1 /*#############################################################################
3 # Pakfire - The IPFire package management system #
4 # Copyright (C) 2022 Pakfire development team #
6 # This program is free software: you can redistribute it and/or modify #
7 # it under the terms of the GNU General Public License as published by #
8 # the Free Software Foundation, either version 3 of the License, or #
9 # (at your option) any later version. #
11 # This program is distributed in the hope that it will be useful, #
12 # but WITHOUT ANY WARRANTY; without even the implied warranty of #
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
14 # GNU General Public License for more details. #
16 # You should have received a copy of the GNU General Public License #
17 # along with this program. If not, see <http://www.gnu.org/licenses/>. #
19 #############################################################################*/
23 #include <linux/capability.h>
24 #include <linux/sched.h>
26 #include <linux/wait.h>
31 #include <sys/capability.h>
32 #include <sys/epoll.h>
33 #include <sys/eventfd.h>
34 #include <sys/mount.h>
35 #include <sys/personality.h>
36 #include <sys/prctl.h>
37 #include <sys/resource.h>
38 #include <sys/timerfd.h>
39 #include <sys/types.h>
45 #include <netlink/route/link.h>
53 #include <pakfire/arch.h>
54 #include <pakfire/cgroup.h>
55 #include <pakfire/jail.h>
56 #include <pakfire/logging.h>
57 #include <pakfire/mount.h>
58 #include <pakfire/pakfire.h>
59 #include <pakfire/path.h>
60 #include <pakfire/private.h>
61 #include <pakfire/pwd.h>
62 #include <pakfire/string.h>
63 #include <pakfire/util.h>
65 #define BUFFER_SIZE 1024 * 64
66 #define ENVIRON_SIZE 128
67 #define EPOLL_MAX_EVENTS 2
68 #define MAX_MOUNTPOINTS 8
70 // The default environment that will be set for every command
71 static const struct environ
{
76 { "LANG", "C.utf-8" },
77 { "PATH", "/usr/local/sbin:/usr/sbin:/sbin:/usr/local/bin:/usr/bin:/bin", },
80 // Tell everything that it is running inside a Pakfire container
81 { "container", "pakfire" },
85 struct pakfire_jail_mountpoint
{
86 char source
[PATH_MAX
];
87 char target
[PATH_MAX
];
92 struct pakfire_ctx
* ctx
;
93 struct pakfire
* pakfire
;
96 // A unique ID for each jail
98 char __uuid
[UUID_STR_LEN
];
104 struct itimerspec timeout
;
107 struct pakfire_cgroup
* cgroup
;
110 char* env
[ENVIRON_SIZE
];
113 struct pakfire_jail_mountpoint mountpoints
[MAX_MOUNTPOINTS
];
114 unsigned int num_mountpoints
;
117 struct pakfire_jail_callbacks
{
119 pakfire_jail_log_callback log
;
124 struct pakfire_log_buffer
{
125 char data
[BUFFER_SIZE
];
129 struct pakfire_jail_exec
{
132 // PID (of the child)
136 // Socket to pass FDs
139 // Process status (from waitid)
142 // FD to notify the client that the parent has finished initialization
146 struct pakfire_jail_pipes
{
152 #endif /* ENABLE_DEBUG */
156 struct pakfire_jail_communicate
{
157 pakfire_jail_communicate_in in
;
158 pakfire_jail_communicate_out out
;
163 struct pakfire_jail_buffers
{
164 struct pakfire_log_buffer stdout
;
165 struct pakfire_log_buffer stderr
;
168 struct pakfire_log_buffer log_INFO
;
169 struct pakfire_log_buffer log_ERROR
;
171 struct pakfire_log_buffer log_DEBUG
;
172 #endif /* ENABLE_DEBUG */
175 struct pakfire_cgroup
* cgroup
;
176 struct pakfire_cgroup_stats cgroup_stats
;
179 struct pakfire_jail_pty
{
180 // The path to the console
181 char console
[PATH_MAX
];
184 struct pakfire_jail_pty_master
{
187 enum pakfire_jail_pty_flags
{
188 PAKFIRE_JAIL_PTY_READY_TO_READ
= (1 << 0),
189 PAKFIRE_JAIL_PTY_READY_TO_WRITE
= (1 << 1),
194 struct pakfire_jail_pty_stdio
{
196 struct pakfire_log_buffer buffer
;
197 struct termios attrs
;
199 enum pakfire_jail_pty_flags flags
;
203 struct pakfire_jail_pty_stdio stdout
;
207 static int clone3(struct clone_args
* args
, size_t size
) {
208 return syscall(__NR_clone3
, args
, size
);
211 static int pidfd_send_signal(int pidfd
, int sig
, siginfo_t
* info
, unsigned int flags
) {
212 return syscall(SYS_pidfd_send_signal
, pidfd
, sig
, info
, flags
);
215 static int pivot_root(const char* new_root
, const char* old_root
) {
216 return syscall(SYS_pivot_root
, new_root
, old_root
);
219 static int pakfire_jail_exec_has_flag(
220 const struct pakfire_jail_exec
* ctx
, const enum pakfire_jail_exec_flags flag
) {
221 return ctx
->flags
& flag
;
224 static void pakfire_jail_free(struct pakfire_jail
* jail
) {
225 DEBUG(jail
->pakfire
, "Freeing jail at %p\n", jail
);
228 for (unsigned int i
= 0; jail
->env
[i
]; i
++)
232 pakfire_cgroup_unref(jail
->cgroup
);
234 pakfire_unref(jail
->pakfire
);
236 pakfire_ctx_unref(jail
->ctx
);
241 Passes any log messages on to the default pakfire log callback
243 static int pakfire_jail_default_log_callback(struct pakfire
* pakfire
, void* data
,
244 int priority
, const char* line
, size_t length
) {
245 struct pakfire_ctx
* ctx
= pakfire_ctx(pakfire
);
247 if (pakfire_ctx_get_log_level(ctx
) >= priority
)
248 pakfire_ctx_log(ctx
, priority
, NULL
, 0, NULL
, "%.*s", (int)length
, line
);
250 pakfire_ctx_unref(ctx
);
255 static const char* pakfire_jail_uuid(struct pakfire_jail
* jail
) {
257 uuid_unparse_lower(jail
->uuid
, jail
->__uuid
);
262 static int pakfire_jail_setup_interactive_env(struct pakfire_jail
* jail
) {
264 int r
= pakfire_jail_set_env(jail
, "PS1", "pakfire-jail \\w> ");
269 char* TERM
= secure_getenv("TERM");
271 r
= pakfire_jail_set_env(jail
, "TERM", TERM
);
277 char* LANG
= secure_getenv("LANG");
279 r
= pakfire_jail_set_env(jail
, "LANG", LANG
);
287 PAKFIRE_EXPORT
int pakfire_jail_create(struct pakfire_jail
** jail
, struct pakfire
* pakfire
) {
290 const char* arch
= pakfire_get_effective_arch(pakfire
);
292 // Allocate a new jail
293 struct pakfire_jail
* j
= calloc(1, sizeof(*j
));
298 j
->ctx
= pakfire_ctx(pakfire
);
301 j
->pakfire
= pakfire_ref(pakfire
);
303 // Initialize reference counter
306 // Generate a random UUID
307 uuid_generate_random(j
->uuid
);
309 DEBUG(j
->pakfire
, "Allocated new jail at %p\n", j
);
311 // Set the default logging callback
312 pakfire_jail_set_log_callback(j
, pakfire_jail_default_log_callback
, NULL
);
314 // Set default environment
315 for (const struct environ
* e
= ENV
; e
->key
; e
++) {
316 r
= pakfire_jail_set_env(j
, e
->key
, e
->val
);
321 // Enable all CPU features that CPU has to offer
