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
) {
247 INFO(pakfire
, "%s", line
);
251 ERROR(pakfire
, "%s", line
);
256 DEBUG(pakfire
, "%s", line
);
264 static const char* pakfire_jail_uuid(struct pakfire_jail
* jail
) {
266 uuid_unparse_lower(jail
->uuid
, jail
->__uuid
);
271 static int pakfire_jail_setup_interactive_env(struct pakfire_jail
* jail
) {
273 int r
= pakfire_jail_set_env(jail
, "PS1", "pakfire-jail \\w> ");
278 char* TERM
= secure_getenv("TERM");
280 r
= pakfire_jail_set_env(jail
, "TERM", TERM
);
286 char* LANG
= secure_getenv("LANG");
288 r
= pakfire_jail_set_env(jail
, "LANG", LANG
);
296 PAKFIRE_EXPORT
int pakfire_jail_create(struct pakfire_jail
** jail
, struct pakfire
* pakfire
) {
299 const char* arch
= pakfire_get_effective_arch(pakfire
);
301 // Allocate a new jail
302 struct pakfire_jail
* j
= calloc(1, sizeof(*j
));
307 j
->ctx
= pakfire_ctx(pakfire
);
310 j
->pakfire
= pakfire_ref(pakfire
);
312 // Initialize reference counter
315 // Generate a random UUID
316 uuid_generate_random(j
->uuid
);
318 DEBUG(j
->pakfire
, "Allocated new jail at %p\n", j
);
320 // Set the default logging callback
321 pakfire_jail_set_log_callback(j
, pakfire_jail_default_log_callback
, NULL
);
323 // Set default environment
324 for (const struct environ
* e
= ENV
; e
->key
; e
++) {
325 r
= pakfire_jail_set_env(j
, e
->key
, e
->val
);
330 // Enable all CPU features that CPU has to offer
331 if (!pakfire_arch_is_supported_by_host(arch
)) {
332 r
= pakfire_jail_set_env(j
, "QEMU_CPU", "max");
337 // Set container UUID
338 r
= pakfire_jail_set_env(j
, "container_uuid", pakfire_jail_uuid(j
));
342 // Disable systemctl to talk to systemd
343 if (!pakfire_on_root(j
->pakfire
)) {
344 r
= pakfire_jail_set_env(j
, "SYSTEMD_OFFLINE", "1");
354 pakfire_jail_free(j
);
359 PAKFIRE_EXPORT
struct pakfire_jail
* pakfire_jail_ref(struct pakfire_jail
* jail
) {
365 PAKFIRE_EXPORT
struct pakfire_jail
* pakfire_jail_unref(struct pakfire_jail
* jail
) {
366 if (--jail
->nrefs
> 0)
369 pakfire_jail_free(jail
);
375 PAKFIRE_EXPORT
void pakfire_jail_set_log_callback(struct pakfire_jail
* jail
,
376 pakfire_jail_log_callback callback
, void* data
) {
377 jail
->callbacks
.log
= callback
;
378 jail
->callbacks
.log_data
= data
;
383 PAKFIRE_EXPORT
int pakfire_jail_nice(struct pakfire_jail
* jail
, int nice
) {
384 // Check if nice level is in range
385 if (nice
< -19 || nice
> 20) {
396 int pakfire_jail_set_cgroup(struct pakfire_jail
* jail
, struct pakfire_cgroup
* cgroup
) {
397 // Free any previous cgroup
399 pakfire_cgroup_unref(jail
->cgroup
);
403 // Set any new cgroup
405 DEBUG(jail
->pakfire
, "Setting cgroup %p\n", cgroup
);
407 jail
->cgroup
= pakfire_cgroup_ref(cgroup
);
416 // Returns the length of the environment
417 static unsigned int pakfire_jail_env_length(struct pakfire_jail
* jail
) {
420 // Count everything in the environment
421 for (char** e
= jail
->env
; *e
; e
++)
427 // Finds an existing environment variable and returns its index or -1 if not found
428 static int pakfire_jail_find_env(struct pakfire_jail
* jail
, const char* key
) {
434 const size_t length
= strlen(key
);
436 for (unsigned int i
= 0; jail
->env
[i
]; i
++) {
437 if ((pakfire_string_startswith(jail
->env
[i
], key
)
438 && *(jail
->env
[i
] + length
) == '=')) {
447 // Returns the value of an environment variable or NULL
448 PAKFIRE_EXPORT
const char* pakfire_jail_get_env(struct pakfire_jail
* jail
,
450 int i
= pakfire_jail_find_env(jail
, key
);
454 return jail
->env
[i
] + strlen(key
) + 1;
457 // Sets an environment variable
458 PAKFIRE_EXPORT
int pakfire_jail_set_env(struct pakfire_jail
* jail
,
459 const char* key
, const char* value
) {
460 // Find the index where to write this value to
461 int i
= pakfire_jail_find_env(jail
, key
);
463 i
= pakfire_jail_env_length(jail
);
465 // Return -ENOSPC when the environment is full
466 if (i
>= ENVIRON_SIZE
) {
471 // Free any previous value
475 // Format and set environment variable
476 asprintf(&jail
->env
[i
], "%s=%s", key
, value
);
478 DEBUG(jail
->pakfire
, "Set environment variable: %s\n", jail
->env
[i
]);
483 // Imports an environment
484 PAKFIRE_EXPORT
int pakfire_jail_import_env(struct pakfire_jail
* jail
, const char* env
[]) {
492 // Copy environment variables
493 for (unsigned int i
= 0; env
[i
]; i
++) {
494 r
= pakfire_string_partition(env
[i
], "=", &key
, &val
);
499 r
= pakfire_jail_set_env(jail
, key
, val
);
516 PAKFIRE_EXPORT
int pakfire_jail_set_timeout(
517 struct pakfire_jail
* jail
, unsigned int timeout
) {
519 jail
->timeout
.it_value
.tv_sec
= timeout
;
522 DEBUG(jail
->pakfire
, "Timeout set to %u second(s)\n", timeout
);
524 DEBUG(jail
->pakfire
, "Timeout disabled\n");
529 static int pakfire_jail_create_timer(struct pakfire_jail
* jail
) {
532 // Nothing to do if no timeout has been set
533 if (!jail
->timeout
.it_value
.tv_sec
)
536 // Create a new timer
537 const int fd
= timerfd_create(CLOCK_MONOTONIC
, 0);
539 ERROR(jail
->pakfire
, "Could not create timer: %m\n");
544 r
= timerfd_settime(fd
, 0, &jail
->timeout
, NULL
);
546 ERROR(jail
->pakfire
, "Could not arm timer: %m\n");
560 This function replaces any logging in the child process.
562 All log messages will be sent to the parent process through their respective pipes.
564 static void pakfire_jail_log_redirect(void* data
, int priority
, const char* file
,
565 int line
, const char* fn
, const char* format
, va_list args
) {
566 struct pakfire_jail_pipes
* pipes
= (struct pakfire_jail_pipes
*)data
;
571 fd
= pipes
->log_INFO
[1];
575 fd
= pipes
->log_ERROR
[1];
580 fd
= pipes
->log_DEBUG
[1];
582 #endif /* ENABLE_DEBUG */
584 // Ignore any messages of an unknown priority
589 // Send the log message
591 vdprintf(fd
, format
, args
);
594 static int pakfire_jail_log_buffer_is_full(const struct pakfire_log_buffer
* buffer
) {
595 return (sizeof(buffer
->data
) == buffer
->used
);
598 static int pakfire_jail_fill_buffer(struct pakfire_jail
* jail
, int fd
, struct pakfire_log_buffer
* buffer
) {
601 // Skip this if there is not space left in the buffer
602 if (buffer
->used
>= sizeof(buffer
->data
))
606 r
= read(fd
, buffer
->data
+ buffer
->used
, sizeof(buffer
->data
) - buffer
->used
);
621 // XXX What to do here?
