[thirdparty/util-linux.git] / lib / pwdutils.c

#include <stdlib.h>

#include "c.h"
#include "pwdutils.h"
#include "xalloc.h"

/* Returns allocated passwd and allocated pwdbuf to store passwd strings
 * fields. In case of error returns NULL and set errno, for unknown user set
 * errno to EINVAL
 */
struct passwd *xgetpwnam(const char *username, char **pwdbuf)
{
	struct passwd *pwd = NULL, *res = NULL;
	int rc;

	if (!pwdbuf || !username)
		return NULL;

	*pwdbuf = xmalloc(UL_GETPW_BUFSIZ);
	pwd = xcalloc(1, sizeof(struct passwd));

	errno = 0;
	rc = getpwnam_r(username, pwd, *pwdbuf, UL_GETPW_BUFSIZ, &res);
	if (rc != 0) {
		errno = rc;
		goto failed;
	}
	if (!res) {
		errno = EINVAL;
		goto failed;
	}
	return pwd;
failed:
	free(pwd);
	free(*pwdbuf);
	return NULL;
}

struct passwd *xgetpwuid(uid_t uid, char **pwdbuf)
{
	struct passwd *pwd = NULL, *res = NULL;
	int rc;

	if (!pwdbuf)
		return NULL;

	*pwdbuf = xmalloc(UL_GETPW_BUFSIZ);
	pwd = xcalloc(1, sizeof(struct passwd));

	errno = 0;
	rc = getpwuid_r(uid, pwd, *pwdbuf, UL_GETPW_BUFSIZ, &res);
	if (rc != 0) {
		errno = rc;
		goto failed;
	}
	if (!res) {
		errno = EINVAL;
		goto failed;
	}
	return pwd;
failed:
	free(pwd);
	free(*pwdbuf);
	return NULL;
}

char *xgetlogin(void)
{
	struct passwd *pw = NULL;
	uid_t ruid;
	char *user;

	user = getlogin();
	if (user)
		return xstrdup(user);

	/* GNU Hurd implementation has an extension where a process can exist in a
	 * non-conforming environment, and thus be outside the realms of POSIX
	 * process identifiers; on this platform, getuid() fails with a status of
	 * (uid_t)(-1) and sets errno if a program is run from a non-conforming
	 * environment.
	 *
	 * http://austingroupbugs.net/view.php?id=511
	 */
	errno = 0;
	ruid = getuid();

	if (errno == 0)
		pw = getpwuid(ruid);
	if (pw && pw->pw_name && *pw->pw_name)
		return xstrdup(pw->pw_name);

	return NULL;
}

#ifdef TEST_PROGRAM
int main(int argc, char *argv[])
{
	char *buf = NULL;
	struct passwd *pwd = NULL;

	if (argc != 2) {
		fprintf(stderr, "usage: %s <username>\n", argv[0]);
		return EXIT_FAILURE;
	}

	pwd = xgetpwnam(argv[1], &buf);
	if (!pwd)
		err(EXIT_FAILURE, "failed to get %s pwd entry", argv[1]);

	printf("Username: %s\n", pwd->pw_name);
	printf("UID:      %d\n", pwd->pw_uid);
	printf("HOME:     %s\n", pwd->pw_dir);
	printf("GECO:     %s\n", pwd->pw_gecos);

	free(pwd);
	free(buf);

	printf("Current:  %s\n", (buf = xgetlogin()));
	free(buf);

