summaryrefslogtreecommitdiffstats
path: root/src/basic/process-util.h
blob: af6cba13ebdd3f6e09422fe71b3ad475b57acf3f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once

#include <errno.h>
#include <sched.h>
#include <signal.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <sys/resource.h>
#include <sys/types.h>

#include "alloc-util.h"
#include "format-util.h"
#include "macro.h"
#include "namespace-util.h"
#include "time-util.h"

#define procfs_file_alloca(pid, field)                                  \
        ({                                                              \
                pid_t _pid_ = (pid);                                    \
                const char *_field_ = (field);                          \
                char *_r_;                                              \
                if (_pid_ == 0) {                                       \
                        _r_ = newa(char, STRLEN("/proc/self/") + strlen(_field_) + 1); \
                        strcpy(stpcpy(_r_, "/proc/self/"), _field_);    \
                } else {                                                \
                        _r_ = newa(char, STRLEN("/proc/") + DECIMAL_STR_MAX(pid_t) + 1 + strlen(_field_) + 1); \
                        sprintf(_r_, "/proc/" PID_FMT "/%s", _pid_, _field_); \
                }                                                       \
                (const char*) _r_;                                      \
        })

typedef enum ProcessCmdlineFlags {
        PROCESS_CMDLINE_COMM_FALLBACK = 1 << 0,
        PROCESS_CMDLINE_USE_LOCALE    = 1 << 1,
        PROCESS_CMDLINE_QUOTE         = 1 << 2,
        PROCESS_CMDLINE_QUOTE_POSIX   = 1 << 3,
} ProcessCmdlineFlags;

int pid_get_comm(pid_t pid, char **ret);
int pidref_get_comm(const PidRef *pid, char **ret);
int pid_get_cmdline(pid_t pid, size_t max_columns, ProcessCmdlineFlags flags, char **ret);
int pidref_get_cmdline(const PidRef *pid, size_t max_columns, ProcessCmdlineFlags flags, char **ret);
int pid_get_cmdline_strv(pid_t pid, ProcessCmdlineFlags flags, char ***ret);
int pidref_get_cmdline_strv(const PidRef *pid, ProcessCmdlineFlags flags, char ***ret);
int get_process_exe(pid_t pid, char **ret);
int pid_get_uid(pid_t pid, uid_t *ret);
int pidref_get_uid(const PidRef *pid, uid_t *ret);
int get_process_gid(pid_t pid, gid_t *ret);
int get_process_capeff(pid_t pid, char **ret);
int get_process_cwd(pid_t pid, char **ret);
int get_process_root(pid_t pid, char **ret);
int get_process_environ(pid_t pid, char **ret);
int get_process_ppid(pid_t pid, pid_t *ret);
int get_process_umask(pid_t pid, mode_t *ret);

int container_get_leader(const char *machine, pid_t *pid);

int namespace_get_leader(pid_t pid, NamespaceType type, pid_t *ret);

int wait_for_terminate(pid_t pid, siginfo_t *status);

typedef enum WaitFlags {
        WAIT_LOG_ABNORMAL             = 1 << 0,
        WAIT_LOG_NON_ZERO_EXIT_STATUS = 1 << 1,

        /* A shortcut for requesting the most complete logging */
        WAIT_LOG = WAIT_LOG_ABNORMAL|WAIT_LOG_NON_ZERO_EXIT_STATUS,
} WaitFlags;

int wait_for_terminate_and_check(const char *name, pid_t pid, WaitFlags flags);
int wait_for_terminate_with_timeout(pid_t pid, usec_t timeout);

void sigkill_wait(pid_t pid);
void sigkill_waitp(pid_t *pid);
void sigterm_wait(pid_t pid);
void sigkill_nowait(pid_t pid);
void sigkill_nowaitp(pid_t *pid);

int kill_and_sigcont(pid_t pid, int sig);

int pid_is_kernel_thread(pid_t pid);
int pidref_is_kernel_thread(const PidRef *pid);

int getenv_for_pid(pid_t pid, const char *field, char **_value);

int pid_is_alive(pid_t pid);
int pidref_is_alive(const PidRef *pidref);
int pid_is_unwaited(pid_t pid);
int pidref_is_unwaited(const PidRef *pidref);
int pid_is_my_child(pid_t pid);
int pidref_is_my_child(const PidRef *pidref);
int pid_from_same_root_fs(pid_t pid);

bool is_main_thread(void);

bool oom_score_adjust_is_valid(int oa);

#ifndef PERSONALITY_INVALID
/* personality(7) documents that 0xffffffffUL is used for querying the
 * current personality, hence let's use that here as error
 * indicator. */
#define PERSONALITY_INVALID 0xffffffffLU
#endif

unsigned long personality_from_string(const char *p);
const char *personality_to_string(unsigned long);

int safe_personality(unsigned long p);
int opinionated_personality(unsigned long *ret);

const char *sigchld_code_to_string(int i) _const_;
int sigchld_code_from_string(const char *s) _pure_;

int sched_policy_to_string_alloc(int i, char **s);
int sched_policy_from_string(const char *s);

static inline pid_t PTR_TO_PID(const void *p) {
        return (pid_t) ((uintptr_t) p);
}

static inline void* PID_TO_PTR(pid_t pid) {
        return (void*) ((uintptr_t) pid);
}

void valgrind_summary_hack(void);

int pid_compare_func(const pid_t *a, const pid_t *b);

static inline bool nice_is_valid(int n) {
        return n >= PRIO_MIN && n < PRIO_MAX;
}

static inline bool sched_policy_is_valid(int i) {
        return IN_SET(i, SCHED_OTHER, SCHED_BATCH, SCHED_IDLE, SCHED_FIFO, SCHED_RR);
}

static inline bool sched_priority_is_valid(int i) {
        return i >= 0 && i <= sched_get_priority_max(SCHED_RR);
}

static inline bool pid_is_valid(pid_t p) {
        return p > 0;
}

pid_t getpid_cached(void);
void reset_cached_pid(void);

int must_be_root(void);

pid_t clone_with_nested_stack(int (*fn)(void *), int flags, void *userdata);

