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(struct pakfire_jail
* jail
, int fd
, struct pakfire_log_buffer
* buffer
) {
634 // Nothing to do if the buffer is empty
639 r
= write(fd
, buffer
->data
, buffer
->used
);
654 memmove(buffer
->data
, buffer
->data
+ r
, buffer
->used
- r
);
663 This function reads as much data as it can from the file descriptor.
664 If it finds a whole line in it, it will send it to the logger and repeat the process.
665 If not newline character is found, it will try to read more data until it finds one.
667 static int pakfire_jail_handle_log(struct pakfire_jail
* jail
,
668 struct pakfire_jail_exec
* ctx
, int priority
, int fd
,
669 struct pakfire_log_buffer
* buffer
, pakfire_jail_communicate_out callback
, void* data
) {
670 char line
[BUFFER_SIZE
+ 1];
673 // Fill up buffer from fd
674 r
= pakfire_jail_fill_buffer(jail
, fd
, buffer
);
678 // See if we have any lines that we can write
679 while (buffer
->used
) {
680 // Search for the end of the first line
681 char* eol
= memchr(buffer
->data
, '\n', buffer
->used
);
685 // If the buffer is full, we send the content to the logger and try again
686 // This should not happen in practise
687 if (pakfire_jail_log_buffer_is_full(buffer
)) {
688 DEBUG(jail
->pakfire
, "Logging buffer is full. Sending all content\n");
690 eol
= buffer
->data
+ sizeof(buffer
->data
) - 1;
692 // Otherwise we might have only read parts of the output
697 // Find the length of the string
698 size_t length
= eol
- buffer
->data
+ 1;
700 // Copy the line into the buffer
701 memcpy(line
, buffer
->data
, length
);
703 // Terminate the string
708 r
= callback(jail
->pakfire
, data
, priority
, line
, length
);
710 ERROR(jail
->pakfire
, "The logging callback returned an error: %d\n", r
);
715 // Remove line from buffer
716 memmove(buffer
->data
, buffer
->data
+ length
, buffer
->used
- length
);
717 buffer
->used
-= length
;
724 static int pakfire_jail_stream_stdin(struct pakfire_jail
* jail
,
725 struct pakfire_jail_exec
* ctx
, const int fd
) {
728 // Nothing to do if there is no stdin callback set
729 if (!ctx
->communicate
.in
) {
730 DEBUG(jail
->pakfire
, "Callback for standard input is not set\n");
734 // Skip if the writing pipe has already been closed
735 if (ctx
->pipes
.stdin
[1] < 0)
738 DEBUG(jail
->pakfire
, "Streaming standard input...\n");
740 // Calling the callback
741 r
= ctx
->communicate
.in(jail
->pakfire
, ctx
->communicate
.data
, fd
);
743 DEBUG(jail
->pakfire
, "Standard input callback finished: %d\n", r
);
745 // The callback signaled that it has written everything
747 DEBUG(jail
->pakfire
, "Closing standard input pipe\n");
749 // Close the file-descriptor
752 // Reset the file-descriptor so it won't be closed again later
753 ctx
->pipes
.stdin
[1] = -1;
763 static int pakfire_jail_recv_fd(struct pakfire_jail
* jail
, int socket
, int* fd
) {
764 const size_t payload_length
= sizeof(fd
);
765 char buffer
[CMSG_SPACE(payload_length
)];
768 struct msghdr msg
= {
769 .msg_control
= buffer
,
770 .msg_controllen
= sizeof(buffer
),
773 // Receive the message
774 r
= recvmsg(socket
, &msg
, 0);
776 CTX_ERROR(jail
->ctx
, "Could not receive file descriptor: %s\n", strerror(errno
));
781 struct cmsghdr
* cmsg
= CMSG_FIRSTHDR(&msg
);
785 *fd
= *((int*)CMSG_DATA(cmsg
));
787 CTX_DEBUG(jail
->ctx
, "Received fd %d from socket %d\n", *fd
, socket
);
792 static int pakfire_jail_send_fd(struct pakfire_jail
* jail
, int socket
, int fd
) {
793 const size_t payload_length
= sizeof(fd
);
794 char buffer
[CMSG_SPACE(payload_length
)];
797 CTX_DEBUG(jail
->ctx
, "Sending fd %d to socket %d\n", fd
, socket
);
800 struct msghdr msg
= {
801 .msg_control
= buffer
,
802 .msg_controllen
= sizeof(buffer
),
806 struct cmsghdr
* cmsg
= CMSG_FIRSTHDR(&msg
);
807 cmsg
->cmsg_level
= SOL_SOCKET
;
808 cmsg
->cmsg_type
= SCM_RIGHTS
;
809 cmsg
->cmsg_len
= CMSG_LEN(payload_length
);
812 *((int*)CMSG_DATA(cmsg
)) = fd
;
815 r
= sendmsg(socket
, &msg
, 0);
817 CTX_ERROR(jail
->ctx
, "Could not send file descriptor: %s\n", strerror(errno
));
824 static int pakfire_jail_setup_pipe(struct pakfire_jail
* jail
, int (*fds
)[2], const int flags
) {
825 int r
= pipe2(*fds
, flags
);
827 ERROR(jail
->pakfire
, "Could not setup pipe: %m\n");
834 static void pakfire_jail_close_pipe(struct pakfire_jail
* jail
, int fds
[2]) {
835 for (unsigned int i
= 0; i
< 2; i
++)
841 This is a convenience function to fetch the reading end of a pipe and
842 closes the write end.
