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581c785b | 1 | /* Copyright (C) 1998-2022 Free Software Foundation, Inc. |
6591c335 | 2 | This file is part of the GNU C Library. |
6591c335 UD |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or | |
41bdb6e2 AJ |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either | |
7 | version 2.1 of the License, or (at your option) any later version. | |
6591c335 UD |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
41bdb6e2 | 12 | Lesser General Public License for more details. |
6591c335 | 13 | |
41bdb6e2 | 14 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 | 15 | License along with the GNU C Library; if not, see |
5a82c748 | 16 | <https://www.gnu.org/licenses/>. */ |
6591c335 | 17 | |
00bc5db0 | 18 | #include <errno.h> |
6591c335 | 19 | #include <fcntl.h> |
00bc5db0 | 20 | #include <limits.h> |
6591c335 UD |
21 | #include <pty.h> |
22 | #include <stdlib.h> | |
23 | #include <string.h> | |
24 | #include <termios.h> | |
25 | #include <unistd.h> | |
26 | #include <sys/types.h> | |
734c60eb | 27 | #include <shlib-compat.h> |
6591c335 | 28 | |
00bc5db0 UD |
29 | /* Return the result of ptsname_r in the buffer pointed to by PTS, |
30 | which should be of length BUF_LEN. If it is too long to fit in | |
31 | this buffer, a sufficiently long buffer is allocated using malloc, | |
32 | and returned in PTS. 0 is returned upon success, -1 otherwise. */ | |
33 | static int | |
34 | pts_name (int fd, char **pts, size_t buf_len) | |
35 | { | |
36 | int rv; | |
37 | char *buf = *pts; | |
38 | ||
39 | for (;;) | |
40 | { | |
41 | char *new_buf; | |
42 | ||
43 | if (buf_len) | |
44 | { | |
734c60eb | 45 | rv = __ptsname_r (fd, buf, buf_len); |
00bc5db0 UD |
46 | |
47 | if (rv != 0 || memchr (buf, '\0', buf_len)) | |
48 | /* We either got an error, or we succeeded and the | |
49 | returned name fit in the buffer. */ | |
50 | break; | |
51 | ||
52 | /* Try again with a longer buffer. */ | |
53 | buf_len += buf_len; /* Double it */ | |
54 | } | |
55 | else | |
56 | /* No initial buffer; start out by mallocing one. */ | |
57 | buf_len = 128; /* First time guess. */ | |
58 | ||
59 | if (buf != *pts) | |
60 | /* We've already malloced another buffer at least once. */ | |
61 | new_buf = realloc (buf, buf_len); | |
62 | else | |
63 | new_buf = malloc (buf_len); | |
64 | if (! new_buf) | |
65 | { | |
66 | rv = -1; | |
67 | __set_errno (ENOMEM); | |
68 | break; | |
69 | } | |
70 | buf = new_buf; | |
71 | } | |
72 | ||
73 | if (rv == 0) | |
74 | *pts = buf; /* Return buffer to the user. */ | |
75 | else if (buf != *pts) | |
76 | free (buf); /* Free what we malloced when returning an error. */ | |
77 | ||
78 | return rv; | |
79 | } | |
80 | ||
734c60eb | 81 | /* Create pseudo tty multiplexer/terminal pair and set terminal attributes |
00bc5db0 | 82 | according to TERMP and WINP. Return handles for both ends in |
734c60eb | 83 | *PPTMX and *PTERMINAL, and return the name of the terminal end in NAME. */ |
6591c335 | 84 | int |
734c60eb FW |
85 | __openpty (int *pptmx, int *pterminal, char *name, |
86 | const struct termios *termp, const struct winsize *winp) | |
6591c335 | 87 | { |
00bc5db0 UD |
88 | #ifdef PATH_MAX |
89 | char _buf[PATH_MAX]; | |
90 | #else | |
91 | char _buf[512]; | |
92 | #endif | |
93 | char *buf = _buf; | |
734c60eb | 94 | int ptmx, ret = -1, terminal = -1; |
6591c335 | 95 | |
645ac9aa CB |
96 | *buf = '\0'; |
97 | ||
734c60eb FW |
98 | ptmx = __getpt (); |
99 | if (ptmx == -1) | |
6591c335 UD |
100 | return -1; |
101 | ||
734c60eb | 102 | if (grantpt (ptmx)) |
98e07420 | 103 | goto on_error; |
00bc5db0 | 104 | |
734c60eb | 105 | if (unlockpt (ptmx)) |
98e07420 | 106 | goto on_error; |
6591c335 | 107 | |
645ac9aa | 108 | #ifdef TIOCGPTPEER |
734c60eb FW |
109 | /* Try to allocate terminal fd solely based on PTMX fd first. */ |
110 | terminal = __ioctl (ptmx, TIOCGPTPEER, O_RDWR | O_NOCTTY); | |
645ac9aa | 111 | #endif |
734c60eb | 112 | if (terminal == -1) |
645ac9aa | 113 | { |
734c60eb | 114 | /* Fallback to path-based terminal fd allocation in case kernel doesn't |
645ac9aa CB |
115 | * support TIOCGPTPEER. |
116 | */ | |
734c60eb | 117 | if (pts_name (ptmx, &buf, sizeof (_buf))) |
645ac9aa CB |
118 | goto on_error; |
119 | ||
734c60eb FW |
120 | terminal = __open64 (buf, O_RDWR | O_NOCTTY); |
121 | if (terminal == -1) | |
645ac9aa CB |
122 | goto on_error; |
123 | } | |
6591c335 UD |
124 | |
125 | /* XXX Should we ignore errors here? */ | |
b301e68e | 126 | if (termp) |
734c60eb | 127 | tcsetattr (terminal, TCSAFLUSH, termp); |
b301e68e | 128 | #ifdef TIOCSWINSZ |
00bc5db0 | 129 | if (winp) |
734c60eb | 130 | __ioctl (terminal, TIOCSWINSZ, winp); |
b301e68e | 131 | #endif |
00bc5db0 | 132 | |
734c60eb FW |
133 | *pptmx = ptmx; |
134 | *pterminal = terminal; | |
00bc5db0 | 135 | if (name != NULL) |
645ac9aa CB |
136 | { |
137 | if (*buf == '\0') | |
734c60eb | 138 | if (pts_name (ptmx, &buf, sizeof (_buf))) |
645ac9aa CB |
139 | goto on_error; |
140 | ||
141 | strcpy (name, buf); | |
142 | } | |
6591c335 | 143 | |
98e07420 CB |
144 | ret = 0; |
145 | ||
146 | on_error: | |
147 | if (ret == -1) { | |
734c60eb | 148 | __close (ptmx); |
98e07420 | 149 | |
734c60eb FW |
150 | if (terminal != -1) |
151 | __close (terminal); | |
98e07420 CB |
152 | } |
153 | ||
00bc5db0 UD |
154 | if (buf != _buf) |
155 | free (buf); | |
6d8ec2b1 | 156 | |
98e07420 | 157 | return ret; |
6591c335 | 158 | } |
734c60eb FW |
159 | versioned_symbol (libc, __openpty, openpty, GLIBC_2_34); |
160 | libc_hidden_ver (__openpty, openpty) | |
161 | ||
162 | #if OTHER_SHLIB_COMPAT (libutil, GLIBC_2_0, GLIBC_2_34) | |
163 | compat_symbol (libutil, __openpty, openpty, GLIBC_2_0); | |
164 | #endif |