socat/xio-pty.c
2023-11-12 10:57:15 +01:00

255 lines
7.4 KiB
C

/* source: xio-pty.c */
/* Copyright Gerhard Rieger and contributors (see file CHANGES) */
/* Published under the GNU General Public License V.2, see file COPYING */
/* this file contains the source for creating pty addresses */
#include "xiosysincludes.h"
#include "xioopen.h"
#include "xio-named.h"
#include "xio-termios.h"
#if WITH_PTY
/* here define the preferred polling intervall, in seconds */
#define PTY_INTERVALL 1,0 /* for struct timespec */
#define MAXPTYNAMELEN 64
static int xioopen_pty(int argc, const char *argv[], struct opt *opts, int xioflags, xiofile_t *fd, const struct addrdesc *addrdesc);
const struct addrdesc xioaddr_pty = { "PTY", 3, xioopen_pty, GROUP_NAMED|GROUP_FD|GROUP_TERMIOS|GROUP_PTY, 0, 0, 0 HELP("") };
const struct optdesc opt_symbolic_link = { "symbolic-link", "link", OPT_SYMBOLIC_LINK, GROUP_PTY, PH_LATE, TYPE_FILENAME, OFUNC_SPEC, 0, 0 };
#if HAVE_POLL
const struct optdesc opt_pty_wait_slave = { "pty-wait-slave", "wait-slave", OPT_PTY_WAIT_SLAVE, GROUP_PTY, PH_EARLY, TYPE_BOOL, OFUNC_SPEC, 0, 0 };
const struct optdesc opt_pty_intervall = { "pty-interval", NULL, OPT_PTY_INTERVALL, GROUP_PTY, PH_EARLY, TYPE_TIMESPEC, OFUNC_SPEC, 0, 0 };
#endif /* HAVE_POLL */
static int xioopen_pty(
int argc,
const char *argv[],
struct opt *opts,
int xioflags,
xiofile_t *xfd,
const struct addrdesc *addrdesc)
{
/* we expect the form: filename */
struct single *sfd = &xfd->stream;
int ptyfd = -1; /* master */
int ttyfd = -1; /* slave */
#if defined(HAVE_DEV_PTMX) || defined(HAVE_DEV_PTC)
bool useptmx = false; /* use /dev/ptmx or equivalent */
#endif
#if HAVE_OPENPTY
bool useopenpty = false; /* try only openpty */
#endif /* HAVE_OPENPTY */
char ptyname[MAXPTYNAMELEN];
char *tn = NULL;
char *linkname = NULL;
bool opt_unlink_close = true; /* remove symlink afterwards */
bool wait_slave = false; /* true would be better for many platforms, but
some OSes cannot handle this, and for common
default behaviour as well as backward
compatibility we choose "no" as default */
struct timespec pollintv = { PTY_INTERVALL };
if (argc != 1) {
xio_syntax(argv[0], 0, argc-1, addrdesc->syntax);
return STAT_NORETRY;
}
if (sfd->howtoend == END_UNSPEC)
sfd->howtoend = END_CLOSE;
if (applyopts_single(sfd, opts, PH_INIT) < 0) return -1;
applyopts(sfd, -1, opts, PH_INIT);
retropt_bool(opts, OPT_UNLINK_CLOSE, &opt_unlink_close);
/* trying to set user-early, perm-early etc. here might be useless because
file system entry is eventually available only past pty creation */
/* name not yet known; umask should not be handled with this function! */
/* umask does not affect resulting mode, on Linux 2.4 */
applyopts_named("", opts, PH_EARLY); /* umask! */
#if defined(HAVE_DEV_PTMX) || defined(HAVE_DEV_PTC)
retropt_bool(opts, OPT_PTMX, &useptmx);
#endif
#if HAVE_OPENPTY
retropt_bool(opts, OPT_OPENPTY, &useopenpty);
#endif
#if (defined(HAVE_DEV_PTMX) || defined(HAVE_DEV_PTC))
# if HAVE_OPENPTY
useopenpty = !useptmx;
# else /* !HAVE_OPENPTY */
useptmx = true;
# endif /* !HAVE_OPENPTY */
#else
# if HAVE_OPENPTY
useopenpty = true;
# endif /* HAVE_OPENPTY */
#endif /* ! (defined(HAVE_DEV_PTMX) || defined(HAVE_DEV_PTC)) */
#if HAVE_POLL
retropt_bool(opts, OPT_PTY_WAIT_SLAVE, &wait_slave);
retropt_timespec(opts, OPT_PTY_INTERVALL, &pollintv);
#endif /* HAVE_POLL */
if (applyopts_single(sfd, opts, PH_INIT) < 0) return -1;
applyopts2(sfd, -1, opts, PH_INIT, PH_EARLY);
applyopts(sfd, -1, opts, PH_PREBIGEN);