844 static int pakfire_jail_get_pipe_to_read(struct pakfire_jail
* jail
, int (*fds
)[2]) {
845 // Give the variables easier names to avoid confusion
846 int* fd_read
= &(*fds
)[0];
847 int* fd_write
= &(*fds
)[1];
849 // Close the write end of the pipe
850 if (*fd_write
>= 0) {
855 // Return the read end
862 static int pakfire_jail_get_pipe_to_write(struct pakfire_jail
* jail
, int (*fds
)[2]) {
863 // Give the variables easier names to avoid confusion
864 int* fd_read
= &(*fds
)[0];
865 int* fd_write
= &(*fds
)[1];
867 // Close the read end of the pipe
873 // Return the write end
880 static int pakfire_jail_log(struct pakfire
* pakfire
, void* data
, int priority
,
881 const char* line
, const size_t length
) {
882 // Pass everything to the parent logger
883 pakfire_log_condition(pakfire
, priority
, 0, "%.*s", (int)length
, line
);
888 static int pakfire_jail_epoll_add_fd(struct pakfire_jail
* jail
, int epollfd
, int fd
, int events
) {
889 struct epoll_event event
= {
890 .events
= events
|EPOLLHUP
,
898 int flags
= fcntl(fd
, F_GETFL
, 0);
900 // Set modified flags
901 r
= fcntl(fd
, F_SETFL
, flags
|O_NONBLOCK
);
903 CTX_ERROR(jail
->ctx
, "Could not set file descriptor %d into non-blocking mode: %s\n",
904 fd
, strerror(errno
));
908 // Add the file descriptor to the loop
909 r
= epoll_ctl(epollfd
, EPOLL_CTL_ADD
, fd
, &event
);
911 ERROR(jail
->pakfire
, "Could not add file descriptor %d to epoll(): %s\n",
912 fd
, strerror(errno
));
921 static int pakfire_jail_enable_raw_mode(struct pakfire_jail
* jail
,
922 struct pakfire_jail_pty_stdio
* stdio
) {
923 struct termios raw_attrs
;
927 stdio
->fdflags
= fcntl(stdio
->fd
, F_GETFL
);
928 if (stdio
->fdflags
< 0) {
929 CTX_ERROR(jail
->ctx
, "Could not fetch flags from fd %d: %s\n",
930 stdio
->fd
, strerror(errno
));
934 // Fetch all attributes
935 r
= tcgetattr(stdio
->fd
, &stdio
->attrs
);
937 CTX_ERROR(jail
->ctx
, "Could not fetch terminal attributes from fd %d: %s\n",
938 stdio
->fd
, strerror(errno
));
942 // Copy all attributes
943 raw_attrs
= stdio
->attrs
;
946 cfmakeraw(&raw_attrs
);
950 raw_attrs
.c_oflag
= stdio
->attrs
.c_oflag
;
954 raw_attrs
.c_iflag
= stdio
->attrs
.c_iflag
;
955 raw_attrs
.c_lflag
= stdio
->attrs
.c_lflag
;
959 // Restore the attributes
960 r
= tcsetattr(stdio
->fd
, TCSANOW
, &raw_attrs
);
962 CTX_ERROR(jail
->ctx
, "Could not restore terminal attributes for fd %d: %s\n",
963 stdio
->fd
, strerror(errno
));
970 static int pakfire_jail_restore_attrs(struct pakfire_jail
* jail
,
971 const struct pakfire_jail_pty_stdio
* stdio
) {
975 r
= fcntl(stdio
->fd
, F_SETFL
, stdio
->fdflags
);
977 CTX_ERROR(jail
->ctx
, "Could not set flags for file descriptor %d: %s\n",
978 stdio
->fd
, strerror(errno
));
982 // Restore the attributes
983 r
= tcsetattr(stdio
->fd
, TCSANOW
, &stdio
->attrs
);
985 CTX_ERROR(jail
->ctx
, "Could not restore terminal attributes for %d, ignoring: %s\n",
986 stdio
->fd
, strerror(errno
));
993 static int pakfire_jail_setup_pty_forwarding(struct pakfire_jail
* jail
,
994 struct pakfire_jail_exec
* ctx
, const int epollfd
, const int fd
) {
998 CTX_DEBUG(jail
->ctx
, "Setting up PTY forwarding on fd %d\n", fd
);
1000 // Store the file descriptor
1001 ctx
->pty
.master
.fd
= fd
;
1003 // Configure stdin/stdout
1004 ctx
->pty
.stdin
.fd
= STDIN_FILENO
;
1005 ctx
->pty
.stdout
.fd
= STDOUT_FILENO
;
1008 r
= ioctl(ctx
->pty
.stdout
.fd
, TIOCGWINSZ
, &size
);
1010 CTX_ERROR(jail
->ctx
, "Failed to determine terminal dimensions: %s\n", strerror(errno
));
1015 r
= ioctl(ctx
->pty
.master
.fd
, TIOCSWINSZ
, &size
);
1017 CTX_ERROR(jail
->ctx
, "Failed setting dimensions: %s\n", strerror(errno
));
1021 // Enable RAW mode on standard input
1022 r
= pakfire_jail_enable_raw_mode(jail
, &ctx
->pty
.stdin
);
1026 // Enable RAW mode on standard output
1027 r
= pakfire_jail_enable_raw_mode(jail
, &ctx
->pty
.stdout
);
1031 // Add the master to the event loop
1032 r
= pakfire_jail_epoll_add_fd(jail
, epollfd
, ctx
->pty
.master
.fd
, EPOLLIN
|EPOLLOUT
|EPOLLET
);
1036 // Add standard input to the event loop
1037 r
= pakfire_jail_epoll_add_fd(jail
, epollfd
, ctx
->pty
.stdin
.fd
, EPOLLIN
|EPOLLET
);
1041 // Add standard output to the event loop
1042 r
= pakfire_jail_epoll_add_fd(jail
, epollfd
, ctx
->pty
.stdout
.fd
, EPOLLOUT
|EPOLLET
);
1049 static int pakfire_jail_forward_pty(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1052 // Read from standard input
1053 if (ctx
->pty
.stdin
.flags
& PAKFIRE_JAIL_PTY_READY_TO_READ
) {
1054 r
= pakfire_jail_fill_buffer(jail
, ctx
->pty
.stdin
.fd
, &ctx
->pty
.stdin
.buffer
);
1056 CTX_ERROR(jail
->ctx
, "Failed reading from standard input: %s\n", strerror(-r
));
1060 // We are done reading for now
1061 ctx
->pty
.stdin
.flags
