diff options
Diffstat (limited to 'support')
| -rw-r--r-- | support/Makefile | 1 | ||||
| -rw-r--r-- | support/support_openpty.c | 109 | ||||
| -rw-r--r-- | support/tty.h | 45 |
3 files changed, 155 insertions, 0 deletions
diff --git a/support/Makefile b/support/Makefile index 1bda81e..c632df6 100644 --- a/support/Makefile +++ b/support/Makefile @@ -52,6 +52,7 @@ libsupport-routines = \ support_format_hostent \ support_format_netent \ support_isolate_in_subprocess \ + support_openpty \ support_record_failure \ support_run_diff \ support_shared_allocate \ diff --git a/support/support_openpty.c b/support/support_openpty.c new file mode 100644 index 0000000..ac779ab --- /dev/null +++ b/support/support_openpty.c @@ -0,0 +1,109 @@ +/* Open a pseudoterminal. + Copyright (C) 2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <support/tty.h> +#include <support/check.h> +#include <support/support.h> + +#include <errno.h> +#include <stdlib.h> +#include <string.h> + +#include <fcntl.h> +#include <termios.h> +#include <sys/ioctl.h> +#include <unistd.h> + +/* As ptsname, but allocates space for an appropriately-sized string + using malloc. */ +static char * +xptsname (int fd) +{ + int rv; + size_t buf_len = 128; + char *buf = xmalloc (buf_len); + for (;;) + { + rv = ptsname_r (fd, buf, buf_len); + if (rv) + FAIL_EXIT1 ("ptsname_r: %s", strerror (errno)); + + if (memchr (buf, '\0', buf_len)) + return buf; /* ptsname succeeded and the buffer was not truncated */ + + buf_len *= 2; + buf = xrealloc (buf, buf_len); + } +} + +void +support_openpty (int *a_outer, int *a_inner, char **a_name, + const struct termios *termp, + const struct winsize *winp) +{ + int outer = -1, inner = -1; + char *namebuf = 0; + + outer = posix_openpt (O_RDWR | O_NOCTTY); + if (outer == -1) + FAIL_EXIT1 ("posix_openpt: %s", strerror (errno)); + + if (grantpt (outer)) + FAIL_EXIT1 ("grantpt: %s", strerror (errno)); + + if (unlockpt (outer)) + FAIL_EXIT1 ("unlockpt: %s", strerror (errno)); + + +#ifdef TIOCGPTPEER + inner = ioctl (outer, TIOCGPTPEER, O_RDWR | O_NOCTTY); +#endif + if (inner == -1) + { + /* The kernel might not support TIOCGPTPEER, fall back to open + by name. */ + namebuf = xptsname (outer); + inner = open (namebuf, O_RDWR | O_NOCTTY); + if (inner == -1) + FAIL_EXIT1 ("%s: %s", namebuf, strerror (errno)); + } + + if (termp) + { + if (tcsetattr (inner, TCSAFLUSH, termp)) + FAIL_EXIT1 ("tcsetattr: %s", strerror (errno)); + } +#ifdef TIOCSWINSZ + if (winp) + { + if (ioctl (inner, TIOCSWINSZ, winp)) + FAIL_EXIT1 ("TIOCSWINSZ: %s", strerror (errno)); + } +#endif + + if (a_name) + { + if (!namebuf) + namebuf = xptsname (outer); + *a_name = namebuf; + } + else + free (namebuf); + *a_outer = outer; + *a_inner = inner; +} diff --git a/support/tty.h b/support/tty.h new file mode 100644 index 0000000..1d37c42 --- /dev/null +++ b/support/tty.h @@ -0,0 +1,45 @@ +/* Support functions related to (pseudo)terminals. + Copyright (C) 2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#ifndef _SUPPORT_TTY_H +#define _SUPPORT_TTY_H 1 + +struct termios; +struct winsize; + +/** Open a pseudoterminal pair. The outer fd is written to the address + A_OUTER and the inner fd to A_INNER. + + If A_NAME is not NULL, it will be set to point to a string naming + the /dev/pts/NNN device corresponding to the inner fd; space for + this string is allocated with malloc and should be freed by the + caller when no longer needed. (This is different from the libutil + function 'openpty'.) + + If TERMP is not NULL, the terminal parameters will be initialized + according to the termios structure it points to. + + If WINP is not NULL, the terminal window size will be set + accordingly. + + Terminates the process on failure (like xmalloc). */ +extern void support_openpty (int *a_outer, int *a_inner, char **a_name, + const struct termios *termp, + const struct winsize *winp); + +#endif |