631 static int pakfire_jail_drain_buffer_with_callback(struct pakfire_jail
* jail
,
632 struct pakfire_log_buffer
* buffer
, int priority
, pakfire_jail_communicate_out callback
, void* data
) {
633 const char* eol
= NULL
;
636 while (buffer
->used
) {
637 // Search for the end of the first line
638 eol
= memchr(buffer
->data
, '\n', buffer
->used
);
642 // If the buffer is full, we send the entire content to make space.
643 if (pakfire_jail_log_buffer_is_full(buffer
)) {
644 CTX_DEBUG(jail
->ctx
, "Buffer is full. Sending all content\n");
646 eol
= buffer
->data
+ buffer
->used
- 1;
648 // Otherwise we might have only read parts of the output...
654 // Find the length of the string
655 const size_t length
= eol
- buffer
->data
+ 1;
658 r
= callback(jail
->pakfire
, data
, priority
, buffer
->data
, length
);
660 CTX_ERROR(jail
->ctx
, "The logging callback returned an error: %d\n", r
);
664 // Remove line from buffer
665 memmove(buffer
->data
, buffer
->data
+ length
, buffer
->used
- length
);
666 buffer
->used
-= length
;
672 static int pakfire_jail_drain_buffer(struct pakfire_jail
* jail
, int fd
, struct pakfire_log_buffer
* buffer
) {
675 // Nothing to do if the buffer is empty
680 r
= write(fd
, buffer
->data
, buffer
->used
);
695 memmove(buffer
->data
, buffer
->data
+ r
, buffer
->used
- r
);
704 This function reads as much data as it can from the file descriptor.
705 If it finds a whole line in it, it will send it to the logger and repeat the process.
706 If not newline character is found, it will try to read more data until it finds one.
708 static int pakfire_jail_handle_log(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
,
709 int priority
, int fd
, struct pakfire_log_buffer
* buffer
,
710 pakfire_jail_communicate_out callback
, void* data
) {
713 // Fill up buffer from fd
714 r
= pakfire_jail_fill_buffer(jail
, fd
, buffer
);
719 r
= pakfire_jail_drain_buffer_with_callback(jail
, buffer
, priority
, callback
, data
);
727 static int pakfire_jail_stream_stdin(struct pakfire_jail
* jail
,
728 struct pakfire_jail_exec
* ctx
, const int fd
) {
731 // Nothing to do if there is no stdin callback set
732 if (!ctx
->communicate
.in
) {
733 DEBUG(jail
->pakfire
, "Callback for standard input is not set\n");
737 // Skip if the writing pipe has already been closed
738 if (ctx
->pipes
.stdin
[1] < 0)
741 DEBUG(jail
->pakfire
, "Streaming standard input...\n");
743 // Calling the callback
744 r
= ctx
->communicate
.in(jail
->pakfire
, ctx
->communicate
.data
, fd
);
746 DEBUG(jail
->pakfire
, "Standard input callback finished: %d\n", r
);
748 // The callback signaled that it has written everything
750 DEBUG(jail
->pakfire
, "Closing standard input pipe\n");
752 // Close the file-descriptor
755 // Reset the file-descriptor so it won't be closed again later
756 ctx
->pipes
.stdin
[1] = -1;
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_log(struct pakfire
* pakfire
, void* data
, int priority
,
884 const char* line
, const size_t length
) {
885 // Pass everything to the parent logger
886 pakfire_log_condition(pakfire
, priority
, 0, "%.*s", (int)length
, line
);
891 static int pakfire_jail_epoll_add_fd(struct pakfire_jail
* jail
, int epollfd
, int fd
, int events
) {
892 struct epoll_event event
= {
893 .events
= events
|EPOLLHUP
,
901 int flags
= fcntl(fd
, F_GETFL
, 0);
903 // Set modified flags
904 r
= fcntl(fd
, F_SETFL
, flags
|O_NONBLOCK
);
906 CTX_ERROR(jail
->ctx
, "Could not set file descriptor %d into non-blocking mode: %s\n",
907 fd
, strerror(errno
));
911 // Add the file descriptor to the loop
912 r
= epoll_ctl(epollfd
, EPOLL_CTL_ADD
, fd
, &event
);
914 ERROR(jail
->pakfire
, "Could not add file descriptor %d to epoll(): %s\n",
915 fd
, strerror(errno
));
924 static int pakfire_jail_enable_raw_mode(struct pakfire_jail
* jail
,
925 struct pakfire_jail_pty_stdio
* stdio
) {
926 struct termios raw_attrs
;
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
) {
978 r
= fcntl(stdio
->fd
, F_SETFL
, stdio
->fdflags
);
980 CTX_ERROR(jail
->ctx
, "Could not set flags for file descriptor %d: %s\n",
981 stdio
->fd
, strerror(errno
));
985 // Restore the attributes
986 r
= tcsetattr(stdio
->fd
, TCSANOW
, &stdio
->attrs
);
988 CTX_ERROR(jail
->ctx
, "Could not restore terminal attributes for %d, ignoring: %s\n",
989 stdio
->fd
, strerror(errno
));
996 static int pakfire_jail_setup_pty_forwarding(struct pakfire_jail
* jail
,
997 struct pakfire_jail_exec
* ctx
, const int epollfd
, const int fd
) {
1001 CTX_DEBUG(jail
->ctx
, "Setting up PTY forwarding on fd %d\n", fd
);
1003 // Store the file descriptor
1004 ctx
->pty
.master
.fd
= fd
;
1006 // Configure stdin/stdout
1007 ctx
->pty
.stdin
.fd
= STDIN_FILENO
;
1008 ctx
->pty
.stdout
.fd
= STDOUT_FILENO
;
1011 r
= ioctl(ctx
->pty
.stdout
.fd
, TIOCGWINSZ
, &size
);
1013 CTX_ERROR(jail
->ctx
, "Failed to determine terminal dimensions: %s\n", strerror(errno
));
1018 r
= ioctl(ctx
->pty
.master
.fd
, TIOCSWINSZ
, &size
);
1020 CTX_ERROR(jail
->ctx
, "Failed setting dimensions: %s\n", strerror(errno
));
1024 // Enable RAW mode on standard input
1025 r
= pakfire_jail_enable_raw_mode(jail
, &ctx
->pty
.stdin
);
1029 // Enable RAW mode on standard output
1030 r
= pakfire_jail_enable_raw_mode(jail
, &ctx
->pty
.stdout
);
1034 // Add the master to the event loop
1035 r
= pakfire_jail_epoll_add_fd(jail
, epollfd
, ctx
->pty
.master
.fd
, EPOLLIN
|EPOLLOUT
|EPOLLET
);
1039 // Add standard input to the event loop
