[people/ms/systemd.git] / execute.c

/*-*- Mode: C; c-basic-offset: 8 -*-*/

#include <assert.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>

#include "execute.h"
#include "strv.h"
#include "macro.h"
#include "util.h"

static int close_fds(int except[], unsigned n_except) {
        DIR *d;
        struct dirent *de;
        int r = 0;

        /* Modifies the fds array! (sorts it) */

        if (!(d = opendir("/proc/self/fd")))
                return -errno;

        while ((de = readdir(d))) {
                int fd;

                if (de->d_name[0] == '.')
                        continue;

                if ((r = safe_atoi(de->d_name, &fd)) < 0)
                        goto finish;

                if (fd < 3)
                        continue;

                if (fd == dirfd(d))
                        continue;

                if (except) {
                        bool found;
                        unsigned i;

                        found = false;
                        for (i = 0; i < n_except; i++)
                                if (except[i] == fd) {
                                        found = true;
                                        break;
                                }

                        if (found)
                                continue;
                }

                if ((r = close_nointr(fd)) < 0)
                        goto finish;
        }

finish:
        closedir(d);
        return r;
}

static int shift_fds(int fds[], unsigned n_fds) {
        int start, restart_from;

        if (n_fds <= 0)
                return 0;

        assert(fds);

        start = 0;
        for (;;) {
                int i;

                restart_from = -1;

                for (i = start; i < (int) n_fds; i++) {
                        int nfd;

                        /* Already at right index? */
                        if (fds[i] == i+3)
                                continue;

                        if ((nfd = fcntl(fds[i], F_DUPFD, i+3)) < 0)
                                return -errno;

                        assert_se(close_nointr(fds[i]));
                        fds[i] = nfd;

                        /* Hmm, the fd we wanted isn't free? Then
                         * let's remember that and try again from here*/
                        if (nfd != i+3 && restart_from < 0)
                                restart_from = i;
                }

                if (restart_from < 0)
                        break;

                start = restart_from;
        }

        return 0;
}

int exec_spawn(const ExecCommand *command, const ExecContext *context, int *fds, unsigned n_fds, pid_t *ret) {
        pid_t pid;

        assert(command);
        assert(context);
        assert(ret);
        assert(fds || n_fds <= 0);

        if ((pid = fork()) < 0)
                return -errno;

        if (pid == 0) {
                char **e, **f = NULL;
                int i, r;
                char t[16];
                /* child */

                umask(context->umask);

                if (chdir(context->directory ? context->directory : "/") < 0) {
                        r = EXIT_CHDIR;
                        goto fail;
                }

                snprintf(t, sizeof(t), "%i", context->oom_adjust);
                char_array_0(t);

                if (write_one_line_file("/proc/self/oom_adj", t) < 0) {
                        r = EXIT_OOM_ADJUST;
                        goto fail;
                }

                if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {
                        r = EXIT_NICE;
                        goto fail;
                }

                if (close_fds(fds, n_fds) < 0 ||
                    shift_fds(fds, n_fds) < 0) {
                        r = EXIT_FDS;
                        goto fail;
                }

                for (i = 0; i < RLIMIT_NLIMITS; i++) {
                        if (!context->rlimit[i])
                                continue;

                        if (setrlimit(i, context->rlimit[i]) < 0) {
                                r = EXIT_LIMITS;
                                goto fail;
                        }
                }

                if (n_fds > 0) {
                        char a[64], b[64];
                        char *listen_env[3] = {
                                a,
                                b,
                                NULL
                        };

                        snprintf(a, sizeof(a), "LISTEN_PID=%llu", (unsigned long long) getpid());
                        snprintf(b, sizeof(b), "LISTEN_FDS=%u", n_fds);

                        a[sizeof(a)-1] = 0;
                        b[sizeof(b)-1] = 0;

                        if (context->environment) {
                                if (!(f = strv_merge(listen_env, context->environment))) {
                                        r = EXIT_MEMORY;
                                        goto fail;
                                }
                                e = f;
                        } else
                                e = listen_env;