322 if (!pakfire_arch_is_supported_by_host(arch
)) {
323 r
= pakfire_jail_set_env(j
, "QEMU_CPU", "max");
328 // Set container UUID
329 r
= pakfire_jail_set_env(j
, "container_uuid", pakfire_jail_uuid(j
));
333 // Disable systemctl to talk to systemd
334 if (!pakfire_on_root(j
->pakfire
)) {
335 r
= pakfire_jail_set_env(j
, "SYSTEMD_OFFLINE", "1");
345 pakfire_jail_free(j
);
350 PAKFIRE_EXPORT
struct pakfire_jail
* pakfire_jail_ref(struct pakfire_jail
* jail
) {
356 PAKFIRE_EXPORT
struct pakfire_jail
* pakfire_jail_unref(struct pakfire_jail
* jail
) {
357 if (--jail
->nrefs
> 0)
360 pakfire_jail_free(jail
);
366 PAKFIRE_EXPORT
void pakfire_jail_set_log_callback(struct pakfire_jail
* jail
,
367 pakfire_jail_log_callback callback
, void* data
) {
368 jail
->callbacks
.log
= callback
;
369 jail
->callbacks
.log_data
= data
;
374 PAKFIRE_EXPORT
int pakfire_jail_nice(struct pakfire_jail
* jail
, int nice
) {
375 // Check if nice level is in range
376 if (nice
< -19 || nice
> 20) {
387 int pakfire_jail_set_cgroup(struct pakfire_jail
* jail
, struct pakfire_cgroup
* cgroup
) {
388 // Free any previous cgroup
390 pakfire_cgroup_unref(jail
->cgroup
);
394 // Set any new cgroup
396 DEBUG(jail
->pakfire
, "Setting cgroup %p\n", cgroup
);
398 jail
->cgroup
= pakfire_cgroup_ref(cgroup
);
407 // Returns the length of the environment
408 static unsigned int pakfire_jail_env_length(struct pakfire_jail
* jail
) {
411 // Count everything in the environment
412 for (char** e
= jail
->env
; *e
; e
++)
418 // Finds an existing environment variable and returns its index or -1 if not found
419 static int pakfire_jail_find_env(struct pakfire_jail
* jail
, const char* key
) {
425 const size_t length
= strlen(key
);
427 for (unsigned int i
= 0; jail
->env
[i
]; i
++) {
428 if ((pakfire_string_startswith(jail
->env
[i
], key
)
429 && *(jail
->env
[i
] + length
) == '=')) {
438 // Returns the value of an environment variable or NULL
439 PAKFIRE_EXPORT
const char* pakfire_jail_get_env(struct pakfire_jail
* jail
,
441 int i
= pakfire_jail_find_env(jail
, key
);
445 return jail
->env
[i
] + strlen(key
) + 1;
448 // Sets an environment variable
449 PAKFIRE_EXPORT
int pakfire_jail_set_env(struct pakfire_jail
* jail
,
450 const char* key
, const char* value
) {
451 // Find the index where to write this value to
452 int i
= pakfire_jail_find_env(jail
, key
);
454 i
= pakfire_jail_env_length(jail
);
456 // Return -ENOSPC when the environment is full
457 if (i
>= ENVIRON_SIZE
) {
462 // Free any previous value
466 // Format and set environment variable
467 asprintf(&jail
->env
[i
], "%s=%s", key
, value
);
469 DEBUG(jail
->pakfire
, "Set environment variable: %s\n", jail
->env
[i
]);
474 // Imports an environment
475 PAKFIRE_EXPORT
int pakfire_jail_import_env(struct pakfire_jail
* jail
, const char* env
[]) {
483 // Copy environment variables
484 for (unsigned int i
= 0; env
[i
]; i
++) {
485 r
= pakfire_string_partition(env
[i
], "=", &key
, &val
);
490 r
= pakfire_jail_set_env(jail
, key
, val
);
507 PAKFIRE_EXPORT
int pakfire_jail_set_timeout(
508 struct pakfire_jail
* jail
, unsigned int timeout
) {
510 jail
->timeout
.it_value
.tv_sec
= timeout
;
513 DEBUG(jail
->pakfire
, "Timeout set to %u second(s)\n", timeout
);
515 DEBUG(jail
->pakfire
, "Timeout disabled\n");
520 static int pakfire_jail_create_timer(struct pakfire_jail
* jail
) {
523 // Nothing to do if no timeout has been set
524 if (!jail
->timeout
.it_value
.tv_sec
)
527 // Create a new timer
528 const int fd
= timerfd_create(CLOCK_MONOTONIC
, 0);
530 ERROR(jail
->pakfire
, "Could not create timer: %m\n");
535 r
= timerfd_settime(fd
, 0, &jail
->timeout
, NULL
);
537 ERROR(jail
->pakfire
, "Could not arm timer: %m\n");
551 This function replaces any logging in the child process.
553 All log messages will be sent to the parent process through their respective pipes.
555 static void pakfire_jail_log_redirect(void* data
, int priority
, const char* file
,
556 int line
, const char* fn
, const char* format
, va_list args
) {
557 struct pakfire_jail_pipes
* pipes
= (struct pakfire_jail_pipes
*)data
;
562 fd
= pipes
->log_INFO
[1];
566 fd
= pipes
->log_ERROR
[1];
571 fd
= pipes
->log_DEBUG
[1];
573 #endif /* ENABLE_DEBUG */
575 // Ignore any messages of an unknown priority
580 // End if we do not have a file descriptor to write to
584 // Optionally log the function name
586 dprintf(fd
, "%s: ", fn
);
588 // Send the log message
589 vdprintf(fd
, format
, args
);
592 static int pakfire_jail_log_buffer_is_full(const struct pakfire_log_buffer
* buffer
) {
593 return (sizeof(buffer
->data
) == buffer
->used
);
596 static int pakfire_jail_fill_buffer(struct pakfire_jail
* jail
, int fd
, struct pakfire_log_buffer
* buffer
) {
599 // Skip this if there is not space left in the buffer
600 if (buffer
->used
>= sizeof(buffer
->data
))
604 r
= read(fd
, buffer
->data
+ buffer
->used
, sizeof(buffer
->data
) - buffer
->used
);
619 // XXX What to do here?
629 static int pakfire_jail_drain_buffer_with_callback(struct pakfire_jail
* jail
,
630 struct pakfire_log_buffer
* buffer
, int priority
, pakfire_jail_communicate_out callback
, void* data
) {
631 const char* eol
= NULL
;
634 while (buffer
->used
) {
635 // Search for the end of the first line
636 eol
= memchr(buffer
->data
, '\n', buffer
->used
);
640 // If the buffer is full, we send the entire content to make space.
641 if (pakfire_jail_log_buffer_is_full(buffer
)) {
642 CTX_DEBUG(jail
->ctx
, "Buffer is full. Sending all content\n");
644 eol
= buffer
->data
+ buffer
->used
- 1;
646 // Otherwise we might have only read parts of the output...
652 // Find the length of the string
653 const size_t length
= eol
- buffer
->data
+ 1;
656 r
= callback(jail
->pakfire
, data
, priority
, buffer
->data
, length
);
658 CTX_ERROR(jail
->ctx
, "The logging callback returned an error: %d\n", r
);
662 // Remove line from buffer
663 memmove(buffer
->data
, buffer
->data
+ length
, buffer
->used
- length
);
664 buffer
->used
-= length
;
670 static int pakfire_jail_drain_buffer(struct pakfire_jail
* jail
, int fd
, struct pakfire_log_buffer
* buffer
) {
673 // Nothing to do if the buffer is empty
677 // Do not try to write to an invalid file descriptor
682 r
= write(fd
, buffer
->data
, buffer
->used
);
697 memmove(buffer
->data
, buffer
->data
+ r
, buffer
->used
- r
);