1040 r
= pakfire_jail_epoll_add_fd(jail
, epollfd
, ctx
->pty
.stdin
.fd
, EPOLLIN
|EPOLLET
);
1044 // Add standard output to the event loop
1045 r
= pakfire_jail_epoll_add_fd(jail
, epollfd
, ctx
->pty
.stdout
.fd
, EPOLLOUT
|EPOLLET
);
1052 static int pakfire_jail_forward_pty(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1055 // Read from standard input
1056 if (ctx
->pty
.stdin
.flags
& PAKFIRE_JAIL_PTY_READY_TO_READ
) {
1057 r
= pakfire_jail_fill_buffer(jail
, ctx
->pty
.stdin
.fd
, &ctx
->pty
.stdin
.buffer
);
1059 CTX_ERROR(jail
->ctx
, "Failed reading from standard input: %s\n", strerror(-r
));
1063 // We are done reading for now
1064 ctx
->pty
.stdin
.flags
&= ~PAKFIRE_JAIL_PTY_READY_TO_READ
;
1066 // But we may have data to write
1067 if (ctx
->pty
.stdin
.buffer
.used
)
1068 ctx
->pty
.master
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1071 // Write to the master
1072 if (ctx
->pty
.master
.flags
& PAKFIRE_JAIL_PTY_READY_TO_WRITE
) {
1073 r
= pakfire_jail_drain_buffer(jail
, ctx
->pty
.master
.fd
, &ctx
->pty
.stdin
.buffer
);
1075 CTX_ERROR(jail
->ctx
, "Failed writing to the PTY: %s\n", strerror(-r
));
1079 // We are done writing for now
1080 ctx
->pty
.master
.flags
&= ~PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1083 // Read from the master
1084 if (ctx
->pty
.master
.flags
& PAKFIRE_JAIL_PTY_READY_TO_READ
) {
1085 r
= pakfire_jail_fill_buffer(jail
, ctx
->pty
.master
.fd
, &ctx
->pty
.stdout
.buffer
);
1087 CTX_ERROR(jail
->ctx
, "Failed reading from the PTY: %s\n", strerror(-r
));
1091 // We are done reading for now
1092 ctx
->pty
.master
.flags
&= ~PAKFIRE_JAIL_PTY_READY_TO_READ
;
1094 // But we may have data to write
1095 if (ctx
->pty
.stdout
.buffer
.used
)
1096 ctx
->pty
.stdout
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1099 // Write to standard output
1100 if (ctx
->pty
.stdout
.flags
& PAKFIRE_JAIL_PTY_READY_TO_WRITE
) {
1101 r
= pakfire_jail_drain_buffer(jail
, ctx
->pty
.stdout
.fd
, &ctx
->pty
.stdout
.buffer
);
1103 CTX_ERROR(jail
->ctx
, "Failed writing to standard output: %s\n", strerror(-r
));
1107 // We are done writing for now
1108 ctx
->pty
.stdout
.flags
&= ~PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1114 static int pakfire_jail_wait(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1116 struct epoll_event events
[EPOLL_MAX_EVENTS
];
1120 // Fetch file descriptors from context
1121 const int pidfd
= ctx
->pidfd
;
1123 // Fetch the UNIX domain socket
1124 const int socket_recv
= pakfire_jail_get_pipe_to_read(jail
, &ctx
->socket
);
1127 const int timerfd
= pakfire_jail_create_timer(jail
);
1130 const int log_INFO
= pakfire_jail_get_pipe_to_read(jail
, &ctx
->pipes
.log_INFO
);
1131 const int log_ERROR
= pakfire_jail_get_pipe_to_read(jail
, &ctx
->pipes
.log_ERROR
);
1133 const int log_DEBUG
= pakfire_jail_get_pipe_to_read(jail
, &ctx
->pipes
.log_DEBUG
);
1134 #endif /* ENABLE_DEBUG */
1136 // Make a list of all file descriptors we are interested in
1137 const struct pakfire_wait_fds
{
1142 { timerfd
, EPOLLIN
},
1145 { ctx
->pidfd
, EPOLLIN
},
1148 { log_INFO
, EPOLLIN
},
1149 { log_ERROR
, EPOLLIN
},
1151 { log_DEBUG
, EPOLLIN
},
1152 #endif /* ENABLE_DEBUG */
1154 // UNIX Domain Socket
1155 { socket_recv
, EPOLLIN
},
1162 epollfd
= epoll_create1(0);
1164 ERROR(jail
->pakfire
, "Could not initialize epoll(): %m\n");
1169 // Turn file descriptors into non-blocking mode and add them to epoll()
1170 for (const struct pakfire_wait_fds
* fd
= fds
; fd
->events
; fd
++) {
1171 // Skip fds which were not initialized
1175 // Add the FD to the event loop
1176 r
= pakfire_jail_epoll_add_fd(jail
, epollfd
, fd
->fd
, fd
->events
);
1183 // Loop for as long as the process is alive
1185 int num
= epoll_wait(epollfd
, events
, EPOLL_MAX_EVENTS
, -1);
1187 // Ignore if epoll_wait() has been interrupted
1191 ERROR(jail
->pakfire
, "epoll_wait() failed: %m\n");
1197 for (int i
= 0; i
< num
; i
++) {
1198 int e
= events
[i
].events
;
1199 int fd
= events
[i
].data
.fd
;
1201 // Handle PTY forwarding events
1202 if (ctx
->pty
.master
.fd
== fd
) {
1203 if (e
& (EPOLLIN
|EPOLLHUP
))
1204 ctx
->pty
.master
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_READ
;
1206 if (e
& (EPOLLOUT
|EPOLLHUP
))
1207 ctx
->pty
.master
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1210 r
= pakfire_jail_forward_pty(jail
, ctx
);
1212 CTX_ERROR(jail
->ctx
, "Failed forwarding the PTY: %s\n", strerror(-r
));
1216 // Handle standard input
1217 } else if (ctx
->pty
.stdin
.fd
== fd
) {
1218 if (e
& (EPOLLIN
|EPOLLHUP
))
1219 ctx
->pty
.stdin
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_READ
;
1222 r
= pakfire_jail_forward_pty(jail
, ctx
);
1224 CTX_ERROR(jail
->ctx
, "Failed forwarding the PTY: %s\n", strerror(-r
));
1228 // Handle standard output
1229 } else if (ctx
->pty
.stdout
.fd
== fd
) {
1230 if (e
& (EPOLLOUT
|EPOLLHUP
))
1231 ctx
->pty
.stdout
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1234 r
= pakfire_jail_forward_pty(jail
, ctx
);
1236 CTX_ERROR(jail
->ctx
, "Failed forwarding the PTY: %s\n", strerror(-r
));
1240 // Handle any changes to the PIDFD
1241 } else if (pidfd
== fd
) {
1243 // Call waidid() and store the result
1244 r
= waitid(P_PIDFD
, ctx
->pidfd
, &ctx
->status
, WEXITED
);
1246 ERROR(jail
->pakfire
, "waitid() failed: %m\n");
1250 // Mark that we have ended so that we will process the remaining
1251 // events from epoll() now, but won't restart the outer loop.
