[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"
#include "log.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);

        log_debug("About to execute %s", command->path);

        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 = 1;
        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);

        }

        *p = 0;

        /* 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"
acbb0225	14	#include "log.h"
5cb5a6ff	15
034c6ed7 LP	16	static int close_fds(int except[], unsigned n_except) {
	17	DIR *d;
	18	struct dirent *de;
	19	int r = 0;
	20
	21	/* Modifies the fds array! (sorts it) */
	22
	23	if (!(d = opendir("/proc/self/fd")))
	24	return -errno;
	25
	26	while ((de = readdir(d))) {
	27	int fd;
	28
	29	if (de->d_name[0] == '.')
	30	continue;
	31
	32	if ((r = safe_atoi(de->d_name, &fd)) < 0)
	33	goto finish;
	34
	35	if (fd < 3)
	36	continue;
	37
	38	if (fd == dirfd(d))
	39	continue;
	40
	41	if (except) {
	42	bool found;
	43	unsigned i;
	44
	45	found = false;
	46	for (i = 0; i < n_except; i++)
	47	if (except[i] == fd) {
	48	found = true;
	49	break;
	50	}
	51
	52	if (found)
	53	continue;
	54	}
	55
	56	if ((r = close_nointr(fd)) < 0)
	57	goto finish;
	58	}
	59
	60	finish:
	61	closedir(d);
	62	return r;
	63	}
	64
	65	static int shift_fds(int fds[], unsigned n_fds) {
	66	int start, restart_from;
	67
	68	if (n_fds <= 0)
	69	return 0;
	70
	71	assert(fds);
	72
	73	start = 0;
	74	for (;;) {
	75	int i;
	76
	77	restart_from = -1;
	78
	79	for (i = start; i < (int) n_fds; i++) {
80	int nfd;
81
82	/* Already at right index? */
83	if (fds[i] == i+3)
84	continue;
85
86	if ((nfd = fcntl(fds[i], F_DUPFD, i+3)) < 0)
87	return -errno;
88
89	assert_se(close_nointr(fds[i]));
90	fds[i] = nfd;
91
92	/* Hmm, the fd we wanted isn't free? Then
93	* let's remember that and try again from here*/
94	if (nfd != i+3 && restart_from < 0)
95	restart_from = i;
96	}
97
98	if (restart_from < 0)
99	break;
100
101	start = restart_from;
102	}
103
104	return 0;
105	}
106
107	int exec_spawn(const ExecCommand command, const ExecContext context, int fds, unsigned n_fds, pid_t ret) {
108	pid_t pid;
109
5cb5a6ff LP	110	assert(command);
	111	assert(context);
	112	assert(ret);
034c6ed7 LP	113	assert(fds \|\| n_fds <= 0);
034c6ed7 LP	114
acbb0225 LP	115	log_debug("About to execute %s", command->path);
acbb0225 LP	116
034c6ed7 LP	117	if ((pid = fork()) < 0)
	118	return -errno;
	119
	120	if (pid == 0) {
	121	char e, f = NULL;
	122	int i, r;
	123	char t[16];
	124	/* child */
5cb5a6ff	125
034c6ed7 LP	126	umask(context->umask);
	127
	128	if (chdir(context->directory ? context->directory : "/") < 0) {
	129	r = EXIT_CHDIR;
	130	goto fail;
	131	}
	132
	133	snprintf(t, sizeof(t), "%i", context->oom_adjust);
	134	char_array_0(t);
	135
	136	if (write_one_line_file("/proc/self/oom_adj", t) < 0) {
	137	r = EXIT_OOM_ADJUST;
	138	goto fail;
	139	}
	140
	141	if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {
	142	r = EXIT_NICE;
	143	goto fail;
	144	}
	145
	146	if (close_fds(fds, n_fds) < 0 \|\|
	147	shift_fds(fds, n_fds) < 0) {
	148	r = EXIT_FDS;
	149	goto fail;
	150	}
	151
	152	for (i = 0; i < RLIMIT_NLIMITS; i++) {
	153	if (!context->rlimit[i])
	154	continue;
	155
	156	if (setrlimit(i, context->rlimit[i]) < 0) {
	157	r = EXIT_LIMITS;
	158	goto fail;
	159	}
	160	}
	161
	162	if (n_fds > 0) {
	163	char a[64], b[64];
	164	char *listen_env[3] = {
	165	a,
	166	b,
	167	NULL
	168	};
	169
	170	snprintf(a, sizeof(a), "LISTEN_PID=%llu", (unsigned long long) getpid());
	171	snprintf(b, sizeof(b), "LISTEN_FDS=%u", n_fds);
	172
	173	a[sizeof(a)-1] = 0;
	174	b[sizeof(b)-1] = 0;
	175
	176	if (context->environment) {
	177	if (!(f = strv_merge(listen_env, context->environment))) {