706 This function reads as much data as it can from the file descriptor.
707 If it finds a whole line in it, it will send it to the logger and repeat the process.
708 If not newline character is found, it will try to read more data until it finds one.
710 static int pakfire_jail_handle_log(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
,
711 int priority
, int fd
, struct pakfire_log_buffer
* buffer
,
712 pakfire_jail_communicate_out callback
, void* data
) {
715 // Fill up buffer from fd
716 r
= pakfire_jail_fill_buffer(jail
, fd
, buffer
);
721 r
= pakfire_jail_drain_buffer_with_callback(jail
, buffer
, priority
, callback
, data
);
728 static int pakfire_jail_stream_stdin(struct pakfire_jail
* jail
,
729 struct pakfire_jail_exec
* ctx
, const int fd
) {
730 const char eof
= 0x04;
733 // Skip if the writing pipe has already been closed
737 CTX_DEBUG(jail
->ctx
, "Streaming standard input...\n");
739 // Calling the callback
740 r
= ctx
->communicate
.in(jail
->pakfire
, ctx
->communicate
.data
, fd
);
744 // The callback signaled that it has written everything
745 CTX_DEBUG(jail
->ctx
, "Closing standard input pipe\n");
748 r
= write(fd
, &eof
, sizeof(eof
));
750 CTX_ERROR(jail
->ctx
, "Could not write EOF: %s\n", strerror(errno
));
757 CTX_DEBUG(jail
->ctx
, "Standard input callback finished\n");
761 CTX_ERROR(jail
->ctx
, "Standard input callback failed: %s\n", strerror(-r
));
766 static int pakfire_jail_recv_fd(struct pakfire_jail
* jail
, int socket
, int* fd
) {
767 const size_t payload_length
= sizeof(fd
);
768 char buffer
[CMSG_SPACE(payload_length
)];
771 struct msghdr msg
= {
772 .msg_control
= buffer
,
773 .msg_controllen
= sizeof(buffer
),
776 // Receive the message
777 r
= recvmsg(socket
, &msg
, 0);
779 CTX_ERROR(jail
->ctx
, "Could not receive file descriptor: %s\n", strerror(errno
));
784 struct cmsghdr
* cmsg
= CMSG_FIRSTHDR(&msg
);
788 *fd
= *((int*)CMSG_DATA(cmsg
));
790 CTX_DEBUG(jail
->ctx
, "Received fd %d from socket %d\n", *fd
, socket
);
795 static int pakfire_jail_send_fd(struct pakfire_jail
* jail
, int socket
, int fd
) {
796 const size_t payload_length
= sizeof(fd
);
797 char buffer
[CMSG_SPACE(payload_length
)];
800 CTX_DEBUG(jail
->ctx
, "Sending fd %d to socket %d\n", fd
, socket
);
803 struct msghdr msg
= {
804 .msg_control
= buffer
,
805 .msg_controllen
= sizeof(buffer
),
809 struct cmsghdr
* cmsg
= CMSG_FIRSTHDR(&msg
);
810 cmsg
->cmsg_level
= SOL_SOCKET
;
811 cmsg
->cmsg_type
= SCM_RIGHTS
;
812 cmsg
->cmsg_len
= CMSG_LEN(payload_length
);
815 *((int*)CMSG_DATA(cmsg
)) = fd
;
818 r
= sendmsg(socket
, &msg
, 0);
820 CTX_ERROR(jail
->ctx
, "Could not send file descriptor: %s\n", strerror(errno
));
827 static int pakfire_jail_setup_pipe(struct pakfire_jail
* jail
, int (*fds
)[2], const int flags
) {
828 int r
= pipe2(*fds
, flags
);
830 ERROR(jail
->pakfire
, "Could not setup pipe: %m\n");
837 static void pakfire_jail_close_pipe(struct pakfire_jail
* jail
, int fds
[2]) {
838 for (unsigned int i
= 0; i
< 2; i
++)
844 This is a convenience function to fetch the reading end of a pipe and
845 closes the write end.
847 static int pakfire_jail_get_pipe_to_read(struct pakfire_jail
* jail
, int (*fds
)[2]) {
848 // Give the variables easier names to avoid confusion
849 int* fd_read
= &(*fds
)[0];
850 int* fd_write
= &(*fds
)[1];
852 // Close the write end of the pipe
853 if (*fd_write
>= 0) {
858 // Return the read end
865 static int pakfire_jail_get_pipe_to_write(struct pakfire_jail
* jail
, int (*fds
)[2]) {
866 // Give the variables easier names to avoid confusion
867 int* fd_read
= &(*fds
)[0];
868 int* fd_write
= &(*fds
)[1];
870 // Close the read end of the pipe
876 // Return the write end
883 static int pakfire_jail_epoll_add_fd(struct pakfire_jail
* jail
, int epollfd
, int fd
, int events
) {
884 struct epoll_event event
= {
885 .events
= events
|EPOLLHUP
,
893 int flags
= fcntl(fd
, F_GETFL
, 0);
895 // Set modified flags
896 r
= fcntl(fd
, F_SETFL
, flags
|O_NONBLOCK
);
898 CTX_ERROR(jail
->ctx
, "Could not set file descriptor %d into non-blocking mode: %s\n",
899 fd
, strerror(errno
));
903 // Add the file descriptor to the loop
904 r
= epoll_ctl(epollfd
, EPOLL_CTL_ADD
, fd
, &event
);
906 ERROR(jail
->pakfire
, "Could not add file descriptor %d to epoll(): %s\n",
907 fd
, strerror(errno
));
916 static int pakfire_jail_enable_raw_mode(struct pakfire_jail
* jail
,
917 struct pakfire_jail_pty_stdio
* stdio
) {
918 struct termios raw_attrs
;
921 // Skip if we don't know the file descriptor
925 // Skip everything if fd is not a TTY
926 if (!isatty(stdio
->fd
))
930 stdio
->fdflags
= fcntl(stdio
->fd
, F_GETFL
);
931 if (stdio
->fdflags
< 0) {
932 CTX_ERROR(jail
->ctx
, "Could not fetch flags from fd %d: %s\n",
933 stdio
->fd
, strerror(errno
));
937 // Fetch all attributes
938 r
= tcgetattr(stdio
->fd
, &stdio
->attrs
);
940 CTX_ERROR(jail
->ctx
, "Could not fetch terminal attributes from fd %d: %s\n",
941 stdio
->fd
, strerror(errno
));
945 // Copy all attributes
946 raw_attrs
= stdio
->attrs
;
949 cfmakeraw(&raw_attrs
);
953 raw_attrs
.c_oflag
= stdio
->attrs
.c_oflag
;
957 raw_attrs
.c_iflag
= stdio
->attrs
.c_iflag
;
958 raw_attrs
.c_lflag
= stdio
->attrs
.c_lflag
;
962 // Restore the attributes
963 r
= tcsetattr(stdio
->fd
, TCSANOW
, &raw_attrs
);
965 CTX_ERROR(jail
->ctx
, "Could not restore terminal attributes for fd %d: %s\n",
966 stdio
->fd
, strerror(errno
));
973 static int pakfire_jail_restore_attrs(struct pakfire_jail
* jail
,
974 const struct pakfire_jail_pty_stdio
* stdio
) {
977 // Skip if we don't know the file descriptor
981 // Skip everything if fd is not a TTY
982 if (!isatty(stdio
->fd
))
986 r
= fcntl(stdio
->fd
, F_SETFL
, stdio
->fdflags
);
988 CTX_ERROR(jail
->ctx
, "Could not set flags for file descriptor %d: %s\n",
989 stdio
->fd
, strerror(errno
));
993 // Restore the attributes
994 r
= tcsetattr(stdio
->fd
, TCSANOW
, &stdio
->attrs
);
996 CTX_ERROR(jail
->ctx
, "Could not restore terminal attributes for %d, ignoring: %s\n",
997 stdio
->fd
, strerror(errno
));
1004 static int pakfire_jail_setup_pty_forwarding(struct pakfire_jail
* jail
,
1005 struct pakfire_jail_exec
* ctx
, const int epollfd
, const int fd
) {
1006 struct winsize size
;
1009 CTX_DEBUG(jail
->ctx
, "Setting up PTY forwarding on fd %d\n", fd
);
1011 // Store the file descriptor
1012 ctx
->pty
.master
.fd
= fd
;
1014 // Add the master to the event loop
1015 r
= pakfire_jail_epoll_add_fd(jail
, epollfd
, ctx
->pty
.master
.fd
, EPOLLIN
|EPOLLOUT
|EPOLLET
);
1019 if (ctx
->flags
& PAKFIRE_JAIL_PTY_FORWARDING
) {
1020 // Configure stdin/stdout
1021 ctx
->pty
.stdin
.fd
= STDIN_FILENO
;
1022 ctx
->pty
.stdout
.fd
= STDOUT_FILENO
;
1025 if (isatty(ctx
->pty
.stdout
.fd
)) {
1026 r
= ioctl(ctx
->pty
.stdout