1255 // Handle timer events
1256 } else if (timerfd
== fd
) {
1258 DEBUG(jail
->pakfire
, "Timer event received\n");
1261 r
= read(timerfd
, garbage
, sizeof(garbage
));
1263 ERROR(jail
->pakfire
, "Could not disarm timer: %m\n");
1268 // Terminate the process if it hasn't already ended
1270 DEBUG(jail
->pakfire
, "Terminating process...\n");
1272 // Send SIGTERM to the process
1273 r
= pidfd_send_signal(pidfd
, SIGKILL
, NULL
, 0);
1275 ERROR(jail
->pakfire
, "Could not kill process: %m\n");
1281 // Handle socket messages
1282 } else if (socket_recv
== fd
) {
1284 // Receive the passed FD
1285 r
= pakfire_jail_recv_fd(jail
, socket_recv
, &fd
);
1289 // Setup PTY forwarding
1290 if (ctx
->pty
.master
.fd
< 0) {
1291 r
= pakfire_jail_setup_pty_forwarding(jail
, ctx
, epollfd
, fd
);
1293 CTX_ERROR(jail
->ctx
, "Failed setting up PTY forwarding: %s\n", strerror(-r
));
1299 // Handle log INFO messages
1300 } else if (log_INFO
== fd
) {
1302 r
= pakfire_jail_handle_log(jail
, ctx
, LOG_INFO
, fd
,
1303 &ctx
->buffers
.log_INFO
, pakfire_jail_log
, NULL
);
1308 // Handle log ERROR messages
1309 } else if (log_ERROR
== fd
) {
1311 r
= pakfire_jail_handle_log(jail
, ctx
, LOG_ERR
, fd
,
1312 &ctx
->buffers
.log_ERROR
, pakfire_jail_log
, NULL
);
1318 // Handle log DEBUG messages
1319 } else if (log_DEBUG
== fd
) {
1321 r
= pakfire_jail_handle_log(jail
, ctx
, LOG_DEBUG
, fd
,
1322 &ctx
->buffers
.log_DEBUG
, pakfire_jail_log
, NULL
);
1326 #endif /* ENABLE_DEBUG */
1328 // Log a message for anything else
1330 DEBUG(jail
->pakfire
, "Received invalid file descriptor %d\n", fd
);
1334 // Check if any file descriptors have been closed
1336 // Remove the file descriptor
1337 r
= epoll_ctl(epollfd
, EPOLL_CTL_DEL
, fd
, NULL
);
1339 ERROR(jail
->pakfire
, "Could not remove closed file-descriptor %d: %m\n", fd
);
1352 // Restore any changed terminal attributes
1353 if (ctx
->pty
.stdin
.fd
>= 0)
1354 pakfire_jail_restore_attrs(jail
, &ctx
->pty
.stdin
);
1355 if (ctx
->pty
.stdout
.fd
>= 0)
1356 pakfire_jail_restore_attrs(jail
, &ctx
->pty
.stdout
);
1361 int pakfire_jail_capture_stdout(struct pakfire
* pakfire
, void* data
,
1362 int priority
, const char* line
, size_t length
) {
1363 char** output
= (char**)data
;
1366 // Append everything from stdout to a buffer
1367 if (output
&& priority
== LOG_INFO
) {
1368 r
= asprintf(output
, "%s%s", (output
&& *output
) ? *output
: "", line
);
1374 // Send everything else to the default logger
1375 return pakfire_jail_default_log_callback(pakfire
, NULL
, priority
, line
, length
);
1380 // Logs all capabilities of the current process
1381 static int pakfire_jail_show_capabilities(struct pakfire_jail
* jail
) {
1384 cap_flag_value_t value_e
;
1385 cap_flag_value_t value_i
;
1386 cap_flag_value_t value_p
;
1390 pid_t pid
= getpid();
1392 // Fetch all capabilities
1393 caps
= cap_get_proc();
1395 ERROR(jail
->pakfire
, "Could not fetch capabilities: %m\n");
1400 DEBUG(jail
->pakfire
, "Capabilities of PID %d:\n", pid
);
1402 // Iterate over all capabilities
1403 for (unsigned int cap
= 0; cap_valid(cap
); cap
++) {
1404 name
= cap_to_name(cap
);
1406 // Fetch effective value
1407 r
= cap_get_flag(caps
, cap
, CAP_EFFECTIVE
, &value_e
);
1411 // Fetch inheritable value
1412 r
= cap_get_flag(caps
, cap
, CAP_INHERITABLE
, &value_i
);
1416 // Fetch permitted value
1417 r
= cap_get_flag(caps
, cap
, CAP_PERMITTED
, &value_p
);
1421 DEBUG(jail
->pakfire
,
1422 " %-24s : %c%c%c\n",
1424 (value_e
== CAP_SET
) ? 'e' : '-',
1425 (value_i
== CAP_SET
) ? 'i' : '-',
1426 (value_p
== CAP_SET
) ? 'p' : '-'
1446 static int pakfire_jail_set_capabilities(struct pakfire_jail
* jail
) {
1451 // Fetch capabilities
1452 caps
= cap_get_proc();
1454 ERROR(jail
->pakfire
, "Could not read capabilities: %m\n");
1459 // Walk through all capabilities
1460 for (cap_value_t cap
= 0; cap_valid(cap
); cap
++) {
1461 cap_value_t _caps
[] = { cap
};
1463 // Fetch the name of the capability
1464 name
= cap_to_name(cap
);
1466 r
= cap_set_flag(caps
, CAP_EFFECTIVE
, 1, _caps
, CAP_SET
);
1468 ERROR(jail
->pakfire
, "Could not set %s: %m\n", name
);
1472 r
= cap_set_flag(caps
, CAP_INHERITABLE
, 1, _caps
, CAP_SET
);
1474 ERROR(jail
->pakfire
, "Could not set %s: %m\n", name
);
1478 r
= cap_set_flag(caps
, CAP_PERMITTED
, 1, _caps
, CAP_SET
);
1480 ERROR(jail
->pakfire
, "Could not set %s: %m\n", name
);
1489 // Restore all capabilities
1490 r
= cap_set_proc(caps
);
1492 ERROR(jail
->pakfire
, "Restoring capabilities failed: %m\n");
1496 // Add all capabilities to the ambient set
1497 for (unsigned int cap
= 0; cap_valid(cap
); cap
++) {
1498 name
= cap_to_name(cap
);
1500 // Raise the capability
1501 r
= prctl(PR_CAP_AMBIENT
, PR_CAP_AMBIENT_RAISE
, cap
, 0, 0);
1503 ERROR(jail
->pakfire
, "Could not set ambient capability %s: %m\n", name
);
1526 static int pakfire_jail_limit_syscalls(struct pakfire_jail
