1 // This is an open source non-commercial project. Dear PVS-Studio, please check
2 // it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
3
4 // Some of the code came from pangoterm and libuv
5 #include <stdbool.h>
6 #include <stdlib.h>
7 #include <string.h>
8 #include <sys/ioctl.h>
9 #include <sys/types.h>
10 #include <sys/wait.h>
11 #include <termios.h>
12
13 // forkpty is not in POSIX, so headers are platform-specific
14 #if defined(__FreeBSD__) || defined(__DragonFly__)
15 # include <libutil.h>
16 #elif defined(__OpenBSD__) || defined(__NetBSD__) || defined(__APPLE__)
17 # include <util.h>
18 #else
19 # include <pty.h>
20 #endif
21
22 #ifdef __APPLE__
23 # include <crt_externs.h>
24 #endif
25
26 #include <uv.h>
27
28 #include "nvim/event/loop.h"
29 #include "nvim/event/process.h"
30 #include "nvim/event/rstream.h"
31 #include "nvim/event/wstream.h"
32 #include "nvim/lib/klist.h"
33 #include "nvim/log.h"
34 #include "nvim/os/os.h"
35 #include "nvim/os/pty_process_unix.h"
36
37 #ifdef INCLUDE_GENERATED_DECLARATIONS
38 # include "os/pty_process_unix.c.generated.h"
39 #endif
40
41 /// termios saved at startup (for TUI) or initialized by pty_process_spawn().
42 static struct termios termios_default;
43
44 /// Saves the termios properties associated with `tty_fd`.
45 ///
46 /// @param tty_fd TTY file descriptor, or -1 if not in a terminal.
pty_process_save_termios(int tty_fd)47 void pty_process_save_termios(int tty_fd)
48 {
49 DLOG("tty_fd=%d", tty_fd);
50 if (tty_fd == -1 || tcgetattr(tty_fd, &termios_default) != 0) {
51 return;
52 }
53 }
54
55 /// @returns zero on success, or negative error code
pty_process_spawn(PtyProcess * ptyproc)56 int pty_process_spawn(PtyProcess *ptyproc)
57 FUNC_ATTR_NONNULL_ALL
58 {
59 if (!termios_default.c_cflag) {
60 // TODO(jkeyes): We could pass NULL to forkpty() instead ...
61 init_termios(&termios_default);
62 }
63
64 int status = 0; // zero or negative error code (libuv convention)
65 Process *proc = (Process *)ptyproc;
66 assert(proc->err.closed);
67 uv_signal_start(&proc->loop->children_watcher, chld_handler, SIGCHLD);
68 ptyproc->winsize = (struct winsize){ ptyproc->height, ptyproc->width, 0, 0 };
69 uv_disable_stdio_inheritance();
70 int master;
71 int pid = forkpty(&master, NULL, &termios_default, &ptyproc->winsize);
72
73 if (pid < 0) {
74 status = -errno;
75 ELOG("forkpty failed: %s", strerror(errno));
76 return status;
77 } else if (pid == 0) {
78 init_child(ptyproc); // never returns
79 }
80
81 // make sure the master file descriptor is non blocking
82 int master_status_flags = fcntl(master, F_GETFL);
83 if (master_status_flags == -1) {
84 status = -errno;
85 ELOG("Failed to get master descriptor status flags: %s", strerror(errno));
86 goto error;
87 }
88 if (fcntl(master, F_SETFL, master_status_flags | O_NONBLOCK) == -1) {
89 status = -errno;
90 ELOG("Failed to make master descriptor non-blocking: %s", strerror(errno));
91 goto error;
92 }
93
94 // Other jobs and providers should not get a copy of this file descriptor.
95 if (os_set_cloexec(master) == -1) {
96 status = -errno;
97 ELOG("Failed to set CLOEXEC on ptmx file descriptor");
98 goto error;
99 }
100
101 if (!proc->in.closed
102 && (status = set_duplicating_descriptor(master, &proc->in.uv.pipe))) {
103 goto error;
104 }
105 if (!proc->out.closed
106 && (status = set_duplicating_descriptor(master, &proc->out.uv.pipe))) {
107 goto error;
108 }
109
110 ptyproc->tty_fd = master;
111 proc->pid = pid;
112 return 0;
113
114 error:
115 close(master);
116 kill(pid, SIGKILL);
117 waitpid(pid, NULL, 0);
118 return status;
119 }
120
pty_process_tty_name(PtyProcess * ptyproc)121 const char *pty_process_tty_name(PtyProcess *ptyproc)
122 {
123 return ptsname(ptyproc->tty_fd);
124 }
125
pty_process_resize(PtyProcess * ptyproc,uint16_t width,uint16_t height)126 void pty_process_resize(PtyProcess *ptyproc, uint16_t width, uint16_t height)
127 FUNC_ATTR_NONNULL_ALL
128 {
129 ptyproc->winsize = (struct winsize){ height, width, 0, 0 };
130 ioctl(ptyproc->tty_fd, TIOCSWINSZ, &ptyproc->winsize);
131 }
132
pty_process_close(PtyProcess * ptyproc)133 void pty_process_close(PtyProcess *ptyproc)
134 FUNC_ATTR_NONNULL_ALL
135 {
136 pty_process_close_master(ptyproc);
137 Process *proc = (Process *)ptyproc;
138 if (proc->internal_close_cb) {
139 proc->internal_close_cb(proc);
140 }
141 }
142
pty_process_close_master(PtyProcess * ptyproc)143 void pty_process_close_master(PtyProcess *ptyproc) FUNC_ATTR_NONNULL_ALL
144 {
145 if (ptyproc->tty_fd >= 0) {
146 close(ptyproc->tty_fd);
147 ptyproc->tty_fd = -1;
148 }
149 }
150
pty_process_teardown(Loop * loop)151 void pty_process_teardown(Loop *loop)
152 {
153 uv_signal_stop(&loop->children_watcher);
154 }
155
init_child(PtyProcess * ptyproc)156 static void init_child(PtyProcess *ptyproc)
157 FUNC_ATTR_NONNULL_ALL
158 {
159 #if defined(HAVE__NSGETENVIRON)
160 # define environ (*_NSGetEnviron())
161 #else
162 extern char **environ;
163 #endif
164 // New session/process-group. #6530
165 setsid();
166
167 signal(SIGCHLD, SIG_DFL);
168 signal(SIGHUP, SIG_DFL);
169 signal(SIGINT, SIG_DFL);
170 signal(SIGQUIT, SIG_DFL);
171 signal(SIGTERM, SIG_DFL);
172 signal(SIGALRM, SIG_DFL);
173
174 Process *proc = (Process *)ptyproc;
175 if (proc->cwd && os_chdir(proc->cwd) != 0) {
176 ELOG("chdir(%s) failed: %s", proc->cwd, strerror(errno));
177 return;
178 }
179
180 char *prog = ptyproc->process.argv[0];
181
182 assert(proc->env);
183 environ = tv_dict_to_env(proc->env);
184 execvp(prog, proc->argv);
185 ELOG("execvp(%s) failed: %s", prog, strerror(errno));
186
187 _exit(122); // 122 is EXEC_FAILED in the Vim source.