.fd
, TIOCGWINSZ
, &size
);
1028 CTX_ERROR(jail
->ctx
, "Failed to determine terminal dimensions: %s\n", strerror(errno
));
1033 r
= ioctl(ctx
->pty
.master
.fd
, TIOCSWINSZ
, &size
);
1035 CTX_ERROR(jail
->ctx
, "Failed setting dimensions: %s\n", strerror(errno
));
1040 // Enable RAW mode on standard input
1041 r
= pakfire_jail_enable_raw_mode(jail
, &ctx
->pty
.stdin
);
1045 // Enable RAW mode on standard output
1046 r
= pakfire_jail_enable_raw_mode(jail
, &ctx
->pty
.stdout
);
1050 // Add standard input to the event loop
1051 r
= pakfire_jail_epoll_add_fd(jail
, epollfd
, ctx
->pty
.stdin
.fd
, EPOLLIN
|EPOLLET
);
1055 // Add standard output to the event loop
1056 r
= pakfire_jail_epoll_add_fd(jail
, epollfd
, ctx
->pty
.stdout
.fd
, EPOLLOUT
|EPOLLET
);
1064 static int pakfire_jail_forward_pty(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1067 while (ctx
->pty
.master
.flags
|| ctx
->pty
.stdin
.flags
|| ctx
->pty
.stdout
.flags
) {
1068 // Read from standard input
1069 if (ctx
->pty
.stdin
.flags
& PAKFIRE_JAIL_PTY_READY_TO_READ
) {
1070 r
= pakfire_jail_fill_buffer(jail
, ctx
->pty
.stdin
.fd
, &ctx
->pty
.stdin
.buffer
);
1072 CTX_ERROR(jail
->ctx
, "Failed reading from standard input: %s\n", strerror(-r
));
1076 // We are done reading for now
1077 ctx
->pty
.stdin
.flags
&= ~PAKFIRE_JAIL_PTY_READY_TO_READ
;
1079 // But we may have data to write
1080 if (ctx
->pty
.stdin
.buffer
.used
)
1081 ctx
->pty
.master
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1084 // Write to the master
1085 if (ctx
->pty
.master
.flags
& PAKFIRE_JAIL_PTY_READY_TO_WRITE
) {
1086 if (ctx
->communicate
.in
) {
1087 r
= pakfire_jail_stream_stdin(jail
, ctx
, ctx
->pty
.master
.fd
);
1092 r
= pakfire_jail_drain_buffer(jail
, ctx
->pty
.master
.fd
, &ctx
->pty
.stdin
.buffer
);
1094 CTX_ERROR(jail
->ctx
, "Failed writing to the PTY: %s\n", strerror(-r
));
1099 // We are done writing for now
1100 ctx
->pty
.master
.flags
&= ~PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1103 // Read from the master
1104 if (ctx
->pty
.master
.flags
& PAKFIRE_JAIL_PTY_READY_TO_READ
) {
1105 r
= pakfire_jail_fill_buffer(jail
, ctx
->pty
.master
.fd
, &ctx
->pty
.stdout
.buffer
);
1107 CTX_ERROR(jail
->ctx
, "Failed reading from the PTY: %s\n", strerror(-r
));
1111 // We are done reading for now
1112 ctx
->pty
.master
.flags
&= ~PAKFIRE_JAIL_PTY_READY_TO_READ
;
1114 // But we may have data to write
1115 if (ctx
->pty
.stdout
.buffer
.used
)
1116 ctx
->pty
.stdout
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1119 // Write to standard output
1120 if (ctx
->pty
.stdout
.flags
& PAKFIRE_JAIL_PTY_READY_TO_WRITE
) {
1121 // If we have a callback, we will send any output to the callback
1122 if (ctx
->communicate
.out
) {
1123 r
= pakfire_jail_drain_buffer_with_callback(jail
, &ctx
->pty
.stdout
.buffer
,
1124 LOG_INFO
, ctx
->communicate
.out
, ctx
->communicate
.data
);
1128 // If we have a file descriptor, we will forward any output
1129 } else if (ctx
->pty
.stdout
.fd
>= 0) {
1130 r
= pakfire_jail_drain_buffer(jail
, ctx
->pty
.stdout
.fd
, &ctx
->pty
.stdout
.buffer
);
1132 CTX_ERROR(jail
->ctx
, "Failed writing to standard output: %s\n", strerror(-r
));
1136 // Otherwise send the output to the default logger
1138 r
= pakfire_jail_drain_buffer_with_callback(jail
, &ctx
->pty
.stdout
.buffer
,
1139 LOG_INFO
, pakfire_jail_default_log_callback
, NULL
);
1144 // We are done writing for now
1145 ctx
->pty
.stdout
.flags
&= ~PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1152 static int pakfire_jail_wait(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1154 struct epoll_event events
[EPOLL_MAX_EVENTS
];
1158 // Fetch file descriptors from context
1159 const int pidfd
= ctx
->pidfd
;
1161 // Fetch the UNIX domain socket
1162 const int socket_recv
= pakfire_jail_get_pipe_to_read(jail
, &ctx
->socket
);
1165 const int timerfd
= pakfire_jail_create_timer(jail
);
1168 const int log_INFO
= pakfire_jail_get_pipe_to_read(jail
, &ctx
->pipes
.log_INFO
);
1169 const int log_ERROR
= pakfire_jail_get_pipe_to_read(jail
, &ctx
->pipes
.log_ERROR
);
1171 const int log_DEBUG
= pakfire_jail_get_pipe_to_read(jail
, &ctx
->pipes
.log_DEBUG
);
1172 #endif /* ENABLE_DEBUG */
1174 // Make a list of all file descriptors we are interested in
1175 const struct pakfire_wait_fds
{
1180 { timerfd
, EPOLLIN
},
1183 { ctx
->pidfd
, EPOLLIN
},
1186 { log_INFO
, EPOLLIN
},
1187 { log_ERROR
, EPOLLIN
},
1189 { log_DEBUG
, EPOLLIN
},
1190 #endif /* ENABLE_DEBUG */
1192 // UNIX Domain Socket
1193 { socket_recv
, EPOLLIN
},
1200 epollfd
= epoll_create1(0);
1202 ERROR(jail
->pakfire
, "Could not initialize epoll(): %m\n");
1207 // Turn file descriptors into non-blocking mode and add them to epoll()
1208 for (const struct pakfire_wait_fds
* fd
= fds
; fd
->events
; fd
++) {
1209 // Skip fds which were not initialized
1213 // Add the FD to the event loop
1214 r
= pakfire_jail_epoll_add_fd(jail
, epollfd
, fd
->fd
, fd
->events
);
1221 // Loop for as long as the process is alive
1223 int num
= epoll_wait(epollfd
, events
, EPOLL_MAX_EVENTS
, -1);
1225 // Ignore if epoll_wait() has been interrupted
1229 ERROR(jail
->pakfire
, "epoll_wait() failed: %m\n");
1235 for (int i
= 0; i
< num
; i
++) {
1236 int e
= events
[i
].events
;
1237 int fd
= events
[i
].data
.fd
;
1239 // Handle PTY forwarding events
1240 if (ctx
->pty
.master
.fd
== fd
) {
1241 if (e
& (EPOLLIN
|EPOLLHUP
))
1242 ctx
->pty
.master
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_READ
;
1244 if (e
& (EPOLLOUT
|EPOLLHUP
))
1245 ctx
->pty
.master
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1248 r
= pakfire_jail_forward_pty(jail
, ctx
);
1250 CTX_ERROR(jail
->ctx
, "Failed forwarding the PTY: %s\n", strerror(-r
));
1254 // Handle standard input
1255 } else if (ctx
->pty
.stdin
.fd
== fd
) {
1256 if (e
& (EPOLLIN
|EPOLLHUP
))
1257 ctx
->pty
.stdin
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_READ
;
1260 r
= pakfire_jail_forward_pty(jail
, ctx
);
1262 CTX_ERROR(jail
->ctx
, "Failed forwarding the PTY: %s\n", strerror(-r
));
1266 // Handle standard output
1267 } else if (ctx
->pty
.stdout
.fd
== fd
) {
1268 if (e
& (EPOLLOUT
|EPOLLHUP
))
1269 ctx
->pty
.stdout
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1272 r
= pakfire_jail_forward_pty(jail
, ctx
);
1274 CTX_ERROR(jail
->ctx
, "Failed forwarding the PTY: %s\n", strerror(-r
));
1278 // Handle any changes to the PIDFD
1279 } else if (pidfd
== fd
) {
1281 // Call waidid() and store the result
1282 r
= waitid(P_PIDFD
, ctx
->pidfd
, &ctx
->status
, WEXITED
);
1284 ERROR(jail
->pakfire
, "waitid() failed: %m\n");
1288 // Mark that we have ended so that we will process the remaining
1289 // events from epoll() now, but won't restart the outer loop.