* jail
) {
1527 const int syscalls
[] = {
1528 // The kernel's keyring isn't namespaced
1531 SCMP_SYS(request_key
),
1533 // Disable userfaultfd
1534 SCMP_SYS(userfaultfd
),
1536 // Disable perf which could leak a lot of information about the host
1537 SCMP_SYS(perf_event_open
),
1543 DEBUG(jail
->pakfire
, "Applying syscall filter...\n");
1545 // Setup a syscall filter which allows everything by default
1546 scmp_filter_ctx ctx
= seccomp_init(SCMP_ACT_ALLOW
);
1548 ERROR(jail
->pakfire
, "Could not setup seccomp filter: %m\n");
1553 for (const int* syscall
= syscalls
; *syscall
; syscall
++) {
1554 r
= seccomp_rule_add(ctx
, SCMP_ACT_ERRNO(EPERM
), *syscall
, 0);
1556 ERROR(jail
->pakfire
, "Could not configure syscall %d: %m\n", *syscall
);
1561 // Load syscall filter into the kernel
1562 r
= seccomp_load(ctx
);
1564 ERROR(jail
->pakfire
, "Could not load syscall filter into the kernel: %m\n");
1570 seccomp_release(ctx
);
1577 PAKFIRE_EXPORT
int pakfire_jail_bind(struct pakfire_jail
* jail
,
1578 const char* source
, const char* target
, int flags
) {
1579 struct pakfire_jail_mountpoint
* mp
= NULL
;
1582 // Check if there is any space left
1583 if (jail
->num_mountpoints
>= MAX_MOUNTPOINTS
) {
1588 // Check for valid inputs
1589 if (!source
|| !target
) {
1594 // Select the next free slot
1595 mp
= &jail
->mountpoints
[jail
->num_mountpoints
];
1598 r
= pakfire_string_set(mp
->source
, source
);
1600 ERROR(jail
->pakfire
, "Could not copy source: %m\n");
1605 r
= pakfire_string_set(mp
->target
, target
);
1607 ERROR(jail
->pakfire
, "Could not copy target: %m\n");
1614 // Increment counter
1615 jail
->num_mountpoints
++;
1620 static int pakfire_jail_mount_networking(struct pakfire_jail
* jail
) {
1623 const char* paths
[] = {
1629 // Bind-mount all paths read-only
1630 for (const char** path
= paths
; *path
; path
++) {
1631 r
= pakfire_bind(jail
->pakfire
, *path
, NULL
, MS_RDONLY
);
1634 // Ignore if we don't have permission
1649 Mounts everything that we require in the new namespace
1651 static int pakfire_jail_mount(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1652 struct pakfire_jail_mountpoint
* mp
= NULL
;
1656 // Enable loop devices
1657 if (pakfire_jail_exec_has_flag(ctx
, PAKFIRE_JAIL_HAS_LOOP_DEVICES
))
1658 flags
|= PAKFIRE_MOUNT_LOOP_DEVICES
;
1660 // Mount all default stuff
1661 r
= pakfire_mount_all(jail
->pakfire
, PAKFIRE_MNTNS_OUTER
, flags
);
1666 r
= pakfire_populate_dev(jail
->pakfire
, flags
);
1670 // Mount the interpreter (if needed)
1671 r
= pakfire_mount_interpreter(jail
->pakfire
);
1675 // Mount networking stuff
1676 if (pakfire_jail_exec_has_flag(ctx
, PAKFIRE_JAIL_HAS_NETWORKING
)) {
1677 r
= pakfire_jail_mount_networking(jail
);
1682 // Mount all custom stuff
1683 for (unsigned int i
= 0; i
< jail
->num_mountpoints
; i
++) {
1685 mp
= &jail
->mountpoints
[i
];
1688 r
= pakfire_bind(jail
->pakfire
, mp
->source
, mp
->target
, mp
->flags
);
1698 static int pakfire_jail_setup_loopback(struct pakfire_jail
* jail
) {
1699 struct nl_sock
* nl
= NULL
;
1700 struct nl_cache
* cache
= NULL
;
1701 struct rtnl_link
* link
= NULL
;
1702 struct rtnl_link
* change
= NULL
;
1705 DEBUG(jail
->pakfire
, "Setting up loopback...\n");
1707 // Allocate a netlink socket
1708 nl
= nl_socket_alloc();
1710 ERROR(jail
->pakfire
, "Could not allocate a netlink socket: %m\n");
1715 // Connect the socket
1716 r
= nl_connect(nl
, NETLINK_ROUTE
);
1718 ERROR(jail
->pakfire
, "Could not connect netlink socket: %s\n", nl_geterror(r
));
1722 // Allocate the netlink cache
1723 r
= rtnl_link_alloc_cache(nl
, AF_UNSPEC
, &cache
);
1725 ERROR(jail
->pakfire
, "Unable to allocate netlink cache: %s\n", nl_geterror(r
));
1729 // Fetch loopback interface
1730 link
= rtnl_link_get_by_name(cache
, "lo");
1732 ERROR(jail
->pakfire
, "Could not find lo interface. Ignoring.\n");
1737 // Allocate a new link
1738 change
= rtnl_link_alloc();
1740 ERROR(jail
->pakfire
, "Could not allocate change link\n");
1745 // Set the link to UP
1746 rtnl_link_set_flags(change
, IFF_UP
);
1748 // Apply any changes
1749 r
= rtnl_link_change(nl
, link
, change
, 0);
1751 ERROR(jail
->pakfire
, "Unable to activate loopback: %s\n", nl_geterror(r
));
1767 static int pakfire_jail_setup_uid_mapping(struct pakfire_jail
* jail
, pid_t pid
) {
1768 char path
[PATH_MAX
];
1771 // Skip mapping anything when running on /
1772 if (pakfire_on_root(jail
->pakfire
))
1776 r
= pakfire_string_format(path
, "/proc/%d/uid_map", pid
);
1781 const uid_t uid
= pakfire_uid(jail
->pakfire
);
1784 const struct pakfire_subid
* subuid
= pakfire_subuid(jail
->pakfire
);
1788 /* When running as root, we will map the entire range.
1790 When running as a non-privileged user, we will map the root user inside the jail
1791 to the user's UID outside of the jail, and we will map the rest starting from one.