&= ~PAKFIRE_JAIL_PTY_READY_TO_READ
;
1063 // But we may have data to write
1064 if (ctx
->pty
.stdin
.buffer
.used
)
1065 ctx
->pty
.master
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1068 // Write to the master
1069 if (ctx
->pty
.master
.flags
& PAKFIRE_JAIL_PTY_READY_TO_WRITE
) {
1070 r
= pakfire_jail_drain_buffer(jail
, ctx
->pty
.master
.fd
, &ctx
->pty
.stdin
.buffer
);
1072 CTX_ERROR(jail
->ctx
, "Failed writing to the PTY: %s\n", strerror(-r
));
1076 // We are done writing for now
1077 ctx
->pty
.master
.flags
&= ~PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1080 // Read from the master
1081 if (ctx
->pty
.master
.flags
& PAKFIRE_JAIL_PTY_READY_TO_READ
) {
1082 r
= pakfire_jail_fill_buffer(jail
, ctx
->pty
.master
.fd
, &ctx
->pty
.stdout
.buffer
);
1084 CTX_ERROR(jail
->ctx
, "Failed reading from the PTY: %s\n", strerror(-r
));
1088 // We are done reading for now
1089 ctx
->pty
.master
.flags
&= ~PAKFIRE_JAIL_PTY_READY_TO_READ
;
1091 // But we may have data to write
1092 if (ctx
->pty
.stdout
.buffer
.used
)
1093 ctx
->pty
.stdout
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1096 // Write to standard output
1097 if (ctx
->pty
.stdout
.flags
& PAKFIRE_JAIL_PTY_READY_TO_WRITE
) {
1098 r
= pakfire_jail_drain_buffer(jail
, ctx
->pty
.stdout
.fd
, &ctx
->pty
.stdout
.buffer
);
1100 CTX_ERROR(jail
->ctx
, "Failed writing to standard output: %s\n", strerror(-r
));
1104 // We are done writing for now
1105 ctx
->pty
.stdout
.flags
&= ~PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1111 static int pakfire_jail_wait(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1113 struct epoll_event events
[EPOLL_MAX_EVENTS
];
1117 // Fetch file descriptors from context
1118 const int pidfd
= ctx
->pidfd
;
1120 // Fetch the UNIX domain socket
1121 const int socket_recv
= pakfire_jail_get_pipe_to_read(jail
, &ctx
->socket
);
1124 const int timerfd
= pakfire_jail_create_timer(jail
);
1127 const int log_INFO
= pakfire_jail_get_pipe_to_read(jail
, &ctx
->pipes
.log_INFO
);
1128 const int log_ERROR
= pakfire_jail_get_pipe_to_read(jail
, &ctx
->pipes
.log_ERROR
);
1130 const int log_DEBUG
= pakfire_jail_get_pipe_to_read(jail
, &ctx
->pipes
.log_DEBUG
);
1131 #endif /* ENABLE_DEBUG */
1133 // Make a list of all file descriptors we are interested in
1134 const struct pakfire_wait_fds
{
1139 { timerfd
, EPOLLIN
},
1142 { ctx
->pidfd
, EPOLLIN
},
1145 { log_INFO
, EPOLLIN
},
1146 { log_ERROR
, EPOLLIN
},
1148 { log_DEBUG
, EPOLLIN
},
1149 #endif /* ENABLE_DEBUG */
1151 // UNIX Domain Socket
1152 { socket_recv
, EPOLLIN
},
1159 epollfd
= epoll_create1(0);
1161 ERROR(jail
->pakfire
, "Could not initialize epoll(): %m\n");
1166 // Turn file descriptors into non-blocking mode and add them to epoll()
1167 for (const struct pakfire_wait_fds
* fd
= fds
; fd
->events
; fd
++) {
1168 // Skip fds which were not initialized
1172 // Add the FD to the event loop
1173 r
= pakfire_jail_epoll_add_fd(jail
, epollfd
, fd
->fd
, fd
->events
);
1180 // Loop for as long as the process is alive
1182 int num
= epoll_wait(epollfd
, events
, EPOLL_MAX_EVENTS
, -1);
1184 // Ignore if epoll_wait() has been interrupted
1188 ERROR(jail
->pakfire
, "epoll_wait() failed: %m\n");
1194 for (int i
= 0; i
< num
; i
++) {
1195 int e
= events
[i
].events
;
1196 int fd
= events
[i
].data
.fd
;
1198 // Handle PTY forwarding events
1199 if (ctx
->pty
.master
.fd
== fd
) {
1200 if (e
& (EPOLLIN
|EPOLLHUP
))
1201 ctx
->pty
.master
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_READ
;
1203 if (e
& (EPOLLOUT
|EPOLLHUP
))
1204 ctx
->pty
.master
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1207 r
= pakfire_jail_forward_pty(jail
, ctx
);
1209 CTX_ERROR(jail
->ctx
, "Failed forwarding the PTY: %s\n", strerror(-r
));
1213 // Handle standard input
1214 } else if (ctx
->pty
.stdin
.fd
== fd
) {
1215 if (e
& (EPOLLIN
|EPOLLHUP
))
1216 ctx
->pty
.stdin
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_READ
;
1219 r
= pakfire_jail_forward_pty(jail
, ctx
);
1221 CTX_ERROR(jail
->ctx
, "Failed forwarding the PTY: %s\n", strerror(-r
));
1225 // Handle standard output
1226 } else if (ctx
->pty
.stdout
.fd
== fd
) {
1227 if (e
& (EPOLLOUT
|EPOLLHUP
))
1228 ctx
->pty
.stdout
.flags
|= PAKFIRE_JAIL_PTY_READY_TO_WRITE
;
1231 r
= pakfire_jail_forward_pty(jail
, ctx
);
1233 CTX_ERROR(jail
->ctx
, "Failed forwarding the PTY: %s\n", strerror(-r
));
1237 // Handle any changes to the PIDFD
1238 } else if (pidfd
== fd
) {
1240 // Call waidid() and store the result
1241 r
= waitid(P_PIDFD
, ctx
->pidfd
, &ctx
->status
, WEXITED
);
1243 ERROR(jail
->pakfire
, "waitid() failed: %m\n");
1247 // Mark that we have ended so that we will process the remaining
1248 // events from epoll() now, but won't restart the outer loop.