1293 // Handle timer events
1294 } else if (timerfd
== fd
) {
1296 DEBUG(jail
->pakfire
, "Timer event received\n");
1299 r
= read(timerfd
, garbage
, sizeof(garbage
));
1301 ERROR(jail
->pakfire
, "Could not disarm timer: %m\n");
1306 // Terminate the process if it hasn't already ended
1308 DEBUG(jail
->pakfire
, "Terminating process...\n");
1310 // Send SIGTERM to the process
1311 r
= pidfd_send_signal(pidfd
, SIGKILL
, NULL
, 0);
1313 ERROR(jail
->pakfire
, "Could not kill process: %m\n");
1319 // Handle socket messages
1320 } else if (socket_recv
== fd
) {
1322 // Receive the passed FD
1323 r
= pakfire_jail_recv_fd(jail
, socket_recv
, &fd
);
1327 // Setup PTY forwarding
1328 if (ctx
->pty
.master
.fd
< 0) {
1329 r
= pakfire_jail_setup_pty_forwarding(jail
, ctx
, epollfd
, fd
);
1331 CTX_ERROR(jail
->ctx
, "Failed setting up PTY forwarding: %s\n", strerror(-r
));
1337 // Handle log INFO messages
1338 } else if (log_INFO
== fd
) {
1340 r
= pakfire_jail_handle_log(jail
, ctx
, LOG_INFO
, fd
,
1341 &ctx
->buffers
.log_INFO
, pakfire_jail_default_log_callback
, NULL
);
1346 // Handle log ERROR messages
1347 } else if (log_ERROR
== fd
) {
1349 r
= pakfire_jail_handle_log(jail
, ctx
, LOG_ERR
, fd
,
1350 &ctx
->buffers
.log_ERROR
, pakfire_jail_default_log_callback
, NULL
);
1356 // Handle log DEBUG messages
1357 } else if (log_DEBUG
== fd
) {
1359 r
= pakfire_jail_handle_log(jail
, ctx
, LOG_DEBUG
, fd
,
1360 &ctx
->buffers
.log_DEBUG
, pakfire_jail_default_log_callback
, NULL
);
1364 #endif /* ENABLE_DEBUG */
1366 // Log a message for anything else
1368 DEBUG(jail
->pakfire
, "Received invalid file descriptor %d\n", fd
);
1372 // Check if any file descriptors have been closed
1374 // Remove the file descriptor
1375 r
= epoll_ctl(epollfd
, EPOLL_CTL_DEL
, fd
, NULL
);
1377 ERROR(jail
->pakfire
, "Could not remove closed file-descriptor %d: %m\n", fd
);
1390 // Restore any changed terminal attributes
1391 if (ctx
->pty
.stdin
.fd
>= 0)
1392 pakfire_jail_restore_attrs(jail
, &ctx
->pty
.stdin
);
1393 if (ctx
->pty
.stdout
.fd
>= 0)
1394 pakfire_jail_restore_attrs(jail
, &ctx
->pty
.stdout
);
1399 int pakfire_jail_capture_stdout(struct pakfire
* pakfire
, void* data
,
1400 int priority
, const char* line
, size_t length
) {
1401 char** output
= (char**)data
;
1404 // Append everything from stdout to a buffer
1405 if (output
&& priority
== LOG_INFO
) {
1406 r
= asprintf(output
, "%s%.*s", (output
&& *output
) ? *output
: "", (int)length
, line
);
1413 // Send everything else to the default logger
1414 return pakfire_jail_default_log_callback(pakfire
, NULL
, priority
, line
, length
);
1419 // Logs all capabilities of the current process
1420 static int pakfire_jail_show_capabilities(struct pakfire_jail
* jail
) {
1423 cap_flag_value_t value_e
;
1424 cap_flag_value_t value_i
;
1425 cap_flag_value_t value_p
;
1429 pid_t pid
= getpid();
1431 // Fetch all capabilities
1432 caps
= cap_get_proc();
1434 ERROR(jail
->pakfire
, "Could not fetch capabilities: %m\n");
1439 DEBUG(jail
->pakfire
, "Capabilities of PID %d:\n", pid
);
1441 // Iterate over all capabilities
1442 for (unsigned int cap
= 0; cap_valid(cap
); cap
++) {
1443 name
= cap_to_name(cap
);
1445 // Fetch effective value
1446 r
= cap_get_flag(caps
, cap
, CAP_EFFECTIVE
, &value_e
);
1450 // Fetch inheritable value
1451 r
= cap_get_flag(caps
, cap
, CAP_INHERITABLE
, &value_i
);
1455 // Fetch permitted value
1456 r
= cap_get_flag(caps
, cap
, CAP_PERMITTED
, &value_p
);
1460 DEBUG(jail
->pakfire
,
1461 " %-24s : %c%c%c\n",
1463 (value_e
== CAP_SET
) ? 'e' : '-',
1464 (value_i
== CAP_SET
) ? 'i' : '-',
1465 (value_p
== CAP_SET
) ? 'p' : '-'
1485 static int pakfire_jail_set_capabilities(struct pakfire_jail
* jail
) {
1490 // Fetch capabilities
1491 caps
= cap_get_proc();
1493 ERROR(jail
->pakfire
, "Could not read capabilities: %m\n");
1498 // Walk through all capabilities
1499 for (cap_value_t cap
= 0; cap_valid(cap
); cap
++) {
1500 cap_value_t _caps
[] = { cap
};
1502 // Fetch the name of the capability
1503 name
= cap_to_name(cap
);
1505 r
= cap_set_flag(caps
, CAP_EFFECTIVE
, 1, _caps
, CAP_SET
);
1507 ERROR(jail
->pakfire
, "Could not set %s: %m\n", name
);
1511 r
= cap_set_flag(caps
, CAP_INHERITABLE
, 1, _caps
, CAP_SET
);
1513 ERROR(jail
->pakfire
, "Could not set %s: %m\n", name
);
1517 r
= cap_set_flag(caps
, CAP_PERMITTED
, 1, _caps
, CAP_SET
);
1519 ERROR(jail
->pakfire
, "Could not set %s: %m\n", name
);
1528 // Restore all capabilities
1529 r
= cap_set_proc(caps
);
1531 ERROR(jail
->pakfire
, "Restoring capabilities failed: %m\n");
1535 // Add all capabilities to the ambient set
1536 for (unsigned int cap
= 0; cap_valid(cap
); cap
++) {
1537 name
= cap_to_name(cap
);
1539 // Raise the capability
1540 r
= prctl(PR_CAP_AMBIENT
, PR_CAP_AMBIENT_RAISE
, cap
, 0, 0);
1542 ERROR(jail
->pakfire
, "Could not set ambient capability %s: %m\n", name
);
1565 static int pakfire_jail_limit_syscalls(struct pakfire_jail
* jail
) {
1566 const int syscalls
[] = {
1567 // The kernel's keyring isn't namespaced
1570 SCMP_SYS(request_key
),
1572 // Disable userfaultfd
1573 SCMP_SYS(userfaultfd
),
1575 // Disable perf which could leak a lot of information about the host
1576 SCMP_SYS(perf_event_open
),
1582 DEBUG(jail
->pakfire
, "Applying syscall filter...\n");
1584 // Setup a syscall filter which allows everything by default
1585 scmp_filter_ctx ctx
= seccomp_init(SCMP_ACT_ALLOW
);
1587 ERROR(jail
->pakfire
, "Could not setup seccomp filter: %m\n");
1592 for (const int* syscall
= syscalls
; *syscall
; syscall
++) {
1593 r
= seccomp_rule_add(ctx
, SCMP_ACT_ERRNO(EPERM
), *syscall
, 0);
1595 ERROR(jail
->pakfire
, "Could not configure syscall %d: %m\n", *syscall
);
1600 // Load syscall filter into the kernel
1601 r
= seccomp_load(ctx
);
1603 ERROR(jail
->pakfire
, "Could not load syscall filter into the kernel: %m\n");
1609 seccomp_release(ctx
);
1616 PAKFIRE_EXPORT
int pakfire_jail_bind(struct pakfire_jail
* jail
,
1617 const char* source
, const char* target
, int flags
) {
1618 struct pakfire_jail_mountpoint
* mp
= NULL
;
1621 // Check if there is any space left
1622 if (jail
->num_mountpoints
>= MAX_MOUNTPOINTS
) {
1627 // Check for valid inputs
1628 if (!source
|| !target
) {
1633 // Select the next free slot
1634 mp
= &jail
->mountpoints
[jail
->num_mountpoints
];
1637 r
= pakfire_string_set(mp
->source
, source
);
1639 ERROR(jail
->pakfire
, "Could not copy source: %m\n");
1644 r
= pakfire_string_set(mp
->target
, target
);
1646 ERROR(jail
->pakfire
, "Could not copy target: %m\n");
1653 // Increment counter
1654 jail
->num_mountpoints
++;