1796 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0,
1797 "0 %lu %lu\n", subuid
->id
, subuid
->length
);
1799 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0,
1800 "0 %lu 1\n1 %lu %lu\n", uid
, subuid
->id
, subuid
->length
);
1804 ERROR(jail
->pakfire
, "Could not map UIDs: %m\n");
1811 static int pakfire_jail_setup_gid_mapping(struct pakfire_jail
* jail
, pid_t pid
) {
1812 char path
[PATH_MAX
];
1815 // Skip mapping anything when running on /
1816 if (pakfire_on_root(jail
->pakfire
))
1820 const gid_t gid
= pakfire_gid(jail
->pakfire
);
1823 const struct pakfire_subid
* subgid
= pakfire_subgid(jail
->pakfire
);
1828 r
= pakfire_string_format(path
, "/proc/%d/gid_map", pid
);
1834 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0,
1835 "0 %lu %lu\n", subgid
->id
, subgid
->length
);
1837 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0,
1838 "0 %lu 1\n1 %lu %lu\n", gid
, subgid
->id
, subgid
->length
);
1842 ERROR(jail
->pakfire
, "Could not map GIDs: %m\n");
1849 static int pakfire_jail_setgroups(struct pakfire_jail
* jail
, pid_t pid
) {
1850 char path
[PATH_MAX
];
1854 r
= pakfire_string_format(path
, "/proc/%d/setgroups", pid
);
1858 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0, "deny\n");
1860 CTX_ERROR(jail
->ctx
, "Could not set setgroups to deny: %s\n", strerror(errno
));
1867 static int pakfire_jail_send_signal(struct pakfire_jail
* jail
, int fd
) {
1868 const uint64_t val
= 1;
1871 DEBUG(jail
->pakfire
, "Sending signal...\n");
1873 // Write to the file descriptor
1874 r
= eventfd_write(fd
, val
);
1876 ERROR(jail
->pakfire
, "Could not send signal: %s\n", strerror(errno
));
1880 // Close the file descriptor
1886 static int pakfire_jail_wait_for_signal(struct pakfire_jail
* jail
, int fd
) {
1890 DEBUG(jail
->pakfire
, "Waiting for signal...\n");
1892 r
= eventfd_read(fd
, &val
);
1894 ERROR(jail
->pakfire
, "Error waiting for signal: %s\n", strerror(errno
));
1898 // Close the file descriptor
1905 Performs the initialisation that needs to happen in the parent part
1907 static int pakfire_jail_parent(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1910 // Setup UID mapping
1911 r
= pakfire_jail_setup_uid_mapping(jail
, ctx
->pid
);
1915 // Write "deny" to /proc/PID/setgroups
1916 r
= pakfire_jail_setgroups(jail
, ctx
->pid
);
1920 // Setup GID mapping
1921 r
= pakfire_jail_setup_gid_mapping(jail
, ctx
->pid
);
1925 // Parent has finished initialisation
1926 DEBUG(jail
->pakfire
, "Parent has finished initialization\n");
1928 // Send signal to client
1929 r
= pakfire_jail_send_signal(jail
, ctx
->completed_fd
);
1936 static int pakfire_jail_switch_root(struct pakfire_jail
* jail
, const char* root
) {
1939 // Change to the new root
1942 ERROR(jail
->pakfire
, "chdir(%s) failed: %m\n", root
);
1947 r
= pivot_root(".", ".");
1949 ERROR(jail
->pakfire
, "Failed changing into the new root directory %s: %m\n", root
);
1953 // Umount the old root
1954 r
= umount2(".", MNT_DETACH
);
1956 ERROR(jail
->pakfire
, "Could not umount the old root filesystem: %m\n");
1963 static int pakfire_jail_open_pty(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1966 // Allocate a new PTY
1967 ctx
->pty
.master
.fd
= posix_openpt(O_RDWR
|O_NONBLOCK
|O_NOCTTY
|O_CLOEXEC
);
1968 if (ctx
->pty
.master
.fd
< 0)
1972 r
= ptsname_r(ctx
->pty
.master
.fd
, ctx
->pty
.console
, sizeof(ctx
->pty
.console
));
1976 CTX_DEBUG(jail
->ctx
, "Allocated console at %s (%d)\n", ctx
->pty
.console
, ctx
->pty
.master
.fd
);
1978 // Unlock the master device
1979 r
= unlockpt(ctx
->pty
.master
.fd
);
1981 CTX_ERROR(jail
->ctx
, "Could not unlock the PTY: %s\n", strerror(errno
));
1986 r
= pakfire_symlink(jail
->ctx
, ctx
->pty
.console
, "/dev/console");
1993 static int pakfire_jail_setup_terminal(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1997 // Open a new terminal
1998 fd
= open("/dev/console", O_RDWR
|O_NOCTTY
);
2000 CTX_ERROR(jail
->ctx
, "Failed to open a new terminal: %s\n", strerror(errno
));
2004 CTX_DEBUG(jail
->ctx
, "Opened a new terminal %d\n", fd
);
2006 // Connect the new terminal to standard input
2007 r
= dup2(fd
, STDIN_FILENO
);
2009 CTX_ERROR(jail
->ctx
, "Failed to open standard input: %s\n", strerror(errno
));
2013 // Connect the new terminal to standard output
2014 r
= dup2(fd
, STDOUT_FILENO
);
2016 CTX_ERROR(jail
->ctx
, "Failed to open standard output: %s\n", strerror(errno
));
2020 // Connect the new terminal to standard error
2021 r
= dup2(fd
, STDERR_FILENO
);
2023 CTX_ERROR(jail
->ctx
, "Failed to open standard error: %s\n", strerror(errno
));
2030 static int pakfire_jail_child(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
,
2031 const char* argv
[]) {
2034 // Redirect any logging to our log pipe
2035 pakfire_ctx_set_log_callback(jail
->ctx
, pakfire_jail_log_redirect
, &ctx
->pipes
);
2038 pid_t pid
= getpid();
2040 DEBUG(jail
->pakfire
, "Launched child process in jail with PID %d\n", pid
);
2042 // Wait for the parent to finish initialization
2043 r
= pakfire_jail_wait_for_signal(jail
