\n", (int) getpid());
fclose(lockfile);
}
#ifndef RELEASE_CRUNCH
else
log_Printf(LogALERT, "Warning: Can't create %s: %s\n",
pid_filename, strerror(errno));
#endif
log_Printf(LogPHASE, "PPP Started (%s mode).\n", mode2Nam(mode));
DoLoop(bundle);
AbortProgram(EX_NORMAL);

11
usr.sbin/ppp/modem.c
View File

@ -17,7 +17,7 @@
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* $Id: modem.c,v 1.85 1998/05/25 10:37:02 brian Exp $
* $Id: modem.c,v 1.86 1998/05/28 23:15:38 brian Exp $
*
* TODO:
*/
@ -431,7 +431,7 @@ modem_lock(struct physical *modem, int tunno)
snprintf(fn, sizeof fn, "%s%s.if", _PATH_VARRUN, modem->name.base);
lockfile = ID0fopen(fn, "w");
if (lockfile != NULL) {
fprintf(lockfile, "tun%d\n", tunno);
fprintf(lockfile, "%s%d\n", TUN_NAME, tunno);
fclose(lockfile);
}
#ifndef RELEASE_CRUNCH
@ -750,13 +750,18 @@ modem_Unraw(struct physical *modem)
static void
modem_PhysicalClose(struct physical *modem)
{
int newsid;
log_Printf(LogDEBUG, "%s: Physical Close\n", modem->link.name);
newsid = tcgetpgrp(modem->fd) == getpgrp();
close(modem->fd);
modem->fd = -1;
timer_Stop(&modem->Timer);
log_SetTtyCommandMode(modem->dl);
throughput_stop(&modem->link.throughput);
throughput_log(&modem->link.throughput, LogPHASE, modem->link.name);
if (newsid)
bundle_setsid(modem->dl->bundle, 0);
}
void
@ -1072,7 +1077,7 @@ modem2iov(struct physical *p, struct iovec *iov, int *niov, int maxiov,
void
modem_ChangedPid(struct physical *p, pid_t newpid)
{
if (p->type != PHYS_DIRECT) {
if (p->fd >= 0 && p->type != PHYS_DIRECT) {
int res;
if ((res = ID0uu_lock_txfr(p->name.base, newpid)) != UU_LOCK_OK)