1252 // Handle timer events
1253 } else if (timerfd
== fd
) {
1255 DEBUG(jail
->pakfire
, "Timer event received\n");
1258 r
= read(timerfd
, garbage
, sizeof(garbage
));
1260 ERROR(jail
->pakfire
, "Could not disarm timer: %m\n");
1265 // Terminate the process if it hasn't already ended
1267 DEBUG(jail
->pakfire
, "Terminating process...\n");
1269 // Send SIGTERM to the process
1270 r
= pidfd_send_signal(pidfd
, SIGKILL
, NULL
, 0);
1272 ERROR(jail
->pakfire
, "Could not kill process: %m\n");
1278 // Handle socket messages
1279 } else if (socket_recv
== fd
) {
1281 // Receive the passed FD
1282 r
= pakfire_jail_recv_fd(jail
, socket_recv
, &fd
);
1286 // Setup PTY forwarding
1287 if (ctx
->pty
.master
.fd
< 0) {
1288 r
= pakfire_jail_setup_pty_forwarding(jail
, ctx
, epollfd
, fd
);
1290 CTX_ERROR(jail
->ctx
, "Failed setting up PTY forwarding: %s\n", strerror(-r
));
1296 // Handle log INFO messages
1297 } else if (log_INFO
== fd
) {
1299 r
= pakfire_jail_handle_log(jail
, ctx
, LOG_INFO
, fd
,
1300 &ctx
->buffers
.log_INFO
, pakfire_jail_log
, NULL
);
1305 // Handle log ERROR messages
1306 } else if (log_ERROR
== fd
) {
1308 r
= pakfire_jail_handle_log(jail
, ctx
, LOG_ERR
, fd
,
1309 &ctx
->buffers
.log_ERROR
, pakfire_jail_log
, NULL
);
1315 // Handle log DEBUG messages
1316 } else if (log_DEBUG
== fd
) {
1318 r
= pakfire_jail_handle_log(jail
, ctx
, LOG_DEBUG
, fd
,
1319 &ctx
->buffers
.log_DEBUG
, pakfire_jail_log
, NULL
);
1323 #endif /* ENABLE_DEBUG */
1325 // Log a message for anything else
1327 DEBUG(jail
->pakfire
, "Received invalid file descriptor %d\n", fd
);
1331 // Check if any file descriptors have been closed
1333 // Remove the file descriptor
1334 r
= epoll_ctl(epollfd
, EPOLL_CTL_DEL
, fd
, NULL
);
1336 ERROR(jail
->pakfire
, "Could not remove closed file-descriptor %d: %m\n", fd
);
1349 // Restore any changed terminal attributes
1350 if (ctx
->pty
.stdin
.fd
>= 0)
1351 pakfire_jail_restore_attrs(jail
, &ctx
->pty
.stdin
);
1352 if (ctx
->pty
.stdout
.fd
>= 0)
1353 pakfire_jail_restore_attrs(jail
, &ctx
->pty
.stdout
);
1358 int pakfire_jail_capture_stdout(struct pakfire
* pakfire
, void* data
,
1359 int priority
, const char* line
, size_t length
) {
1360 char** output
= (char**)data
;
1363 // Append everything from stdout to a buffer
1364 if (output
&& priority
== LOG_INFO
) {
1365 r
= asprintf(output
, "%s%s", (output
&& *output
) ? *output
: "", line
);
1371 // Send everything else to the default logger
1372 return pakfire_jail_default_log_callback(pakfire
, NULL
, priority
, line
, length
);
1377 // Logs all capabilities of the current process
1378 static int pakfire_jail_show_capabilities(struct pakfire_jail
* jail
) {
1381 cap_flag_value_t value_e
;
1382 cap_flag_value_t value_i
;
1383 cap_flag_value_t value_p
;
1387 pid_t pid
= getpid();
1389 // Fetch all capabilities
1390 caps
= cap_get_proc();
1392 ERROR(jail
->pakfire
, "Could not fetch capabilities: %m\n");
1397 DEBUG(jail
->pakfire
, "Capabilities of PID %d:\n", pid
);
1399 // Iterate over all capabilities
1400 for (unsigned int cap
= 0; cap_valid(cap
); cap
++) {
1401 name
= cap_to_name(cap
);
1403 // Fetch effective value
1404 r
= cap_get_flag(caps
, cap
, CAP_EFFECTIVE
, &value_e
);
1408 // Fetch inheritable value
1409 r
= cap_get_flag(caps
, cap
, CAP_INHERITABLE
, &value_i
);
1413 // Fetch permitted value
1414 r
= cap_get_flag(caps
, cap
, CAP_PERMITTED
, &value_p
);
1418 DEBUG(jail
->pakfire
,
1419 " %-24s : %c%c%c\n",
1421 (value_e
== CAP_SET
) ? 'e' : '-',
1422 (value_i
== CAP_SET
) ? 'i' : '-',
1423 (value_p
== CAP_SET
) ? 'p' : '-'
1443 static int pakfire_jail_set_capabilities(struct pakfire_jail
* jail
) {
1448 // Fetch capabilities
1449 caps
= cap_get_proc();
1451 ERROR(jail
->pakfire
, "Could not read capabilities: %m\n");
1456 // Walk through all capabilities
1457 for (cap_value_t cap
= 0; cap_valid(cap
); cap
++) {
1458 cap_value_t _caps
[] = { cap
};
1460 // Fetch the name of the capability
1461 name
= cap_to_name(cap
);
1463 r
= cap_set_flag(caps
, CAP_EFFECTIVE
, 1, _caps
, CAP_SET
);
1465 ERROR(jail
->pakfire
, "Could not set %s: %m\n", name
);
1469 r
= cap_set_flag(caps
, CAP_INHERITABLE
, 1, _caps
, CAP_SET
);
1471 ERROR(jail
->pakfire
, "Could not set %s: %m\n", name
);
1475 r
= cap_set_flag(caps
, CAP_PERMITTED
, 1, _caps
, CAP_SET
);
1477 ERROR(jail
->pakfire
, "Could not set %s: %m\n", name
);
1486 // Restore all capabilities
1487 r
= cap_set_proc(caps
);
1489 ERROR(jail
->pakfire
, "Restoring capabilities failed: %m\n");
1493 // Add all capabilities to the ambient set
1494 for (unsigned int cap
= 0; cap_valid(cap
); cap
++) {
1495 name
= cap_to_name(cap
);
1497 // Raise the capability
1498 r
= prctl(PR_CAP_AMBIENT
, PR_CAP_AMBIENT_RAISE
, cap
, 0, 0);
1500 ERROR(jail
->pakfire
, "Could not set ambient capability %s: %m\n", name
);
1523 static int pakfire_jail_limit_syscalls(struct pakfire_jail
* jail
) {
1524 const int syscalls
[] = {
1525 // The kernel's keyring isn't namespaced
1528 SCMP_SYS(request_key
),
1530 // Disable userfaultfd
1531 SCMP_SYS(userfaultfd
),
1533 // Disable perf which could leak a lot of information about the host
1534 SCMP_SYS(perf_event_open
),
1540 DEBUG(jail
->pakfire
, "Applying syscall filter...\n");
1542 // Setup a syscall filter which allows everything by default