                } else
                        e = context->environment;

                execve(command->path, command->argv, e);
                r = EXIT_EXEC;

        fail:
                strv_free(f);
                _exit(r);
        }

        *ret = pid;
        return 0;
}

void exec_context_init(ExecContext *c) {
        assert(c);

        c->umask = 0002;
        cap_clear(c->capabilities);
        c->oom_adjust = 0;
        c->nice = 0;
}

void exec_context_done(ExecContext *c) {
        unsigned l;

        assert(c);

        strv_free(c->environment);
        c->environment = NULL;

        for (l = 0; l < ELEMENTSOF(c->rlimit); l++) {
                free(c->rlimit[l]);
                c->rlimit[l] = NULL;
        }

        free(c->directory);
        c->directory = NULL;

        free(c->user);
        c->user = NULL;

        free(c->group);
        c->group = NULL;

        strv_free(c->supplementary_groups);
        c->supplementary_groups = NULL;
}

void exec_command_free_list(ExecCommand *c) {
        ExecCommand *i;

        while ((i = c)) {
                LIST_REMOVE(ExecCommand, command, c, i);

                free(i->path);
                strv_free(i->argv);
                free(i);
        }
}

void exec_command_free_array(ExecCommand **c, unsigned n) {
        unsigned i;

        for (i = 0; i < n; i++) {
                exec_command_free_list(c[i]);
                c[i] = NULL;
        }
}


void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
        assert(c);
        assert(f);

        if (!prefix)
                prefix = "";

        fprintf(f,
                "%sUmask: %04o\n"
                "%sDirectory: %s\n"
                "%sNice: %i\n"
                "%sOOMAdjust: %i\n",
                prefix, c->umask,
                prefix, c->directory ? c->directory : "/",
                prefix, c->nice,
                prefix, c->oom_adjust);
}

void exec_status_fill(ExecStatus *s, pid_t pid, int code, int status) {
        assert(s);

        s->pid = pid;
        s->code = code;
        s->status = status;
        s->timestamp = now(CLOCK_REALTIME);
}

char *exec_command_line(ExecCommand *c) {
        size_t k;
        char *n, *p, **a;
        bool first = true;

        assert(c);
        assert(c->argv);

        k = 0;
        STRV_FOREACH(a, c->argv)
                k += strlen(*a)+3;

        if (!(n = new(char, k)))
                return NULL;

        p = n;
        STRV_FOREACH(a, c->argv) {

                if (!first)
                        *(p++) = ' ';
                else
                        first = false;

                if (strpbrk(*a, WHITESPACE)) {
                        *(p++) = '\'';
                        p = stpcpy(p, *a);
                        *(p++) = '\'';
                } else
                        p = stpcpy(p, *a);

        }

        /* FIXME: this doesn't really handle arguments that have
         * spaces and ticks in them */

        return n;
}

void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) {
        char *cmd;

        assert(c);
        assert(f);

        if (!prefix)
                prefix = "";

        cmd = exec_command_line(c);

        fprintf(f,
                "%sCommand Line: %s\n",
                prefix, cmd ? cmd : strerror(ENOMEM));

        free(cmd);
}

void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) {
        assert(f);

        if (!prefix)
                prefix = "";