1659 static int pakfire_jail_mount_networking(struct pakfire_jail
* jail
) {
1662 const char* paths
[] = {
1668 // Bind-mount all paths read-only
1669 for (const char** path
= paths
; *path
; path
++) {
1670 r
= pakfire_bind(jail
->pakfire
, *path
, NULL
, MS_RDONLY
);
1673 // Ignore if we don't have permission
1688 Mounts everything that we require in the new namespace
1690 static int pakfire_jail_mount(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1691 struct pakfire_jail_mountpoint
* mp
= NULL
;
1695 // Enable loop devices
1696 if (pakfire_jail_exec_has_flag(ctx
, PAKFIRE_JAIL_HAS_LOOP_DEVICES
))
1697 flags
|= PAKFIRE_MOUNT_LOOP_DEVICES
;
1699 // Mount all default stuff
1700 r
= pakfire_mount_all(jail
->pakfire
, PAKFIRE_MNTNS_OUTER
, flags
);
1705 r
= pakfire_populate_dev(jail
->pakfire
, flags
);
1709 // Mount the interpreter (if needed)
1710 r
= pakfire_mount_interpreter(jail
->pakfire
);
1714 // Mount networking stuff
1715 if (pakfire_jail_exec_has_flag(ctx
, PAKFIRE_JAIL_HAS_NETWORKING
)) {
1716 r
= pakfire_jail_mount_networking(jail
);
1721 // Mount all custom stuff
1722 for (unsigned int i
= 0; i
< jail
->num_mountpoints
; i
++) {
1724 mp
= &jail
->mountpoints
[i
];
1727 r
= pakfire_bind(jail
->pakfire
, mp
->source
, mp
->target
, mp
->flags
);
1737 static int pakfire_jail_setup_loopback(struct pakfire_jail
* jail
) {
1738 struct nl_sock
* nl
= NULL
;
1739 struct nl_cache
* cache
= NULL
;
1740 struct rtnl_link
* link
= NULL
;
1741 struct rtnl_link
* change
= NULL
;
1744 DEBUG(jail
->pakfire
, "Setting up loopback...\n");
1746 // Allocate a netlink socket
1747 nl
= nl_socket_alloc();
1749 ERROR(jail
->pakfire
, "Could not allocate a netlink socket: %m\n");
1754 // Connect the socket
1755 r
= nl_connect(nl
, NETLINK_ROUTE
);
1757 ERROR(jail
->pakfire
, "Could not connect netlink socket: %s\n", nl_geterror(r
));
1761 // Allocate the netlink cache
1762 r
= rtnl_link_alloc_cache(nl
, AF_UNSPEC
, &cache
);
1764 ERROR(jail
->pakfire
, "Unable to allocate netlink cache: %s\n", nl_geterror(r
));
1768 // Fetch loopback interface
1769 link
= rtnl_link_get_by_name(cache
, "lo");
1771 ERROR(jail
->pakfire
, "Could not find lo interface. Ignoring.\n");
1776 // Allocate a new link
1777 change
= rtnl_link_alloc();
1779 ERROR(jail
->pakfire
, "Could not allocate change link\n");
1784 // Set the link to UP
1785 rtnl_link_set_flags(change
, IFF_UP
);
1787 // Apply any changes
1788 r
= rtnl_link_change(nl
, link
, change
, 0);
1790 ERROR(jail
->pakfire
, "Unable to activate loopback: %s\n", nl_geterror(r
));
1806 static int pakfire_jail_setup_uid_mapping(struct pakfire_jail
* jail
, pid_t pid
) {
1807 char path
[PATH_MAX
];
1810 // Skip mapping anything when running on /
1811 if (pakfire_on_root(jail
->pakfire
))
1815 r
= pakfire_string_format(path
, "/proc/%d/uid_map", pid
);
1820 const uid_t uid
= pakfire_uid(jail
->pakfire
);
1823 const struct pakfire_subid
* subuid
= pakfire_subuid(jail
->pakfire
);
1827 /* When running as root, we will map the entire range.
1829 When running as a non-privileged user, we will map the root user inside the jail
1830 to the user's UID outside of the jail, and we will map the rest starting from one.
1835 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0,
1836 "0 %lu %lu\n", subuid
->id
, subuid
->length
);
1838 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0,
1839 "0 %lu 1\n1 %lu %lu\n", uid
, subuid
->id
, subuid
->length
);
1843 ERROR(jail
->pakfire
, "Could not map UIDs: %m\n");
1850 static int pakfire_jail_setup_gid_mapping(struct pakfire_jail
* jail
, pid_t pid
) {
1851 char path
[PATH_MAX
];
1854 // Skip mapping anything when running on /
1855 if (pakfire_on_root(jail
->pakfire
))
1859 const gid_t gid
= pakfire_gid(jail
->pakfire
);
1862 const struct pakfire_subid
* subgid
= pakfire_subgid(jail
->pakfire
);
1867 r
= pakfire_string_format(path
, "/proc/%d/gid_map", pid
);
1873 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0,
1874 "0 %lu %lu\n", subgid
->id
, subgid
->length
);
1876 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0,
1877 "0 %lu 1\n1 %lu %lu\n", gid
, subgid
->id
, subgid
->length
);
1881 ERROR(jail
->pakfire
, "Could not map GIDs: %m\n");
1888 static int pakfire_jail_setgroups(struct pakfire_jail
* jail
, pid_t pid
) {
1889 char path
[PATH_MAX
];
1893 r
= pakfire_string_format(path
, "/proc/%d/setgroups", pid
);
1897 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0, "deny\n");
1899 CTX_ERROR(jail
->ctx
, "Could not set setgroups to deny: %s\n", strerror(errno
));
1906 static int pakfire_jail_send_signal(struct pakfire_jail
* jail
, int fd
) {
1907 const uint64_t val
= 1;
1910 DEBUG(jail
->pakfire
, "Sending signal...\n");
1912 // Write to the file descriptor
1913 r
= eventfd_write(fd
, val
);
1915 ERROR(jail
->pakfire
, "Could not send signal: %s\n", strerror(errno
));
1919 // Close the file descriptor
1925 static int pakfire_jail_wait_for_signal(struct pakfire_jail
* jail
, int fd
) {
1929 DEBUG(jail
->pakfire
, "Waiting for signal...\n");
1931 r
= eventfd_read(fd
, &val
);
1933 ERROR(jail
->pakfire
, "Error waiting for signal: %s\n", strerror(errno
));
1937 // Close the file descriptor
1944 Performs the initialisation that needs to happen in the parent part
1946 static int pakfire_jail_parent(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1949 // Setup UID mapping
1950 r
= pakfire_jail_setup_uid_mapping(jail
, ctx
->pid
);
1954 // Write "deny" to /proc/PID/setgroups
1955 r
= pakfire_jail_setgroups(jail
, ctx
->pid
);
1959 // Setup GID mapping
1960 r
= pakfire_jail_setup_gid_mapping(jail
, ctx
->pid
);
1964 // Parent has finished initialisation
1965 DEBUG(jail
->pakfire
, "Parent has finished initialization\n");
1967 // Send signal to client
1968 r
= pakfire_jail_send_signal(jail
, ctx
->completed_fd
);
1975 static int pakfire_jail_switch_root(struct pakfire_jail
* jail
, const char* root
) {
1978 // Change to the new root
1981 ERROR(jail
->pakfire
, "chdir(%s) failed: %m\n", root
);
1986 r
= pivot_root(".", ".");
1988 ERROR(jail
->pakfire
, "Failed changing into the new root directory %s: %m\n", root
);
1992 // Umount the old root
1993 r
= umount2(".", MNT_DETACH
);
1995 ERROR(jail
->pakfire
, "Could not umount the old root filesystem: %m\n");
2002 static int pakfire_jail_open_pty(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
2005 // Allocate a new PTY
2006 ctx
->pty
.master
.fd
= posix_openpt(O_RDWR
|O_NONBLOCK
|O_NOCTTY
|O_CLOEXEC
);
2007 if (ctx
->pty
.master
.fd
< 0)
2011 r
= ptsname_r(ctx
->pty
.master
.fd
, ctx
->pty
.console
, sizeof(ctx
->pty
.console
));
2015 CTX_DEBUG(jail
->ctx
, "Allocated console at %s (%d)\n", ctx