, ctx
->completed_fd
);
2048 r
= prctl(PR_SET_PDEATHSIG
, SIGKILL
, 0, 0, 0);
2050 ERROR(jail
->pakfire
, "Could not configure to die with parent: %m\n");
2054 // Make this process dumpable
2055 r
= prctl (PR_SET_DUMPABLE
, 1, 0, 0, 0);
2057 ERROR(jail
->pakfire
, "Could not make the process dumpable: %m\n");
2061 // Don't drop any capabilities on setuid()
2062 r
= prctl(PR_SET_KEEPCAPS
, 1);
2064 ERROR(jail
->pakfire
, "Could not set PR_SET_KEEPCAPS: %m\n");
2069 uid_t uid
= getuid();
2070 gid_t gid
= getgid();
2073 uid_t euid
= geteuid();
2074 gid_t egid
= getegid();
2076 DEBUG(jail
->pakfire
, " UID: %u (effective %u)\n", uid
, euid
);
2077 DEBUG(jail
->pakfire
, " GID: %u (effective %u)\n", gid
, egid
);
2079 // Log all mountpoints
2080 pakfire_mount_list(jail
->ctx
);
2082 // Fail if we are not PID 1
2084 CTX_ERROR(jail
->ctx
, "Child process is not PID 1\n");
2088 // Fail if we are not running as root
2089 if (uid
|| gid
|| euid
|| egid
) {
2090 ERROR(jail
->pakfire
, "Child process is not running as root\n");
2094 const int socket_send
= pakfire_jail_get_pipe_to_write(jail
, &ctx
->socket
);
2096 // Mount all default stuff
2097 r
= pakfire_mount_all(jail
->pakfire
, PAKFIRE_MNTNS_INNER
, 0);
2101 const char* root
= pakfire_get_path(jail
->pakfire
);
2102 const char* arch
= pakfire_get_effective_arch(jail
->pakfire
);
2104 // Change mount propagation to slave to receive anything from the parent namespace
2105 r
= pakfire_mount_change_propagation(jail
->ctx
, "/", MS_SLAVE
);
2109 // Make root a mountpoint in the new mount namespace
2110 r
= pakfire_mount_make_mounpoint(jail
->pakfire
, root
);
2114 // Change mount propagation to private
2115 r
= pakfire_mount_change_propagation(jail
->ctx
, root
, MS_PRIVATE
);
2119 // Change root (unless root is /)
2120 if (!pakfire_on_root(jail
->pakfire
)) {
2122 r
= pakfire_jail_mount(jail
, ctx
);
2127 r
= pakfire_jail_switch_root(jail
, root
);
2133 unsigned long persona
= pakfire_arch_personality(arch
);
2135 r
= personality(persona
);
2137 ERROR(jail
->pakfire
, "Could not set personality (%x)\n", (unsigned int)persona
);
2143 if (!pakfire_jail_exec_has_flag(ctx
, PAKFIRE_JAIL_HAS_NETWORKING
)) {
2144 r
= pakfire_jail_setup_loopback(jail
);
2151 DEBUG(jail
->pakfire
, "Setting nice level to %d\n", jail
->nice
);
2153 r
= setpriority(PRIO_PROCESS
, pid
, jail
->nice
);
2155 ERROR(jail
->pakfire
, "Could not set nice level: %m\n");
2160 // Create a new session
2163 CTX_ERROR(jail
->ctx
, "Could not create a new session: %s\n", strerror(errno
));
2167 // Allocate a new PTY
2168 r
= pakfire_jail_open_pty(jail
, ctx
);
2170 CTX_ERROR(jail
->ctx
, "Could not allocate a new PTY: %s\n", strerror(-r
));
2174 // Send the PTY master to the parent process
2175 r
= pakfire_jail_send_fd(jail
, socket_send
, ctx
->pty
.master
.fd
);
2177 CTX_ERROR(jail
->ctx
, "Failed sending the PTY master to the parent: %s\n", strerror(-r
));
2181 // Setup the terminal
2182 r
= pakfire_jail_setup_terminal(jail
, ctx
);
2186 // Close the master of the PTY
2187 close(ctx
->pty
.master
.fd
);
2188 ctx
->pty
.master
.fd
= -1;
2193 // Close other end of log pipes
2194 close(ctx
->pipes
.log_INFO
[0]);
2195 close(ctx
->pipes
.log_ERROR
[0]);
2197 close(ctx
->pipes
.log_DEBUG
[0]);
2198 #endif /* ENABLE_DEBUG */
2200 // Reset open file limit (http://0pointer.net/blog/file-descriptor-limits.html)
2201 r
= pakfire_rlimit_reset_nofile(jail
->pakfire
);
2206 r
= pakfire_jail_set_capabilities(jail
);
2210 // Show capabilities
2211 r
= pakfire_jail_show_capabilities(jail
);
2216 r
= pakfire_jail_limit_syscalls(jail
);
2220 DEBUG(jail
->pakfire
, "Child process initialization done\n");
2221 DEBUG(jail
->pakfire
, "Launching command:\n");
2224 for (unsigned int i
= 0; argv
[i
]; i
++)
2225 DEBUG(jail
->pakfire
, " argv[%u] = %s\n", i
, argv
[i
]);
2228 r
= execvpe(argv
[0], (char**)argv
, jail
->env
);
2230 // Translate errno into regular exit code
2233 // Ignore if the command doesn't exist
2234 if (ctx
->flags
& PAKFIRE_JAIL_NOENT_OK
)
2245 ERROR(jail
->pakfire
, "Could not execve(%s): %m\n", argv
[0]);
2248 // We should not get here
2252 // Run a command in the jail
2253 static int __pakfire_jail_exec(struct pakfire_jail
* jail
, const char* argv
[],
2254 pakfire_jail_communicate_in communicate_in
,
2255 pakfire_jail_communicate_out communicate_out
,
2256 void* data
, int flags
) {
2260 // Check if argv is valid
2261 if (!argv
|| !argv
[0]) {
2266 // Initialize context for this call
2267 struct pakfire_jail_exec ctx
= {
2270 .socket
= { -1, -1 },
2273 .log_INFO
= { -1, -1 },
2274 .log_ERROR
= { -1, -1 },
2276 .log_DEBUG
= { -1, -1 },
2277 #endif /* ENABLE_DEBUG */
2281 .in
= communicate_in
,
2282 .out
= communicate_out
,
2302 DEBUG(jail
->pakfire
, "Executing jail...\n");
2304 // Enable networking in interactive mode
2305 if (ctx
.flags
& PAKFIRE_JAIL_PTY_FORWARDING
)
2306 ctx
.flags
|= PAKFIRE_JAIL_HAS_NETWORKING
;
2309 Setup a file descriptor which can be used to notify the client that the parent
2310 has completed configuration.