	return EXIT_SUCCESS;
}
#endif /* TEST_PROGRAM */
Commit	Line	Data
4f5f35fc KZ	1	#include <stdlib.h>
	2
	3	#include "c.h"
	4	#include "pwdutils.h"
	5	#include "xalloc.h"
	6
	7	/* Returns allocated passwd and allocated pwdbuf to store passwd strings
	8	* fields. In case of error returns NULL and set errno, for unknown user set
	9	* errno to EINVAL
	10	*/
	11	struct passwd xgetpwnam(const char username, char **pwdbuf)
	12	{
	13	struct passwd pwd = NULL, res = NULL;
	14	int rc;
	15
	16	if (!pwdbuf \|\| !username)
	17	return NULL;
	18
	19	*pwdbuf = xmalloc(UL_GETPW_BUFSIZ);
	20	pwd = xcalloc(1, sizeof(struct passwd));
	21
	22	errno = 0;
	23	rc = getpwnam_r(username, pwd, *pwdbuf, UL_GETPW_BUFSIZ, &res);
	24	if (rc != 0) {
	25	errno = rc;
	26	goto failed;
	27	}
	28	if (!res) {
	29	errno = EINVAL;
	30	goto failed;
	31	}
	32	return pwd;
	33	failed:
	34	free(pwd);
	35	free(*pwdbuf);
	36	return NULL;
	37	}
	38
cd083615 QR	39	struct passwd xgetpwuid(uid_t uid, char *pwdbuf)
	40	{
	41	struct passwd pwd = NULL, res = NULL;
	42	int rc;
	43
	44	if (!pwdbuf)
	45	return NULL;
	46
	47	*pwdbuf = xmalloc(UL_GETPW_BUFSIZ);
	48	pwd = xcalloc(1, sizeof(struct passwd));
	49
	50	errno = 0;
	51	rc = getpwuid_r(uid, pwd, *pwdbuf, UL_GETPW_BUFSIZ, &res);
	52	if (rc != 0) {
	53	errno = rc;
	54	goto failed;
	55	}
	56	if (!res) {
	57	errno = EINVAL;
	58	goto failed;
	59	}
	60	return pwd;
	61	failed:
	62	free(pwd);
	63	free(*pwdbuf);
	64	return NULL;
	65	}
	66
1742c8d8 KZ	67	char *xgetlogin(void)
	68	{
	69	struct passwd *pw = NULL;
	70	uid_t ruid;
	71	char *user;
	72
	73	user = getlogin();
	74	if (user)
	75	return xstrdup(user);
	76
	77	/* GNU Hurd implementation has an extension where a process can exist in a
	78	* non-conforming environment, and thus be outside the realms of POSIX
	79	* process identifiers; on this platform, getuid() fails with a status of
	80	* (uid_t)(-1) and sets errno if a program is run from a non-conforming
	81	* environment.
	82	*
	83	* http://austingroupbugs.net/view.php?id=511
	84	*/
	85	errno = 0;
	86	ruid = getuid();
	87
	88	if (errno == 0)
	89	pw = getpwuid(ruid);
	90	if (pw && pw->pw_name && *pw->pw_name)
	91	return xstrdup(pw->pw_name);
	92
	93	return NULL;
	94	}
4f5f35fc KZ	95
	96	#ifdef TEST_PROGRAM
	97	int main(int argc, char *argv[])
	98	{
1742c8d8	99	char *buf = NULL;
4f5f35fc KZ	100	struct passwd *pwd = NULL;
	101
	102	if (argc != 2) {
	103	fprintf(stderr, "usage: %s <username>\n", argv[0]);
	104	return EXIT_FAILURE;
	105	}
	106
1742c8d8	107	pwd = xgetpwnam(argv[1], &buf);
4f5f35fc KZ	108	if (!pwd)
	109	err(EXIT_FAILURE, "failed to get %s pwd entry", argv[1]);
	110
	111	printf("Username: %s\n", pwd->pw_name);
	112	printf("UID: %d\n", pwd->pw_uid);
	113	printf("HOME: %s\n", pwd->pw_dir);
	114	printf("GECO: %s\n", pwd->pw_gecos);
	115
	116	free(pwd);
1742c8d8 KZ	117	free(buf);
	118
	119	printf("Current: %s\n", (buf = xgetlogin()));
	120	free(buf);
	121
4f5f35fc KZ	122	return EXIT_SUCCESS;
	123	}
	124	#endif /* TEST_PROGRAM */