->pty
.console
, ctx
->pty
.master
.fd
);
2017 // Unlock the master device
2018 r
= unlockpt(ctx
->pty
.master
.fd
);
2020 CTX_ERROR(jail
->ctx
, "Could not unlock the PTY: %s\n", strerror(errno
));
2025 r
= pakfire_symlink(jail
->ctx
, ctx
->pty
.console
, "/dev/console");
2032 static int pakfire_jail_setup_terminal(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
2036 // Open a new terminal
2037 fd
= open("/dev/console", O_RDWR
|O_NOCTTY
);
2039 CTX_ERROR(jail
->ctx
, "Failed to open a new terminal: %s\n", strerror(errno
));
2043 CTX_DEBUG(jail
->ctx
, "Opened a new terminal %d\n", fd
);
2045 // Connect the new terminal to standard input
2046 r
= dup2(fd
, STDIN_FILENO
);
2048 CTX_ERROR(jail
->ctx
, "Failed to open standard input: %s\n", strerror(errno
));
2052 // Connect the new terminal to standard output
2053 r
= dup2(fd
, STDOUT_FILENO
);
2055 CTX_ERROR(jail
->ctx
, "Failed to open standard output: %s\n", strerror(errno
));
2059 // Connect the new terminal to standard error
2060 r
= dup2(fd
, STDERR_FILENO
);
2062 CTX_ERROR(jail
->ctx
, "Failed to open standard error: %s\n", strerror(errno
));
2069 static int pakfire_jail_child(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
,
2070 const char* argv
[]) {
2073 // Redirect any logging to our log pipe
2074 pakfire_ctx_set_log_callback(jail
->ctx
, pakfire_jail_log_redirect
, &ctx
->pipes
);
2077 pid_t pid
= getpid();
2079 DEBUG(jail
->pakfire
, "Launched child process in jail with PID %d\n", pid
);
2081 // Wait for the parent to finish initialization
2082 r
= pakfire_jail_wait_for_signal(jail
, ctx
->completed_fd
);
2087 r
= prctl(PR_SET_PDEATHSIG
, SIGKILL
, 0, 0, 0);
2089 ERROR(jail
->pakfire
, "Could not configure to die with parent: %m\n");
2093 // Make this process dumpable
2094 r
= prctl (PR_SET_DUMPABLE
, 1, 0, 0, 0);
2096 ERROR(jail
->pakfire
, "Could not make the process dumpable: %m\n");
2100 // Don't drop any capabilities on setuid()
2101 r
= prctl(PR_SET_KEEPCAPS
, 1);
2103 ERROR(jail
->pakfire
, "Could not set PR_SET_KEEPCAPS: %m\n");
2108 uid_t uid
= getuid();
2109 gid_t gid
= getgid();
2112 uid_t euid
= geteuid();
2113 gid_t egid
= getegid();
2115 DEBUG(jail
->pakfire
, " UID: %u (effective %u)\n", uid
, euid
);
2116 DEBUG(jail
->pakfire
, " GID: %u (effective %u)\n", gid
, egid
);
2118 // Log all mountpoints
2119 pakfire_mount_list(jail
->ctx
);
2121 // Fail if we are not PID 1
2123 CTX_ERROR(jail
->ctx
, "Child process is not PID 1\n");
2127 // Fail if we are not running as root
2128 if (uid
|| gid
|| euid
|| egid
) {
2129 ERROR(jail
->pakfire
, "Child process is not running as root\n");
2133 const int socket_send
= pakfire_jail_get_pipe_to_write(jail
, &ctx
->socket
);
2135 // Mount all default stuff
2136 r
= pakfire_mount_all(jail
->pakfire
, PAKFIRE_MNTNS_INNER
, 0);
2140 const char* root
= pakfire_get_path(jail
->pakfire
);
2141 const char* arch
= pakfire_get_effective_arch(jail
->pakfire
);
2143 // Change mount propagation to slave to receive anything from the parent namespace
2144 r
= pakfire_mount_change_propagation(jail
->ctx
, "/", MS_SLAVE
);
2148 // Make root a mountpoint in the new mount namespace
2149 r
= pakfire_mount_make_mounpoint(jail
->pakfire
, root
);
2153 // Change mount propagation to private
2154 r
= pakfire_mount_change_propagation(jail
->ctx
, root
, MS_PRIVATE
);
2158 // Change root (unless root is /)
2159 if (!pakfire_on_root(jail
->pakfire
)) {
2161 r
= pakfire_jail_mount(jail
, ctx
);
2166 r
= pakfire_jail_switch_root(jail
, root
);
2172 unsigned long persona
= pakfire_arch_personality(arch
);
2174 r
= personality(persona
);
2176 ERROR(jail
->pakfire
, "Could not set personality (%x)\n", (unsigned int)persona
);
2182 if (!pakfire_jail_exec_has_flag(ctx
, PAKFIRE_JAIL_HAS_NETWORKING
)) {
2183 r
= pakfire_jail_setup_loopback(jail
);
2190 DEBUG(jail
->pakfire
, "Setting nice level to %d\n", jail
->nice
);
2192 r
= setpriority(PRIO_PROCESS
, pid
, jail
->nice
);
2194 ERROR(jail
->pakfire
, "Could not set nice level: %m\n");
2199 // Create a new session
2202 CTX_ERROR(jail
->ctx
, "Could not create a new session: %s\n", strerror(errno
));
2206 // Allocate a new PTY
2207 r
= pakfire_jail_open_pty(jail
, ctx
);
2209 CTX_ERROR(jail
->ctx
, "Could not allocate a new PTY: %s\n", strerror(-r
));
2213 // Send the PTY master to the parent process
2214 r
= pakfire_jail_send_fd(jail
, socket_send
, ctx
->pty
.master
.fd
);
2216 CTX_ERROR(jail
->ctx
, "Failed sending the PTY master to the parent: %s\n", strerror(-r
));
2220 // Setup the terminal
2221 r
= pakfire_jail_setup_terminal(jail
, ctx
);
2225 // Close the master of the PTY
2226 close(ctx
->pty
.master
.fd
);
2227 ctx
->pty
.master
.fd
= -1;
2232 // Close other end of log pipes
2233 close(ctx
->pipes
.log_INFO
[0]);
2234 close(ctx
->pipes
.log_ERROR
[0]);
2236 close(ctx
->pipes
.log_DEBUG
[0]);
2237 #endif /* ENABLE_DEBUG */
2239 // Reset open file limit (http://0pointer.net/blog/file-descriptor-limits.html)
2240 r
= pakfire_rlimit_reset_nofile(jail
->pakfire
);
2245 r
= pakfire_jail_set_capabilities(jail
);
2249 // Show capabilities
2250 r
= pakfire_jail_show_capabilities(jail
);
2255 r
= pakfire_jail_limit_syscalls(jail
);
2259 DEBUG(jail
->pakfire
, "Child process initialization done\n");
2260 DEBUG(jail
->pakfire
, "Launching command:\n");
2263 for (unsigned int i
= 0; argv
[i
]; i
++)
2264 DEBUG(jail
->pakfire
, " argv[%u] = %s\n", i
, argv
[i
]);
2267 r
= execvpe(argv
[0], (char**)argv
, jail
->env
);
2269 // Translate errno into regular exit code
2272 // Ignore if the command doesn't exist
2273 if (ctx
->flags
& PAKFIRE_JAIL_NOENT_OK
)
2284 ERROR(jail
->pakfire
, "Could not execve(%s): %m\n", argv
[0]);
2287 // We should not get here
2291 // Run a command in the jail
2292 static int __pakfire_jail_exec(struct pakfire_jail
* jail
, const char* argv
[],
2293 pakfire_jail_communicate_in communicate_in
,
2294 pakfire_jail_communicate_out communicate_out
,
2295 void* data
, int flags
) {
2299 // Check if argv is valid
2300 if (!argv
|| !argv
[0]) {
2305 // Initialize context for this call
2306 struct pakfire_jail_exec ctx
= {
2309 .socket
= { -1, -1 },
2312 .log_INFO
= { -1, -1 },
2313 .log_ERROR
= { -1, -1 },
2315 .log_DEBUG
= { -1, -1 },
2316 #endif /* ENABLE_DEBUG */
2320 .in
= communicate_in
,
2321 .out
= communicate_out
,
2341 DEBUG(jail
->pakfire
, "Executing jail...\n");
2343 // Enable networking in interactive mode
2344 if (ctx
.flags
& PAKFIRE_JAIL_PTY_FORWARDING
)
2345 ctx
.flags
|= PAKFIRE_JAIL_HAS_NETWORKING
;
2348 Setup a file descriptor which can be used to notify the client that the parent
2349 has completed configuration.