1543 scmp_filter_ctx ctx
= seccomp_init(SCMP_ACT_ALLOW
);
1545 ERROR(jail
->pakfire
, "Could not setup seccomp filter: %m\n");
1550 for (const int* syscall
= syscalls
; *syscall
; syscall
++) {
1551 r
= seccomp_rule_add(ctx
, SCMP_ACT_ERRNO(EPERM
), *syscall
, 0);
1553 ERROR(jail
->pakfire
, "Could not configure syscall %d: %m\n", *syscall
);
1558 // Load syscall filter into the kernel
1559 r
= seccomp_load(ctx
);
1561 ERROR(jail
->pakfire
, "Could not load syscall filter into the kernel: %m\n");
1567 seccomp_release(ctx
);
1574 PAKFIRE_EXPORT
int pakfire_jail_bind(struct pakfire_jail
* jail
,
1575 const char* source
, const char* target
, int flags
) {
1576 struct pakfire_jail_mountpoint
* mp
= NULL
;
1579 // Check if there is any space left
1580 if (jail
->num_mountpoints
>= MAX_MOUNTPOINTS
) {
1585 // Check for valid inputs
1586 if (!source
|| !target
) {
1591 // Select the next free slot
1592 mp
= &jail
->mountpoints
[jail
->num_mountpoints
];
1595 r
= pakfire_string_set(mp
->source
, source
);
1597 ERROR(jail
->pakfire
, "Could not copy source: %m\n");
1602 r
= pakfire_string_set(mp
->target
, target
);
1604 ERROR(jail
->pakfire
, "Could not copy target: %m\n");
1611 // Increment counter
1612 jail
->num_mountpoints
++;
1617 static int pakfire_jail_mount_networking(struct pakfire_jail
* jail
) {
1620 const char* paths
[] = {
1626 // Bind-mount all paths read-only
1627 for (const char** path
= paths
; *path
; path
++) {
1628 r
= pakfire_bind(jail
->pakfire
, *path
, NULL
, MS_RDONLY
);
1631 // Ignore if we don't have permission
1646 Mounts everything that we require in the new namespace
1648 static int pakfire_jail_mount(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1649 struct pakfire_jail_mountpoint
* mp
= NULL
;
1653 // Enable loop devices
1654 if (pakfire_jail_exec_has_flag(ctx
, PAKFIRE_JAIL_HAS_LOOP_DEVICES
))
1655 flags
|= PAKFIRE_MOUNT_LOOP_DEVICES
;
1657 // Mount all default stuff
1658 r
= pakfire_mount_all(jail
->pakfire
, PAKFIRE_MNTNS_OUTER
, flags
);
1663 r
= pakfire_populate_dev(jail
->pakfire
, flags
);
1667 // Mount the interpreter (if needed)
1668 r
= pakfire_mount_interpreter(jail
->pakfire
);
1672 // Mount networking stuff
1673 if (pakfire_jail_exec_has_flag(ctx
, PAKFIRE_JAIL_HAS_NETWORKING
)) {
1674 r
= pakfire_jail_mount_networking(jail
);
1679 // Mount all custom stuff
1680 for (unsigned int i
= 0; i
< jail
->num_mountpoints
; i
++) {
1682 mp
= &jail
->mountpoints
[i
];
1685 r
= pakfire_bind(jail
->pakfire
, mp
->source
, mp
->target
, mp
->flags
);
1695 static int pakfire_jail_setup_loopback(struct pakfire_jail
* jail
) {
1696 struct nl_sock
* nl
= NULL
;
1697 struct nl_cache
* cache
= NULL
;
1698 struct rtnl_link
* link
= NULL
;
1699 struct rtnl_link
* change
= NULL
;
1702 DEBUG(jail
->pakfire
, "Setting up loopback...\n");
1704 // Allocate a netlink socket
1705 nl
= nl_socket_alloc();
1707 ERROR(jail
->pakfire
, "Could not allocate a netlink socket: %m\n");
1712 // Connect the socket
1713 r
= nl_connect(nl
, NETLINK_ROUTE
);
1715 ERROR(jail
->pakfire
, "Could not connect netlink socket: %s\n", nl_geterror(r
));
1719 // Allocate the netlink cache
1720 r
= rtnl_link_alloc_cache(nl
, AF_UNSPEC
, &cache
);
1722 ERROR(jail
->pakfire
, "Unable to allocate netlink cache: %s\n", nl_geterror(r
));
1726 // Fetch loopback interface
1727 link
= rtnl_link_get_by_name(cache
, "lo");
1729 ERROR(jail
->pakfire
, "Could not find lo interface. Ignoring.\n");
1734 // Allocate a new link
1735 change
= rtnl_link_alloc();
1737 ERROR(jail
->pakfire
, "Could not allocate change link\n");
1742 // Set the link to UP
1743 rtnl_link_set_flags(change
, IFF_UP
);
1745 // Apply any changes
1746 r
= rtnl_link_change(nl
, link
, change
, 0);
1748 ERROR(jail
->pakfire
, "Unable to activate loopback: %s\n", nl_geterror(r
));
1764 static int pakfire_jail_setup_uid_mapping(struct pakfire_jail
* jail
, pid_t pid
) {
1765 char path
[PATH_MAX
];
1768 // Skip mapping anything when running on /
1769 if (pakfire_on_root(jail
->pakfire
))
1773 r
= pakfire_string_format(path
, "/proc/%d/uid_map", pid
);
1778 const uid_t uid
= pakfire_uid(jail
->pakfire
);
1781 const struct pakfire_subid
* subuid
= pakfire_subuid(jail
->pakfire
);
1785 /* When running as root, we will map the entire range.
1787 When running as a non-privileged user, we will map the root user inside the jail
1788 to the user's UID outside of the jail, and we will map the rest starting from one.
1793 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0,
1794 "0 %lu %lu\n", subuid
->id
, subuid
->length
);
1796 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0,
1797 "0 %lu 1\n1 %lu %lu\n", uid
, subuid
->id
, subuid
->length
);
1801 ERROR(jail
->pakfire
, "Could not map UIDs: %m\n");
1808 static int pakfire_jail_setup_gid_mapping(struct pakfire_jail
* jail
, pid_t pid
) {
1809 char path
[PATH_MAX
];
1812 // Skip mapping anything when running on /
1813 if (pakfire_on_root(jail
->pakfire
))
1817 const gid_t gid
= pakfire_gid(jail
->pakfire
);
1820 const struct pakfire_subid
* subgid
= pakfire_subgid(jail
->pakfire
);
1825 r
= pakfire_string_format(path
, "/proc/%d/gid_map", pid
);
1831 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0,
1832 "0 %lu %lu\n", subgid
->id
, subgid
->length