        LIST_FOREACH(command, c, c)
                exec_command_dump(c, f, prefix);
}
Commit	Line	Data
5cb5a6ff LP	1	/-- Mode: C; c-basic-offset: 8 --/
	2
	3	#include <assert.h>
034c6ed7 LP	4	#include <dirent.h>
	5	#include <errno.h>
	6	#include <fcntl.h>
	7	#include <unistd.h>
44d8db9e	8	#include <string.h>
5cb5a6ff LP	9
	10	#include "execute.h"
	11	#include "strv.h"
	12	#include "macro.h"
	13	#include "util.h"
	14
034c6ed7 LP	15	static int close_fds(int except[], unsigned n_except) {
	16	DIR *d;
	17	struct dirent *de;
	18	int r = 0;
	19
	20	/* Modifies the fds array! (sorts it) */
	21
	22	if (!(d = opendir("/proc/self/fd")))
	23	return -errno;
	24
	25	while ((de = readdir(d))) {
	26	int fd;
	27
	28	if (de->d_name[0] == '.')
	29	continue;
	30
	31	if ((r = safe_atoi(de->d_name, &fd)) < 0)
	32	goto finish;
	33
	34	if (fd < 3)
	35	continue;
	36
	37	if (fd == dirfd(d))
	38	continue;
	39
	40	if (except) {
	41	bool found;
	42	unsigned i;
	43
	44	found = false;
	45	for (i = 0; i < n_except; i++)
	46	if (except[i] == fd) {
	47	found = true;
	48	break;
	49	}
	50
	51	if (found)
	52	continue;
	53	}
	54
	55	if ((r = close_nointr(fd)) < 0)
	56	goto finish;
	57	}
	58
	59	finish:
	60	closedir(d);
	61	return r;
	62	}
	63
	64	static int shift_fds(int fds[], unsigned n_fds) {
	65	int start, restart_from;
	66
	67	if (n_fds <= 0)
	68	return 0;
	69
	70	assert(fds);
	71
	72	start = 0;
	73	for (;;) {
	74	int i;
	75
	76	restart_from = -1;
	77
	78	for (i = start; i < (int) n_fds; i++) {
79	int nfd;
80
81	/* Already at right index? */
82	if (fds[i] == i+3)
83	continue;
84
85	if ((nfd = fcntl(fds[i], F_DUPFD, i+3)) < 0)
86	return -errno;
87
88	assert_se(close_nointr(fds[i]));
89	fds[i] = nfd;
90
91	/* Hmm, the fd we wanted isn't free? Then
92	* let's remember that and try again from here*/
93	if (nfd != i+3 && restart_from < 0)
94	restart_from = i;
95	}
96
97	if (restart_from < 0)
98	break;
99
100	start = restart_from;
101	}
102
103	return 0;
104	}
105
106	int exec_spawn(const ExecCommand command, const ExecContext context, int fds, unsigned n_fds, pid_t ret) {
107	pid_t pid;
108
5cb5a6ff LP	109	assert(command);
	110	assert(context);
	111	assert(ret);
034c6ed7 LP	112	assert(fds \|\| n_fds <= 0);
	113
	114	if ((pid = fork()) < 0)
	115	return -errno;
	116
	117	if (pid == 0) {
	118	char e, f = NULL;
	119	int i, r;
	120	char t[16];
	121	/* child */
5cb5a6ff	122
034c6ed7 LP	123	umask(context->umask);
	124
	125	if (chdir(context->directory ? context->directory : "/") < 0) {
	126	r = EXIT_CHDIR;
	127	goto fail;
	128	}
	129
	130	snprintf(t, sizeof(t), "%i", context->oom_adjust);
	131	char_array_0(t);
	132
	133	if (write_one_line_file("/proc/self/oom_adj", t) < 0) {
	134	r = EXIT_OOM_ADJUST;
	135	goto fail;
	136	}
	137
	138	if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {
	139	r = EXIT_NICE;
	140	goto fail;
	141	}
	142
	143	if (close_fds(fds, n_fds) < 0 \|\|
	144	shift_fds(fds, n_fds) < 0) {
	145	r = EXIT_FDS;
	146	goto fail;
	147	}
	148
	149	for (i = 0; i < RLIMIT_NLIMITS; i++) {
	150	if (!context->rlimit[i])
	151	continue;
	152
	153	if (setrlimit(i, context->rlimit[i]) < 0) {
	154	r = EXIT_LIMITS;
	155	goto fail;
	156	}
	157	}
	158
	159	if (n_fds > 0) {
	160	char a[64], b[64];
	161	char *listen_env[3] = {
	162	a,
	163	b,
	164	NULL
	165	};
	166
	167	snprintf(a, sizeof(a), "LISTEN_PID=%llu", (unsigned long long) getpid());
	168	snprintf(b, sizeof(b), "LISTEN_FDS=%u", n_fds);
	169
	170	a[sizeof(a)-1] = 0;
	171	b[sizeof(b)-1] = 0;
	172
	173	if (context->environment) {
	174	if (!(f = strv_merge(listen_env, context->environment))) {