2351 ctx
.completed_fd
= eventfd(0, EFD_CLOEXEC
);
2352 if (ctx
.completed_fd
< 0) {
2353 ERROR(jail
->pakfire
, "eventfd() failed: %m\n");
2357 // Create a UNIX domain socket
2358 r
= socketpair(AF_UNIX
, SOCK_DGRAM
|SOCK_CLOEXEC
, 0, ctx
.socket
);
2360 CTX_ERROR(jail
->ctx
, "Could not create UNIX socket: %s\n", strerror(errno
));
2365 // Setup pipes for logging
2367 r
= pakfire_jail_setup_pipe(jail
, &ctx
.pipes
.log_INFO
, O_CLOEXEC
);
2372 r
= pakfire_jail_setup_pipe(jail
, &ctx
.pipes
.log_ERROR
, O_CLOEXEC
);
2378 r
= pakfire_jail_setup_pipe(jail
, &ctx
.pipes
.log_DEBUG
, O_CLOEXEC
);
2381 #endif /* ENABLE_DEBUG */
2383 // Configure child process
2384 struct clone_args args
= {
2394 .exit_signal
= SIGCHLD
,
2395 .pidfd
= (long long unsigned int)&ctx
.pidfd
,
2398 // Launch the process in a cgroup that is a leaf of the configured cgroup
2400 args
.flags
|= CLONE_INTO_CGROUP
;
2403 const char* uuid
= pakfire_jail_uuid(jail
);
2405 // Create a temporary cgroup
2406 r
= pakfire_cgroup_child(&ctx
.cgroup
, jail
->cgroup
, uuid
, 0);
2408 ERROR(jail
->pakfire
, "Could not create cgroup for jail: %m\n");
2412 // Clone into this cgroup
2413 args
.cgroup
= pakfire_cgroup_fd(ctx
.cgroup
);
2417 if (!pakfire_jail_exec_has_flag(&ctx
, PAKFIRE_JAIL_HAS_NETWORKING
)) {
2418 args
.flags
|= CLONE_NEWNET
;
2421 // Fork this process
2422 ctx
.pid
= clone3(&args
, sizeof(args
));
2424 ERROR(jail
->pakfire
, "Could not clone: %m\n");
2428 } else if (ctx
.pid
== 0) {
2429 r
= pakfire_jail_child(jail
, &ctx
, argv
);
2434 r
= pakfire_jail_parent(jail
, &ctx
);
2438 DEBUG(jail
->pakfire
, "Waiting for PID %d to finish its work\n", ctx
.pid
);
2440 // Read output of the child process
2441 r
= pakfire_jail_wait(jail
, &ctx
);
2445 // Handle exit status
2446 switch (ctx
.status
.si_code
) {
2448 DEBUG(jail
->pakfire
, "The child process exited with code %d\n",
2449 ctx
.status
.si_status
);
2452 exit
= ctx
.status
.si_status
;
2456 ERROR(jail
->pakfire
, "The child process was killed\n");
2461 ERROR(jail
->pakfire
, "The child process terminated abnormally\n");
2464 // Log anything else
2466 ERROR(jail
->pakfire
, "Unknown child exit code: %d\n", ctx
.status
.si_code
);
2471 // Destroy the temporary cgroup (if any)
2473 // Read cgroup stats
2474 pakfire_cgroup_stat(ctx
.cgroup
, &ctx
.cgroup_stats
);
2475 pakfire_cgroup_stat_dump(ctx
.cgroup
, &ctx
.cgroup_stats
);
2476 pakfire_cgroup_destroy(ctx
.cgroup
);
2477 pakfire_cgroup_unref(ctx
.cgroup
);
2480 // Close any file descriptors
2483 if (ctx
.pty
.master
.fd
>= 0)
2484 close(ctx
.pty
.master
.fd
);
2485 pakfire_jail_close_pipe(jail
, ctx
.pipes
.log_INFO
);
2486 pakfire_jail_close_pipe(jail
, ctx
.pipes
.log_ERROR
);
2488 pakfire_jail_close_pipe(jail
, ctx
.pipes
.log_DEBUG
);
2489 #endif /* ENABLE_DEBUG */
2490 pakfire_jail_close_pipe(jail
, ctx
.socket
);
2495 PAKFIRE_EXPORT
int pakfire_jail_exec(
2496 struct pakfire_jail
* jail
,
2498 pakfire_jail_communicate_in callback_in
,
2499 pakfire_jail_communicate_out callback_out
,
2500 void* data
, int flags
) {
2501 return __pakfire_jail_exec(jail
, argv
, callback_in
, callback_out
, data
, flags
);
2504 static int pakfire_jail_exec_interactive(
2505 struct pakfire_jail
* jail
, const char* argv
[], int flags
) {
2508 flags
|= PAKFIRE_JAIL_PTY_FORWARDING
;
2510 // Setup interactive stuff
2511 r
= pakfire_jail_setup_interactive_env(jail
);
2515 return __pakfire_jail_exec(jail
, argv
, NULL
, NULL
, NULL
, flags
);
2518 int pakfire_jail_exec_script(struct pakfire_jail
* jail
,
2522 pakfire_jail_communicate_in callback_in
,
2523 pakfire_jail_communicate_out callback_out
,
2525 char path
[PATH_MAX
];
2526 const char** argv
= NULL
;
2530 const char* root
= pakfire_get_path(jail
->pakfire
);
2532 // Write the scriptlet to disk
2533 r
= pakfire_path_append(path
, root
, PAKFIRE_TMP_DIR
"/pakfire-script.XXXXXX");
2537 // Create a temporary file
2538 f
= pakfire_mktemp(path
, 0700);
2540 ERROR(jail
->pakfire
, "Could not create temporary file: %m\n");
2544 DEBUG(jail
->pakfire
, "Writing script to %s:\n%.*s\n", path
, (int)size
, script
);
2547 r
= fprintf(f
, "%s", script
);
2549 ERROR(jail
->pakfire
, "Could not write script to file %s: %m\n", path
);
2556 ERROR(jail
->pakfire
, "Could not close script file %s: %m\n", path
);
2562 // Count how many arguments were passed
2563 unsigned int argc
= 1;
2565 for (const char** arg
= args
; *arg
; arg
++)
2569 argv
= calloc(argc
+ 1, sizeof(*argv
));
2571 ERROR(jail
->pakfire
, "Could not allocate argv: %m\n");
2576 argv
[0] = (root
) ? pakfire_path_relpath(root
, path
) : path
;
2579 for (unsigned int i
= 1; i
< argc
; i
++)
2580 argv
[i
] = args
[i
-1];
2583 r
= pakfire_jail_exec(jail
, argv
, callback_in
, callback_out
, data
, 0);
2591 // Remove script from disk
2599 A convenience function that creates a new jail, runs the given command and destroys
2602 int pakfire_jail_run(struct pakfire
* pakfire
, const char* argv
[], int flags
, char** output
) {
2603 struct pakfire_jail
* jail
= NULL
;
2606 // Create a new jail
2607 r
= pakfire_jail_create(&jail
, pakfire
);
2611 // Execute the command
2612 r
= pakfire_jail_exec(jail
, argv
, NULL
, pakfire_jail_capture_stdout
, output
, 0);
2616 pakfire_jail_unref(jail
);
2621 int pakfire_jail_run_script(struct pakfire
* pakfire
,
2622 const char* script
, const size_t length
, const char* argv
[], int flags
) {
2623 struct pakfire_jail
* jail
= NULL
;
2626 // Create a new jail
2627 r
= pakfire_jail_create(&jail
, pakfire
);
2631 // Execute the command
2632 r
= pakfire_jail_exec_script(jail
, script
, length
, argv
, NULL
, NULL
, NULL
);
2636 pakfire_jail_unref(jail
);
2641 int pakfire_jail_shell(struct pakfire_jail
* jail
) {
2644 const char* argv
[] = {
2645 "/bin/bash", "--login", NULL
,
2648 // Execute /bin/bash
2649 r
= pakfire_jail_exec_interactive(jail
, argv
, 0);
2655 // Ignore any return codes from the shell
2659 static int pakfire_jail_run_if_possible(struct pakfire
* pakfire
, const char** argv
) {
2660 char path
[PATH_MAX
];
2663 r
= pakfire_path(pakfire
, path
, "%s", *argv
);
2667 // Check if the file is executable
2668 r
= access(path
, X_OK
);
2670 DEBUG(pakfire
, "%s is not executable. Skipping...\n", *argv
);
2674 return pakfire_jail_run(pakfire
, argv
, 0, NULL
);
2677 int pakfire_jail_ldconfig(struct pakfire
* pakfire
) {
2678 const char* argv
[] = {
2683 return pakfire_jail_run_if_possible(pakfire
, argv
);
2686 int pakfire_jail_run_systemd_tmpfiles(struct pakfire
* pakfire
) {
2687 const char* argv
[] = {
2688 "/usr/bin/systemd-tmpfiles",
2693 return pakfire_jail_run_if_possible(pakfire
, argv
);