);
1834 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0,
1835 "0 %lu 1\n1 %lu %lu\n", gid
, subgid
->id
, subgid
->length
);
1839 ERROR(jail
->pakfire
, "Could not map GIDs: %m\n");
1846 static int pakfire_jail_setgroups(struct pakfire_jail
* jail
, pid_t pid
) {
1847 char path
[PATH_MAX
];
1851 r
= pakfire_string_format(path
, "/proc/%d/setgroups", pid
);
1855 r
= pakfire_file_write(jail
->pakfire
, path
, 0, 0, 0, "deny\n");
1857 CTX_ERROR(jail
->ctx
, "Could not set setgroups to deny: %s\n", strerror(errno
));
1864 static int pakfire_jail_send_signal(struct pakfire_jail
* jail
, int fd
) {
1865 const uint64_t val
= 1;
1868 DEBUG(jail
->pakfire
, "Sending signal...\n");
1870 // Write to the file descriptor
1871 r
= eventfd_write(fd
, val
);
1873 ERROR(jail
->pakfire
, "Could not send signal: %s\n", strerror(errno
));
1877 // Close the file descriptor
1883 static int pakfire_jail_wait_for_signal(struct pakfire_jail
* jail
, int fd
) {
1887 DEBUG(jail
->pakfire
, "Waiting for signal...\n");
1889 r
= eventfd_read(fd
, &val
);
1891 ERROR(jail
->pakfire
, "Error waiting for signal: %s\n", strerror(errno
));
1895 // Close the file descriptor
1902 Performs the initialisation that needs to happen in the parent part
1904 static int pakfire_jail_parent(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1907 // Setup UID mapping
1908 r
= pakfire_jail_setup_uid_mapping(jail
, ctx
->pid
);
1912 // Write "deny" to /proc/PID/setgroups
1913 r
= pakfire_jail_setgroups(jail
, ctx
->pid
);
1917 // Setup GID mapping
1918 r
= pakfire_jail_setup_gid_mapping(jail
, ctx
->pid
);
1922 // Parent has finished initialisation
1923 DEBUG(jail
->pakfire
, "Parent has finished initialization\n");
1925 // Send signal to client
1926 r
= pakfire_jail_send_signal(jail
, ctx
->completed_fd
);
1933 static int pakfire_jail_switch_root(struct pakfire_jail
* jail
, const char* root
) {
1936 // Change to the new root
1939 ERROR(jail
->pakfire
, "chdir(%s) failed: %m\n", root
);
1944 r
= pivot_root(".", ".");
1946 ERROR(jail
->pakfire
, "Failed changing into the new root directory %s: %m\n", root
);
1950 // Umount the old root
1951 r
= umount2(".", MNT_DETACH
);
1953 ERROR(jail
->pakfire
, "Could not umount the old root filesystem: %m\n");
1960 static int pakfire_jail_open_pty(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1963 // Allocate a new PTY
1964 ctx
->pty
.master
.fd
= posix_openpt(O_RDWR
|O_NONBLOCK
|O_NOCTTY
|O_CLOEXEC
);
1965 if (ctx
->pty
.master
.fd
< 0)
1969 r
= ptsname_r(ctx
->pty
.master
.fd
, ctx
->pty
.console
, sizeof(ctx
->pty
.console
));
1973 CTX_DEBUG(jail
->ctx
, "Allocated console at %s (%d)\n", ctx
->pty
.console
, ctx
->pty
.master
.fd
);
1975 // Unlock the master device
1976 r
= unlockpt(ctx
->pty
.master
.fd
);
1978 CTX_ERROR(jail
->ctx
, "Could not unlock the PTY: %s\n", strerror(errno
));
1983 r
= pakfire_symlink(jail
->ctx
, ctx
->pty
.console
, "/dev/console");
1990 static int pakfire_jail_setup_terminal(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
) {
1994 // Open a new terminal
1995 fd
= open("/dev/console", O_RDWR
|O_NOCTTY
);
1997 CTX_ERROR(jail
->ctx
, "Failed to open a new terminal: %s\n", strerror(errno
));
2001 CTX_DEBUG(jail
->ctx
, "Opened a new terminal %d\n", fd
);
2003 // Connect the new terminal to standard input
2004 r
= dup2(fd
, STDIN_FILENO
);
2006 CTX_ERROR(jail
->ctx
, "Failed to open standard input: %s\n", strerror(errno
));
2010 // Connect the new terminal to standard output
2011 r
= dup2(fd
, STDOUT_FILENO
);
2013 CTX_ERROR(jail
->ctx
, "Failed to open standard output: %s\n", strerror(errno
));
2017 // Connect the new terminal to standard error
2018 r
= dup2(fd
, STDERR_FILENO
);
2020 CTX_ERROR(jail
->ctx
, "Failed to open standard error: %s\n", strerror(errno
));
2027 static int pakfire_jail_child(struct pakfire_jail
* jail
, struct pakfire_jail_exec
* ctx
,
2028 const char* argv
[]) {
2031 // Redirect any logging to our log pipe
2032 pakfire_ctx_set_log_callback(jail
->ctx
, pakfire_jail_log_redirect
, &ctx
->pipes
);
2035 pid_t pid
= getpid();
2037 DEBUG(jail
->pakfire
, "Launched child process in jail with PID %d\n", pid
);
2039 // Wait for the parent to finish initialization
2040 r
= pakfire_jail_wait_for_signal(jail
, ctx
->completed_fd
);
2045 r
= prctl(PR_SET_PDEATHSIG
, SIGKILL
, 0, 0, 0);
2047 ERROR(jail
->pakfire
, "Could not configure to die with parent: %m\n");
2051 // Make this process dumpable
2052 r
= prctl (PR_SET_DUMPABLE
, 1, 0, 0, 0);
2054 ERROR(jail
->pakfire
, "Could not make the process dumpable: %m\n");
2058 // Don't drop any capabilities on setuid()
2059 r
= prctl(PR_SET_KEEPCAPS
, 1);
2061 ERROR(jail
->pakfire
, "Could not set PR_SET_KEEPCAPS: %m\n");
2066 uid_t uid
= getuid();
2067 gid_t gid
= getgid();
2070 uid_t euid
= geteuid();
2071 gid_t egid
= getegid();
2073 DEBUG(jail
->pakfire
, " UID: %u (effective %u)\n", uid
, euid
);
2074 DEBUG(jail
->pakfire
, " GID: %u (effective %u)\n", gid
, egid
);
2076 // Log all mountpoints
2077 pakfire_mount_list(jail
->ctx
);
2079 // Fail if we are not PID 1
2081 CTX_ERROR(jail
->ctx
, "Child process is not PID 1\n");
2085 // Fail if we are not running as root
2086 if (uid
|| gid
|| euid
|| egid
) {
2087 ERROR(jail
->pakfire
, "Child process is not running as root\n");