	178	r = EXIT_MEMORY;
	179	goto fail;
	180	}
	181	e = f;
	182	} else
	183	e = listen_env;
	184
	185	} else
	186	e = context->environment;
	187
	188	execve(command->path, command->argv, e);
	189	r = EXIT_EXEC;
190
191	fail:
192	strv_free(f);
193	_exit(r);
194	}
195
196	*ret = pid;
5cb5a6ff LP	197	return 0;
	198	}
	199
034c6ed7 LP	200	void exec_context_init(ExecContext *c) {
	201	assert(c);
	202
	203	c->umask = 0002;
	204	cap_clear(c->capabilities);
	205	c->oom_adjust = 0;
	206	c->nice = 0;
	207	}
	208
	209	void exec_context_done(ExecContext *c) {
5cb5a6ff LP	210	unsigned l;
	211
	212	assert(c);
	213
	214	strv_free(c->environment);
034c6ed7	215	c->environment = NULL;
5cb5a6ff	216
034c6ed7	217	for (l = 0; l < ELEMENTSOF(c->rlimit); l++) {
5cb5a6ff	218	free(c->rlimit[l]);
034c6ed7 LP	219	c->rlimit[l] = NULL;
	220	}
	221
	222	free(c->directory);
	223	c->directory = NULL;
5cb5a6ff	224
5cb5a6ff	225	free(c->user);
034c6ed7 LP	226	c->user = NULL;
034c6ed7 LP	227
5cb5a6ff	228	free(c->group);
034c6ed7 LP	229	c->group = NULL;
	230
	231	strv_free(c->supplementary_groups);
	232	c->supplementary_groups = NULL;
5cb5a6ff LP	233	}
	234
	235	void exec_command_free_list(ExecCommand *c) {
	236	ExecCommand *i;
	237
	238	while ((i = c)) {
034c6ed7	239	LIST_REMOVE(ExecCommand, command, c, i);
5cb5a6ff LP	240
5cb5a6ff LP	241	free(i->path);
44d8db9e	242	strv_free(i->argv);
5cb5a6ff LP	243	free(i);
	244	}
	245	}
	246
034c6ed7 LP	247	void exec_command_free_array(ExecCommand **c, unsigned n) {
	248	unsigned i;
	249
	250	for (i = 0; i < n; i++) {
	251	exec_command_free_list(c[i]);
	252	c[i] = NULL;
	253	}
	254	}
	255
5cb5a6ff LP	256	void exec_context_dump(ExecContext c, FILE f, const char *prefix) {
	257	assert(c);
	258	assert(f);
	259
	260	if (!prefix)
	261	prefix = "";
	262
	263	fprintf(f,
	264	"%sUmask: %04o\n"
034c6ed7 LP	265	"%sDirectory: %s\n"
	266	"%sNice: %i\n"
	267	"%sOOMAdjust: %i\n",
5cb5a6ff	268	prefix, c->umask,
034c6ed7 LP	269	prefix, c->directory ? c->directory : "/",
	270	prefix, c->nice,
	271	prefix, c->oom_adjust);
5cb5a6ff LP	272	}
5cb5a6ff LP	273
034c6ed7 LP	274	void exec_status_fill(ExecStatus *s, pid_t pid, int code, int status) {
034c6ed7 LP	275	assert(s);
5cb5a6ff	276
034c6ed7 LP	277	s->pid = pid;
	278	s->code = code;
	279	s->status = status;
	280	s->timestamp = now(CLOCK_REALTIME);
5cb5a6ff	281	}
44d8db9e LP	282
	283	char exec_command_line(ExecCommand c) {
	284	size_t k;
	285	char n, p, **a;
	286	bool first = true;
	287
	288	assert(c);
	289	assert(c->argv);
	290
9164977d	291	k = 1;
44d8db9e LP	292	STRV_FOREACH(a, c->argv)
	293	k += strlen(*a)+3;
	294
	295	if (!(n = new(char, k)))
	296	return NULL;
	297
	298	p = n;
	299	STRV_FOREACH(a, c->argv) {
	300
	301	if (!first)
	302	*(p++) = ' ';
	303	else
	304	first = false;
	305
	306	if (strpbrk(*a, WHITESPACE)) {
	307	*(p++) = '\'';
	308	p = stpcpy(p, *a);
	309	*(p++) = '\'';
	310	} else
	311	p = stpcpy(p, *a);
	312
	313	}
	314
9164977d LP	315	*p = 0;
9164977d LP	316
44d8db9e LP	317	/* FIXME: this doesn't really handle arguments that have
	318	* spaces and ticks in them */
	319
	320	return n;
	321	}
	322
	323	void exec_command_dump(ExecCommand c, FILE f, const char *prefix) {
	324	char *cmd;
	325
	326	assert(c);
	327	assert(f);
	328
	329	if (!prefix)
	330	prefix = "";
	331
	332	cmd = exec_command_line(c);
	333
	334	fprintf(f,
	335	"%sCommand Line: %s\n",
	336	prefix, cmd ? cmd : strerror(ENOMEM));
	337
	338	free(cmd);
	339	}
	340
	341	void exec_command_dump_list(ExecCommand c, FILE f, const char *prefix) {
	342	assert(f);
	343
	344	if (!prefix)
	345	prefix = "";
	346
	347	LIST_FOREACH(command, c, c)
	348	exec_command_dump(c, f, prefix);
	349	}