/* 💣 Note that FORK_NEW_USERNS + FORK_NEW_MOUNTNS should not be called in threaded programs, because they
 * cause us to use raw_clone() which does not synchronize the glibc malloc() locks, and thus will cause
 * deadlocks if the parent uses threads and the child does memory allocations. Hence: if the parent is
 * threaded these flags may not be used. These flags cannot be used if the parent uses threads or the child
 * uses malloc(). 💣 */
typedef enum ForkFlags {
        FORK_RESET_SIGNALS      = 1 <<  0, /* Reset all signal handlers and signal mask */
        FORK_CLOSE_ALL_FDS      = 1 <<  1, /* Close all open file descriptors in the child, except for 0,1,2 */
        FORK_DEATHSIG_SIGTERM   = 1 <<  2, /* Set PR_DEATHSIG in the child to SIGTERM */
        FORK_DEATHSIG_SIGINT    = 1 <<  3, /* Set PR_DEATHSIG in the child to SIGINT */
        FORK_DEATHSIG_SIGKILL   = 1 <<  4, /* Set PR_DEATHSIG in the child to SIGKILL */
        FORK_REARRANGE_STDIO    = 1 <<  5, /* Connect 0,1,2 to specified fds or /dev/null */
        FORK_REOPEN_LOG         = 1 <<  6, /* Reopen log connection */
        FORK_LOG                = 1 <<  7, /* Log above LOG_DEBUG log level about failures */
        FORK_WAIT               = 1 <<  8, /* Wait until child exited */
        FORK_NEW_MOUNTNS        = 1 <<  9, /* Run child in its own mount namespace                               💣 DO NOT USE IN THREADED PROGRAMS! 💣 */
        FORK_MOUNTNS_SLAVE      = 1 << 10, /* Make child's mount namespace MS_SLAVE */
        FORK_PRIVATE_TMP        = 1 << 11, /* Mount new /tmp/ in the child (combine with FORK_NEW_MOUNTNS!) */
        FORK_RLIMIT_NOFILE_SAFE = 1 << 12, /* Set RLIMIT_NOFILE soft limit to 1K for select() compat */
        FORK_STDOUT_TO_STDERR   = 1 << 13, /* Make stdout a copy of stderr */
        FORK_FLUSH_STDIO        = 1 << 14, /* fflush() stdout (and stderr) before forking */
        FORK_NEW_USERNS         = 1 << 15, /* Run child in its own user namespace                                💣 DO NOT USE IN THREADED PROGRAMS! 💣 */
        FORK_CLOEXEC_OFF        = 1 << 16, /* In the child: turn off O_CLOEXEC on all fds in except_fds[] */
        FORK_KEEP_NOTIFY_SOCKET = 1 << 17, /* Unless this specified, $NOTIFY_SOCKET will be unset. */
        FORK_DETACH             = 1 << 18, /* Double fork if needed to ensure PID1/subreaper is parent */
} ForkFlags;

int safe_fork_full(
                const char *name,
                const int stdio_fds[3],
                const int except_fds[],
                size_t n_except_fds,
                ForkFlags flags,
                pid_t *ret_pid);

static inline int safe_fork(const char *name, ForkFlags flags, pid_t *ret_pid) {
        return safe_fork_full(name, NULL, NULL, 0, flags, ret_pid);
}

int namespace_fork(const char *outer_name, const char *inner_name, const int except_fds[], size_t n_except_fds, ForkFlags flags, int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd, pid_t *ret_pid);

int set_oom_score_adjust(int value);
int get_oom_score_adjust(int *ret);

/* The highest possibly (theoretic) pid_t value on this architecture. */
#define PID_T_MAX ((pid_t) INT32_MAX)
/* The maximum number of concurrent processes Linux allows on this architecture, as well as the highest valid PID value
 * the kernel will potentially assign. This reflects a value compiled into the kernel (PID_MAX_LIMIT), and sets the
 * upper boundary on what may be written to the /proc/sys/kernel/pid_max sysctl (but do note that the sysctl is off by
 * 1, since PID 0 can never exist and there can hence only be one process less than the limit would suggest). Since
 * these values are documented in proc(5) we feel quite confident that they are stable enough for the near future at
 * least to define them here too. */
#define TASKS_MAX 4194303U

assert_cc(TASKS_MAX <= (unsigned long) PID_T_MAX);

/* Like TAKE_PTR() but for pid_t, resetting them to 0 */
#define TAKE_PID(pid) TAKE_GENERIC(pid, pid_t, 0)

int pidfd_get_pid(int fd, pid_t *ret);
int pidfd_verify_pid(int pidfd, pid_t pid);

int setpriority_closest(int priority);

_noreturn_ void freeze(void);

int get_process_threads(pid_t pid);

int is_reaper_process(void);
int make_reaper_process(bool b);

int posix_spawn_wrapper(const char *path, char *const *argv, char *const *envp, pid_t *ret_pid);

int proc_dir_open(DIR **ret);
int proc_dir_read(DIR *d, pid_t *ret);
int proc_dir_read_pidref(DIR *d, PidRef *ret);