2091 const int socket_send
= pakfire_jail_get_pipe_to_write(jail
, &ctx
->socket
);
2093 // Mount all default stuff
2094 r
= pakfire_mount_all(jail
->pakfire
, PAKFIRE_MNTNS_INNER
, 0);
2098 const char* root
= pakfire_get_path(jail
->pakfire
);
2099 const char* arch
= pakfire_get_effective_arch(jail
->pakfire
);
2101 // Change mount propagation to slave to receive anything from the parent namespace
2102 r
= pakfire_mount_change_propagation(jail
->ctx
, "/", MS_SLAVE
);
2106 // Make root a mountpoint in the new mount namespace
2107 r
= pakfire_mount_make_mounpoint(jail
->pakfire
, root
);
2111 // Change mount propagation to private
2112 r
= pakfire_mount_change_propagation(jail
->ctx
, root
, MS_PRIVATE
);
2116 // Change root (unless root is /)
2117 if (!pakfire_on_root(jail
->pakfire
)) {
2119 r
= pakfire_jail_mount(jail
, ctx
);
2124 r
= pakfire_jail_switch_root(jail
, root
);
2130 unsigned long persona
= pakfire_arch_personality(arch
);
2132 r
= personality(persona
);
2134 ERROR(jail
->pakfire
, "Could not set personality (%x)\n", (unsigned int)persona
);
2140 if (!pakfire_jail_exec_has_flag(ctx
, PAKFIRE_JAIL_HAS_NETWORKING
)) {
2141 r
= pakfire_jail_setup_loopback(jail
);
2148 DEBUG(jail
->pakfire
, "Setting nice level to %d\n", jail
->nice
);
2150 r
= setpriority(PRIO_PROCESS
, pid
, jail
->nice
);
2152 ERROR(jail
->pakfire
, "Could not set nice level: %m\n");
2157 // Create a new session
2160 CTX_ERROR(jail
->ctx
, "Could not create a new session: %s\n", strerror(errno
));
2164 // Allocate a new PTY
2165 r
= pakfire_jail_open_pty(jail
, ctx
);
2167 CTX_ERROR(jail
->ctx
, "Could not allocate a new PTY: %s\n", strerror(-r
));
2171 // Send the PTY master to the parent process
2172 r
= pakfire_jail_send_fd(jail
, socket_send
, ctx
->pty
.master
.fd
);
2174 CTX_ERROR(jail
->ctx
, "Failed sending the PTY master to the parent: %s\n", strerror(-r
));
2178 // Setup the terminal
2179 r
= pakfire_jail_setup_terminal(jail
, ctx
);
2183 // Close the master of the PTY
2184 close(ctx
->pty
.master
.fd
);
2185 ctx
->pty
.master
.fd
= -1;
2190 // Close other end of log pipes
2191 close(ctx
->pipes
.log_INFO
[0]);
2192 close(ctx
->pipes
.log_ERROR
[0]);
2194 close(ctx
->pipes
.log_DEBUG
[0]);
2195 #endif /* ENABLE_DEBUG */
2197 // Reset open file limit (http://0pointer.net/blog/file-descriptor-limits.html)
2198 r
= pakfire_rlimit_reset_nofile(jail
->pakfire
);
2203 r
= pakfire_jail_set_capabilities(jail
);
2207 // Show capabilities
2208 r
= pakfire_jail_show_capabilities(jail
);
2213 r
= pakfire_jail_limit_syscalls(jail
);
2217 DEBUG(jail
->pakfire
, "Child process initialization done\n");
2218 DEBUG(jail
->pakfire
, "Launching command:\n");
2221 for (unsigned int i
= 0; argv
[i
]; i
++)
2222 DEBUG(jail
->pakfire
, " argv[%u] = %s\n", i
, argv
[i
]);
2225 r
= execvpe(argv
[0], (char**)argv
, jail
->env
);
2227 // Translate errno into regular exit code
2230 // Ignore if the command doesn't exist
2231 if (ctx
->flags
& PAKFIRE_JAIL_NOENT_OK
)
2242 ERROR(jail
->pakfire
, "Could not execve(%s): %m\n", argv
[0]);
2245 // We should not get here
2249 // Run a command in the jail
2250 static int __pakfire_jail_exec(struct pakfire_jail
* jail
, const char* argv
[],
2251 const int interactive
,
2252 pakfire_jail_communicate_in communicate_in
,
2253 pakfire_jail_communicate_out communicate_out
,
2254 void* data
, int flags
) {
2258 // Check if argv is valid
2259 if (!argv
|| !argv
[0]) {
2264 // Initialize context for this call
2265 struct pakfire_jail_exec ctx
= {
2268 .socket
= { -1, -1 },
2271 .log_INFO
= { -1, -1 },
2272 .log_ERROR
= { -1, -1 },
2274 .log_DEBUG
= { -1, -1 },
2275 #endif /* ENABLE_DEBUG */
2279 .in
= communicate_in
,
2280 .out
= communicate_out
,
2300 DEBUG(jail
->pakfire
, "Executing jail...\n");
2302 // Enable networking in interactive mode
2304 ctx
.flags
|= PAKFIRE_JAIL_HAS_NETWORKING
;
2307 Setup a file descriptor which can be used to notify the client that the parent
2308 has completed configuration.
2310 ctx
.completed_fd
= eventfd(0, EFD_CLOEXEC
);
2311 if (ctx
.completed_fd
< 0) {
2312 ERROR(jail
->pakfire
, "eventfd() failed: %m\n");
2316 // Create a UNIX domain socket
2317 r
= socketpair(AF_UNIX
, SOCK_DGRAM
|SOCK_CLOEXEC
, 0, ctx
.socket
);
2319 CTX_ERROR(jail
->ctx
, "Could not create UNIX socket: %s\n", strerror(errno
));
2324 // Setup pipes for logging
2326 r
= pakfire_jail_setup_pipe(jail
, &ctx
.pipes
.log_INFO
, O_CLOEXEC
);
2331 r
= pakfire_jail_setup_pipe(jail
, &ctx
.pipes
.log_ERROR
, O_CLOEXEC
);
2337 r
= pakfire_jail_setup_pipe(jail
, &ctx
.pipes
.log_DEBUG
, O_CLOEXEC
);
2340 #endif /* ENABLE_DEBUG */
2342 // Configure child process
2343 struct clone_args args
= {
2353 .exit_signal
= SIGCHLD
,
2354 .pidfd
= (long long unsigned int)&ctx
.pidfd
,
2357 // Launch the process in a cgroup that is a leaf of the configured cgroup
2359 args
.flags
|= CLONE_INTO_CGROUP
;
2362 const char* uuid
= pakfire_jail_uuid(jail
);
2364 // Create a temporary cgroup
2365 r
= pakfire_cgroup_child(&ctx
.cgroup
, jail
->cgroup
, uuid
, 0);
2367 ERROR(jail
->pakfire
, "Could not create cgroup for jail: %m\n");
2371 // Clone into this cgroup
2372 args
.cgroup
= pakfire_cgroup_fd(ctx
.cgroup
);
2376 if (!pakfire_jail_exec_has_flag(&ctx
, PAKFIRE_JAIL_HAS_NETWORKING
)) {
2377 args