	175	r = EXIT_MEMORY;
	176	goto fail;
	177	}
	178	e = f;
	179	} else
	180	e = listen_env;
	181
	182	} else
	183	e = context->environment;
	184
	185	execve(command->path, command->argv, e);
	186	r = EXIT_EXEC;
187
188	fail:
189	strv_free(f);
190	_exit(r);
191	}
192
193	*ret = pid;
5cb5a6ff LP	194	return 0;
	195	}
	196
034c6ed7 LP	197	void exec_context_init(ExecContext *c) {
	198	assert(c);
	199
	200	c->umask = 0002;
	201	cap_clear(c->capabilities);
	202	c->oom_adjust = 0;
	203	c->nice = 0;
	204	}
	205
	206	void exec_context_done(ExecContext *c) {
5cb5a6ff LP	207	unsigned l;
	208
	209	assert(c);
	210
	211	strv_free(c->environment);
034c6ed7	212	c->environment = NULL;
5cb5a6ff	213
034c6ed7	214	for (l = 0; l < ELEMENTSOF(c->rlimit); l++) {
5cb5a6ff	215	free(c->rlimit[l]);
034c6ed7 LP	216	c->rlimit[l] = NULL;
	217	}
	218
	219	free(c->directory);
	220	c->directory = NULL;
5cb5a6ff	221
5cb5a6ff	222	free(c->user);
034c6ed7 LP	223	c->user = NULL;
034c6ed7 LP	224
5cb5a6ff	225	free(c->group);
034c6ed7 LP	226	c->group = NULL;
	227
	228	strv_free(c->supplementary_groups);
	229	c->supplementary_groups = NULL;
5cb5a6ff LP	230	}
	231
	232	void exec_command_free_list(ExecCommand *c) {
	233	ExecCommand *i;
	234
	235	while ((i = c)) {
034c6ed7	236	LIST_REMOVE(ExecCommand, command, c, i);
5cb5a6ff LP	237
5cb5a6ff LP	238	free(i->path);
44d8db9e	239	strv_free(i->argv);
5cb5a6ff LP	240	free(i);
	241	}
	242	}
	243
034c6ed7 LP	244	void exec_command_free_array(ExecCommand **c, unsigned n) {
	245	unsigned i;
	246
	247	for (i = 0; i < n; i++) {
	248	exec_command_free_list(c[i]);
	249	c[i] = NULL;
	250	}
	251	}
	252
	253
5cb5a6ff LP	254	void exec_context_dump(ExecContext c, FILE f, const char *prefix) {
	255	assert(c);
	256	assert(f);
	257
	258	if (!prefix)
	259	prefix = "";
	260
	261	fprintf(f,
	262	"%sUmask: %04o\n"
034c6ed7 LP	263	"%sDirectory: %s\n"
	264	"%sNice: %i\n"
	265	"%sOOMAdjust: %i\n",
5cb5a6ff	266	prefix, c->umask,
034c6ed7 LP	267	prefix, c->directory ? c->directory : "/",
	268	prefix, c->nice,
	269	prefix, c->oom_adjust);
5cb5a6ff LP	270	}
5cb5a6ff LP	271
034c6ed7 LP	272	void exec_status_fill(ExecStatus *s, pid_t pid, int code, int status) {
034c6ed7 LP	273	assert(s);
5cb5a6ff	274
034c6ed7 LP	275	s->pid = pid;
	276	s->code = code;
	277	s->status = status;
	278	s->timestamp = now(CLOCK_REALTIME);
5cb5a6ff	279	}
44d8db9e LP	280
	281	char exec_command_line(ExecCommand c) {
	282	size_t k;
	283	char n, p, **a;
	284	bool first = true;
	285
	286	assert(c);
	287	assert(c->argv);
	288
	289	k = 0;
	290	STRV_FOREACH(a, c->argv)
	291	k += strlen(*a)+3;
	292
	293	if (!(n = new(char, k)))
	294	return NULL;
	295
	296	p = n;
	297	STRV_FOREACH(a, c->argv) {
	298
	299	if (!first)
	300	*(p++) = ' ';
	301	else
	302	first = false;
	303
	304	if (strpbrk(*a, WHITESPACE)) {
	305	*(p++) = '\'';
	306	p = stpcpy(p, *a);
	307	*(p++) = '\'';
	308	} else
	309	p = stpcpy(p, *a);
	310
	311	}
	312
	313	/* FIXME: this doesn't really handle arguments that have
	314	* spaces and ticks in them */
	315
	316	return n;
	317	}
	318
	319	void exec_command_dump(ExecCommand c, FILE f, const char *prefix) {
	320	char *cmd;
	321
	322	assert(c);
	323	assert(f);
	324
	325	if (!prefix)
	326	prefix = "";
	327
	328	cmd = exec_command_line(c);
	329
	330	fprintf(f,
	331	"%sCommand Line: %s\n",
	332	prefix, cmd ? cmd : strerror(ENOMEM));
	333
	334	free(cmd);
	335	}
	336
	337	void exec_command_dump_list(ExecCommand c, FILE f, const char *prefix) {
	338	assert(f);
	339
	340	if (!prefix)
	341	prefix = "";
	342
	343	LIST_FOREACH(command, c, c)
344	exec_command_dump(c, f, prefix);
345	}