#if HAVE_OPENPTY
if (ptyfd < 0) {
int result;
if ((result = Openpty(&ptyfd, &ttyfd, ptyname, NULL, NULL)) < 0) {
Error4("openpty(%p, %p, %p, NULL, NULL): %s",
&ptyfd, &ttyfd, ptyname, strerror(errno));
return -1;
}
Notice1("PTY is %s", ptyname);
}
#endif /* HAVE_OPENPTY */
#if defined(HAVE_DEV_PTMX)
# define PTMX "/dev/ptmx" /* Linux */
#elif HAVE_DEV_PTC
# define PTMX "/dev/ptc" /* AIX 4.3.3 */
#endif
#if HAVE_DEV_PTMX || HAVE_DEV_PTC
if (useptmx || ptyfd < 0) {
if ((ptyfd = Open(PTMX, O_RDWR|O_NOCTTY, 0620)) < 0) {
Warn1("open(\""PTMX"\", O_RDWR|O_NOCTTY, 0620): %s",
strerror(errno));
/*!*/
} else {
;/*0 Info1("open(\""PTMX"\", O_RDWR|O_NOCTTY, 0620) -> %d", ptyfd);*/
}
if (ptyfd >= 0) {
/* we used PTMX before forking */
/*0 extern char *ptsname(int);*/
#if HAVE_GRANTPT /* AIX, not Linux */
if (Grantpt(ptyfd)/*!*/ < 0) {
Warn2("grantpt(%d): %s", ptyfd, strerror(errno));
}
#endif /* HAVE_GRANTPT */
#if HAVE_UNLOCKPT
if (Unlockpt(ptyfd)/*!*/ < 0) {
Warn2("unlockpt(%d): %s", ptyfd, strerror(errno));
}
#endif /* HAVE_UNLOCKPT */
#if HAVE_PROTOTYPE_LIB_ptsname /* AIX, not Linux */
if ((tn = Ptsname(ptyfd)) == NULL) {
Warn2("ptsname(%d): %s", ptyfd, strerror(errno));
} else {
Notice1("PTY is %s", tn);
}
#endif /* HAVE_PROTOTYPE_LIB_ptsname */
if (tn == NULL) {
if ((tn = Ttyname(ptyfd)) == NULL) {
Warn2("ttyname(%d): %s", ptyfd, strerror(errno));
}
}
ptyname[0] = '\0'; strncat(ptyname, tn, MAXPTYNAMELEN-1);
}
}
#endif /* HAVE_DEV_PTMX || HAVE_DEV_PTC */
if (!retropt_string(opts, OPT_SYMBOLIC_LINK, &linkname)) {
xio_unlink(linkname, E_ERROR);
if (Symlink(ptyname, linkname) < 0) {
Error3("symlink(\"%s\", \"%s\"): %s",
ptyname, linkname, strerror(errno));
}
if (opt_unlink_close) {
if ((sfd->unlink_close = strdup(linkname)) == NULL) {
Error1("strdup(\"%s\"): out of memory", linkname);
}
sfd->opt_unlink_close = true;
}
}
applyopts_named(ptyname, opts, PH_PASTOPEN);
applyopts_named(ptyname, opts, PH_FD);
applyopts_cloexec(ptyfd, opts);/*!*/
sfd->dtype = XIODATA_PTY;
applyopts(sfd, ttyfd, opts, PH_FD);
{
/* special handling of user-late etc.; with standard behaviour (up to
1.7.1.1) they affected /dev/ptmx instead of /dev/pts/N */
uid_t uid = -1, gid = -1;
mode_t perm;
bool dont;
dont = retropt_uid(opts, OPT_USER_LATE, &uid);
dont &= retropt_gid(opts, OPT_GROUP_LATE, &gid);
if (!dont) {
if (Chown(ptyname, uid, gid) < 0) {
Error4("chown(\"%s\", %d, %d): %s",
ptyname, uid, gid, strerror(errno));
}
}
if (retropt_mode(opts, OPT_PERM_LATE, &perm) == 0) {
if (Chmod(ptyname, perm) < 0) {
Error3("chmod(\"%s\", %03o): %s",
ptyname, perm, strerror(errno));
}
}
}
sfd->fd = ptyfd;
applyopts(sfd, -1, opts, PH_LATE);
if (applyopts_single(sfd, opts, PH_LATE) < 0)
return -1;
#if HAVE_POLL
/* if you can and wish: */
if (wait_slave) {
/* try to wait until someone opens the slave side of the pty */
/* we want to get a HUP (hangup) condition on the pty */
#if HAVE_DEV_PTMX || HAVE_DEV_PTC
if (useptmx) {
ttyfd = Open(tn, O_RDWR|O_NOCTTY, 0620);
Close(ttyfd);
}
#endif
#if HAVE_OPENPTY
if (useopenpty) {
Close(ttyfd);
}
#endif /* HAVE_OPENPTY */
/* now we poll until the HUP vanishes - this indicates a slave conn. */
while (true) {
struct pollfd ufd;
ufd.fd = ptyfd;
ufd.events = (POLLHUP);
if (Poll(&ufd, 1, 0) < 0) {
Error3("poll({%d, 0x%04hu,}, 1, 0): %s",
ufd.fd, ufd.events, strerror(errno));
/*! close something */
return -1;
}
if (!(ufd.revents & POLLHUP)) {
break;
}
Nanosleep(&pollintv, NULL);
continue;
}
}
#endif /* HAVE_POLL */
return STAT_OK;
}
#endif /* WITH_PTY */