.flags
|= CLONE_NEWNET
;
2380 // Fork this process
2381 ctx
.pid
= clone3(&args
, sizeof(args
));
2383 ERROR(jail
->pakfire
, "Could not clone: %m\n");
2387 } else if (ctx
.pid
== 0) {
2388 r
= pakfire_jail_child(jail
, &ctx
, argv
);
2393 r
= pakfire_jail_parent(jail
, &ctx
);
2397 DEBUG(jail
->pakfire
, "Waiting for PID %d to finish its work\n", ctx
.pid
);
2399 // Read output of the child process
2400 r
= pakfire_jail_wait(jail
, &ctx
);
2404 // Handle exit status
2405 switch (ctx
.status
.si_code
) {
2407 DEBUG(jail
->pakfire
, "The child process exited with code %d\n",
2408 ctx
.status
.si_status
);
2411 exit
= ctx
.status
.si_status
;
2415 ERROR(jail
->pakfire
, "The child process was killed\n");
2420 ERROR(jail
->pakfire
, "The child process terminated abnormally\n");
2423 // Log anything else
2425 ERROR(jail
->pakfire
, "Unknown child exit code: %d\n", ctx
.status
.si_code
);
2430 // Destroy the temporary cgroup (if any)
2432 // Read cgroup stats
2433 pakfire_cgroup_stat(ctx
.cgroup
, &ctx
.cgroup_stats
);
2434 pakfire_cgroup_stat_dump(ctx
.cgroup
, &ctx
.cgroup_stats
);
2435 pakfire_cgroup_destroy(ctx
.cgroup
);
2436 pakfire_cgroup_unref(ctx
.cgroup
);
2439 // Close any file descriptors
2442 if (ctx
.pty
.master
.fd
>= 0)
2443 close(ctx
.pty
.master
.fd
);
2444 pakfire_jail_close_pipe(jail
, ctx
.pipes
.log_INFO
);
2445 pakfire_jail_close_pipe(jail
, ctx
.pipes
.log_ERROR
);
2447 pakfire_jail_close_pipe(jail
, ctx
.pipes
.log_DEBUG
);
2448 #endif /* ENABLE_DEBUG */
2449 pakfire_jail_close_pipe(jail
, ctx
.socket
);
2454 PAKFIRE_EXPORT
int pakfire_jail_exec(
2455 struct pakfire_jail
* jail
,
2457 pakfire_jail_communicate_in callback_in
,
2458 pakfire_jail_communicate_out callback_out
,
2459 void* data
, int flags
) {
2460 return __pakfire_jail_exec(jail
, argv
, 0, callback_in
, callback_out
, data
, flags
);
2463 static int pakfire_jail_exec_interactive(
2464 struct pakfire_jail
* jail
, const char* argv
[], int flags
) {
2467 // Setup interactive stuff
2468 r
= pakfire_jail_setup_interactive_env(jail
);
2472 return __pakfire_jail_exec(jail
, argv
, 1, NULL
, NULL
, NULL
, flags
);
2475 int pakfire_jail_exec_script(struct pakfire_jail
* jail
,
2479 pakfire_jail_communicate_in callback_in
,
2480 pakfire_jail_communicate_out callback_out
,
2482 char path
[PATH_MAX
];
2483 const char** argv
= NULL
;
2487 const char* root
= pakfire_get_path(jail
->pakfire
);
2489 // Write the scriptlet to disk
2490 r
= pakfire_path_append(path
, root
, PAKFIRE_TMP_DIR
"/pakfire-script.XXXXXX");
2494 // Create a temporary file
2495 f
= pakfire_mktemp(path
, 0700);
2497 ERROR(jail
->pakfire
, "Could not create temporary file: %m\n");
2501 DEBUG(jail
->pakfire
, "Writing script to %s:\n%.*s\n", path
, (int)size
, script
);
2504 r
= fprintf(f
, "%s", script
);
2506 ERROR(jail
->pakfire
, "Could not write script to file %s: %m\n", path
);
2513 ERROR(jail
->pakfire
, "Could not close script file %s: %m\n", path
);
2519 // Count how many arguments were passed
2520 unsigned int argc
= 1;
2522 for (const char** arg
= args
; *arg
; arg
++)
2526 argv
= calloc(argc
+ 1, sizeof(*argv
));
2528 ERROR(jail
->pakfire
, "Could not allocate argv: %m\n");
2533 argv
[0] = (root
) ? pakfire_path_relpath(root
, path
) : path
;
2536 for (unsigned int i
= 1; i
< argc
; i
++)
2537 argv
[i
] = args
[i
-1];
2540 r
= pakfire_jail_exec(jail
, argv
, callback_in
, callback_out
, data
, 0);
2548 // Remove script from disk
2556 A convenience function that creates a new jail, runs the given command and destroys
2559 int pakfire_jail_run(struct pakfire
* pakfire
, const char* argv
[], int flags
, char** output
) {
2560 struct pakfire_jail
* jail
= NULL
;
2563 // Create a new jail
2564 r
= pakfire_jail_create(&jail
, pakfire
);
2568 // Execute the command
2569 r
= pakfire_jail_exec(jail
, argv
, NULL
, pakfire_jail_capture_stdout
, output
, 0);
2573 pakfire_jail_unref(jail
);
2578 int pakfire_jail_run_script(struct pakfire
* pakfire
,
2579 const char* script
, const size_t length
, const char* argv
[], int flags
) {
2580 struct pakfire_jail
* jail
= NULL
;
2583 // Create a new jail
2584 r
= pakfire_jail_create(&jail
, pakfire
);
2588 // Execute the command
2589 r
= pakfire_jail_exec_script(jail
, script
, length
, argv
, NULL
, NULL
, NULL
);
2593 pakfire_jail_unref(jail
);
2598 int pakfire_jail_shell(struct pakfire_jail
* jail
) {
2601 const char* argv
[] = {
2602 "/bin/bash", "--login", NULL
,
2605 // Execute /bin/bash
2606 r
= pakfire_jail_exec_interactive(jail
, argv
, 0);
2612 // Ignore any return codes from the shell
2616 static int pakfire_jail_run_if_possible(struct pakfire
* pakfire
, const char** argv
) {
2617 char path
[PATH_MAX
];
2620 r
= pakfire_path(pakfire
, path
, "%s", *argv
);
2624 // Check if the file is executable
2625 r
= access(path
, X_OK
);
2627 DEBUG(pakfire
, "%s is not executable. Skipping...\n", *argv
);
2631 return pakfire_jail_run(pakfire
, argv
, 0, NULL
);
2634 int pakfire_jail_ldconfig(struct pakfire
* pakfire
) {
2635 const char* argv
[] = {
2640 return pakfire_jail_run_if_possible(pakfire
, argv
);
2643 int pakfire_jail_run_systemd_tmpfiles(struct pakfire
* pakfire
) {
2644 const char* argv
[] = {
2645 "/usr/bin/systemd-tmpfiles",
2650 return pakfire_jail_run_if_possible(pakfire
, argv
);