2312 ctx
.completed_fd
= eventfd(0, EFD_CLOEXEC
);
2313 if (ctx
.completed_fd
< 0) {
2314 ERROR(jail
->pakfire
, "eventfd() failed: %m\n");
2318 // Create a UNIX domain socket
2319 r
= socketpair(AF_UNIX
, SOCK_DGRAM
|SOCK_CLOEXEC
, 0, ctx
.socket
);
2321 CTX_ERROR(jail
->ctx
, "Could not create UNIX socket: %s\n", strerror(errno
));
2326 // Setup pipes for logging
2328 r
= pakfire_jail_setup_pipe(jail
, &ctx
.pipes
.log_INFO
, O_CLOEXEC
);
2333 r
= pakfire_jail_setup_pipe(jail
, &ctx
.pipes
.log_ERROR
, O_CLOEXEC
);
2339 r
= pakfire_jail_setup_pipe(jail
, &ctx
.pipes
.log_DEBUG
, O_CLOEXEC
);
2342 #endif /* ENABLE_DEBUG */
2344 // Configure child process
2345 struct clone_args args
= {
2355 .exit_signal
= SIGCHLD
,
2356 .pidfd
= (long long unsigned int)&ctx
.pidfd
,
2359 // Launch the process in a cgroup that is a leaf of the configured cgroup
2361 args
.flags
|= CLONE_INTO_CGROUP
;
2364 const char* uuid
= pakfire_jail_uuid(jail
);
2366 // Create a temporary cgroup
2367 r
= pakfire_cgroup_child(&ctx
.cgroup
, jail
->cgroup
, uuid
, 0);
2369 ERROR(jail
->pakfire
, "Could not create cgroup for jail: %m\n");
2373 // Clone into this cgroup
2374 args
.cgroup
= pakfire_cgroup_fd(ctx
.cgroup
);
2378 if (!pakfire_jail_exec_has_flag(&ctx
, PAKFIRE_JAIL_HAS_NETWORKING
)) {
2379 args
.flags
|= CLONE_NEWNET
;
2382 // Fork this process
2383 ctx
.pid
= clone3(&args
, sizeof(args
));
2385 ERROR(jail
->pakfire
, "Could not clone: %m\n");
2389 } else if (ctx
.pid
== 0) {
2390 r
= pakfire_jail_child(jail
, &ctx
, argv
);
2395 r
= pakfire_jail_parent(jail
, &ctx
);
2399 DEBUG(jail
->pakfire
, "Waiting for PID %d to finish its work\n", ctx
.pid
);
2401 // Read output of the child process
2402 r
= pakfire_jail_wait(jail
, &ctx
);
2406 // Handle exit status
2407 switch (ctx
.status
.si_code
) {
2409 DEBUG(jail
->pakfire
, "The child process exited with code %d\n",
2410 ctx
.status
.si_status
);
2413 exit
= ctx
.status
.si_status
;
2417 ERROR(jail
->pakfire
, "The child process was killed\n");
2422 ERROR(jail
->pakfire
, "The child process terminated abnormally\n");
2425 // Log anything else
2427 ERROR(jail
->pakfire
, "Unknown child exit code: %d\n", ctx
.status
.si_code
);
2432 // Destroy the temporary cgroup (if any)
2434 // Read cgroup stats
2435 pakfire_cgroup_stat(ctx
.cgroup
, &ctx
.cgroup_stats
);
2436 pakfire_cgroup_stat_dump(ctx
.cgroup
, &ctx
.cgroup_stats
);
2437 pakfire_cgroup_destroy(ctx
.cgroup
);
2438 pakfire_cgroup_unref(ctx
.cgroup
);
2441 // Close any file descriptors
2444 if (ctx
.pty
.master
.fd
>= 0)
2445 close(ctx
.pty
.master
.fd
);
2446 pakfire_jail_close_pipe(jail
, ctx
.pipes
.log_INFO
);
2447 pakfire_jail_close_pipe(jail
, ctx
.pipes
.log_ERROR
);
2449 pakfire_jail_close_pipe(jail
, ctx
.pipes
.log_DEBUG
);
2450 #endif /* ENABLE_DEBUG */
2451 pakfire_jail_close_pipe(jail
, ctx
.socket
);
2456 PAKFIRE_EXPORT
int pakfire_jail_exec(
2457 struct pakfire_jail
* jail
,
2459 pakfire_jail_communicate_in callback_in
,
2460 pakfire_jail_communicate_out callback_out
,
2461 void* data
, int flags
) {
2462 return __pakfire_jail_exec(jail
, argv
, callback_in
, callback_out
, data
, flags
);
2465 static int pakfire_jail_exec_interactive(
2466 struct pakfire_jail
* jail
, const char* argv
[], int flags
) {
2469 flags
|= PAKFIRE_JAIL_PTY_FORWARDING
;
2471 // Setup interactive stuff
2472 r
= pakfire_jail_setup_interactive_env(jail
);
2476 return __pakfire_jail_exec(jail
, argv
, NULL
, NULL
, NULL
, flags
);
2479 int pakfire_jail_exec_script(struct pakfire_jail
* jail
,
2483 pakfire_jail_communicate_in callback_in
,
2484 pakfire_jail_communicate_out callback_out
,
2486 char path
[PATH_MAX
];
2487 const char** argv
= NULL
;
2491 const char* root
= pakfire_get_path(jail
->pakfire
);
2493 // Write the scriptlet to disk
2494 r
= pakfire_path_append(path
, root
, PAKFIRE_TMP_DIR
"/pakfire-script.XXXXXX");
2498 // Create a temporary file
2499 f
= pakfire_mktemp(path
, 0700);
2501 ERROR(jail
->pakfire
, "Could not create temporary file: %m\n");
2505 DEBUG(jail
->pakfire
, "Writing script to %s:\n%.*s\n", path
, (int)size
, script
);
2508 r
= fprintf(f
, "%s", script
);
2510 ERROR(jail
->pakfire
, "Could not write script to file %s: %m\n", path
);
2517 ERROR(jail
->pakfire
, "Could not close script file %s: %m\n", path
);
2523 // Count how many arguments were passed
2524 unsigned int argc
= 1;
2526 for (const char** arg
= args
; *arg
; arg
++)
2530 argv
= calloc(argc
+ 1, sizeof(*argv
));
2532 ERROR(jail
->pakfire
, "Could not allocate argv: %m\n");
2537 argv
[0] = (root
) ? pakfire_path_relpath(root
, path
) : path
;
2540 for (unsigned int i
= 1; i
< argc
; i
++)
2541 argv
[i
] = args
[i
-1];
2544 r
= pakfire_jail_exec(jail
, argv
, callback_in
, callback_out
, data
, 0);
2552 // Remove script from disk
2560 A convenience function that creates a new jail, runs the given command and destroys
2563 int pakfire_jail_run(struct pakfire
* pakfire
, const char* argv
[], int flags
, char** output
) {
2564 struct pakfire_jail
* jail
= NULL
;
2567 // Create a new jail
2568 r
= pakfire_jail_create(&jail
, pakfire
);
2572 // Execute the command
2573 r
= pakfire_jail_exec(jail
, argv
, NULL
, pakfire_jail_capture_stdout
, output
, 0);
2577 pakfire_jail_unref(jail
);
2582 int pakfire_jail_run_script(struct pakfire
* pakfire
,
2583 const char* script
, const size_t length
, const char* argv
[], int flags
) {
2584 struct pakfire_jail
* jail
= NULL
;
2587 // Create a new jail
2588 r
= pakfire_jail_create(&jail
, pakfire
);
2592 // Execute the command
2593 r
= pakfire_jail_exec_script(jail
, script
, length
, argv
, NULL
, NULL
, NULL
);
2597 pakfire_jail_unref(jail
);
2602 int pakfire_jail_shell(struct pakfire_jail
* jail
) {
2605 const char* argv
[] = {
2606 "/bin/bash", "--login", NULL
,
2609 // Execute /bin/bash
2610 r
= pakfire_jail_exec_interactive(jail
, argv
, 0);
2616 // Ignore any return codes from the shell
2620 static int pakfire_jail_run_if_possible(struct pakfire
* pakfire
, const char** argv
) {
2621 char path
[PATH_MAX
];
2624 r
= pakfire_path(pakfire
, path
, "%s", *argv
);
2628 // Check if the file is executable
2629 r
= access(path
, X_OK
);
2631 DEBUG(pakfire
, "%s is not executable. Skipping...\n", *argv
);
2635 return pakfire_jail_run(pakfire
, argv
, 0, NULL
);
2638 int pakfire_jail_ldconfig(struct pakfire
* pakfire
) {
2639 const char* argv
[] = {
2644 return pakfire_jail_run_if_possible(pakfire
, argv
);
2647 int pakfire_jail_run_systemd_tmpfiles(struct pakfire
* pakfire
) {
2648 const char* argv
[] = {
2649 "/usr/bin/systemd-tmpfiles",
2654 return pakfire_jail_run_if_possible(pakfire
, argv
);