188 }
189
init_termios(struct termios * termios)190 static void init_termios(struct termios *termios) FUNC_ATTR_NONNULL_ALL
191 {
192 // Taken from pangoterm
193 termios->c_iflag = ICRNL|IXON;
194 termios->c_oflag = OPOST|ONLCR;
195 #ifdef TAB0
196 termios->c_oflag |= TAB0;
197 #endif
198 termios->c_cflag = CS8|CREAD;
199 termios->c_lflag = ISIG|ICANON|IEXTEN|ECHO|ECHOE|ECHOK;
200
201 cfsetspeed(termios, 38400);
202
203 #ifdef IUTF8
204 termios->c_iflag |= IUTF8;
205 #endif
206 #ifdef NL0
207 termios->c_oflag |= NL0;
208 #endif
209 #ifdef CR0
210 termios->c_oflag |= CR0;
211 #endif
212 #ifdef BS0
213 termios->c_oflag |= BS0;
214 #endif
215 #ifdef VT0
216 termios->c_oflag |= VT0;
217 #endif
218 #ifdef FF0
219 termios->c_oflag |= FF0;
220 #endif
221 #ifdef ECHOCTL
222 termios->c_lflag |= ECHOCTL;
223 #endif
224 #ifdef ECHOKE
225 termios->c_lflag |= ECHOKE;
226 #endif
227
228 termios->c_cc[VINTR] = 0x1f & 'C';
229 termios->c_cc[VQUIT] = 0x1f & '\\';
230 termios->c_cc[VERASE] = 0x7f;
231 termios->c_cc[VKILL] = 0x1f & 'U';
232 termios->c_cc[VEOF] = 0x1f & 'D';
233 termios->c_cc[VEOL] = _POSIX_VDISABLE;
234 termios->c_cc[VEOL2] = _POSIX_VDISABLE;
235 termios->c_cc[VSTART] = 0x1f & 'Q';
236 termios->c_cc[VSTOP] = 0x1f & 'S';
237 termios->c_cc[VSUSP] = 0x1f & 'Z';
238 termios->c_cc[VREPRINT] = 0x1f & 'R';
239 termios->c_cc[VWERASE] = 0x1f & 'W';
240 termios->c_cc[VLNEXT] = 0x1f & 'V';
241 termios->c_cc[VMIN] = 1;
242 termios->c_cc[VTIME] = 0;
243 }
244
set_duplicating_descriptor(int fd,uv_pipe_t * pipe)245 static int set_duplicating_descriptor(int fd, uv_pipe_t *pipe)
246 FUNC_ATTR_NONNULL_ALL
247 {
248 int status = 0; // zero or negative error code (libuv convention)
249 int fd_dup = dup(fd);
250 if (fd_dup < 0) {
251 status = -errno;
252 ELOG("Failed to dup descriptor %d: %s", fd, strerror(errno));
253 return status;
254 }
255
256 if (os_set_cloexec(fd_dup) == -1) {
257 status = -errno;
258 ELOG("Failed to set CLOEXEC on duplicate fd");
259 goto error;
260 }
261
262 status = uv_pipe_open(pipe, fd_dup);
263 if (status) {
264 ELOG("Failed to set pipe to descriptor %d: %s",
265 fd_dup, uv_strerror(status));
266 goto error;
267 }
268 return status;
269
270 error:
271 close(fd_dup);
272 return status;
273 }
274
chld_handler(uv_signal_t * handle,int signum)275 static void chld_handler(uv_signal_t *handle, int signum)
276 {
277 int stat = 0;
278 int pid;
279
280 Loop *loop = handle->loop->data;
281
282 kl_iter(WatcherPtr, loop->children, current) {
283 Process *proc = (*current)->data;
284 do {
285 pid = waitpid(proc->pid, &stat, WNOHANG);
286 } while (pid < 0 && errno == EINTR);
287
288 if (pid <= 0) {
289 continue;
290 }
291
292 if (WIFEXITED(stat)) {
293 proc->status = WEXITSTATUS(stat);
294 } else if (WIFSIGNALED(stat)) {
295 proc->status = 128 + WTERMSIG(stat);
296 }
297 proc->internal_exit_cb(proc);
298 }
299 }
300