return strdup(NOBODY_USER_NAME);
if (uid_is_valid(uid)) {
- long bufsize;
+ _cleanup_free_ struct passwd *pw = NULL;
- bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
- if (bufsize <= 0)
- bufsize = 4096;
-
- for (;;) {
- struct passwd pwbuf, *pw = NULL;
- _cleanup_free_ char *buf = NULL;
-
- buf = malloc(bufsize);
- if (!buf)
- return NULL;
-
- r = getpwuid_r(uid, &pwbuf, buf, (size_t) bufsize, &pw);
- if (r == 0 && pw)
- return strdup(pw->pw_name);
- if (r != ERANGE)
- break;
-
- if (bufsize > LONG_MAX/2) /* overflow check */
- return NULL;
-
- bufsize *= 2;
- }
+ r = getpwuid_malloc(uid, &pw);
+ if (r >= 0)
+ return strdup(pw->pw_name);
}
if (asprintf(&ret, UID_FMT, uid) < 0)
return strdup(NOBODY_GROUP_NAME);
if (gid_is_valid(gid)) {
- long bufsize;
+ _cleanup_free_ struct group *gr = NULL;
- bufsize = sysconf(_SC_GETGR_R_SIZE_MAX);
- if (bufsize <= 0)
- bufsize = 4096;
-
- for (;;) {
- struct group grbuf, *gr = NULL;
- _cleanup_free_ char *buf = NULL;
-
- buf = malloc(bufsize);
- if (!buf)
- return NULL;
-
- r = getgrgid_r(gid, &grbuf, buf, (size_t) bufsize, &gr);
- if (r == 0 && gr)
- return strdup(gr->gr_name);
- if (r != ERANGE)
- break;
-
- if (bufsize > LONG_MAX/2) /* overflow check */
- return NULL;
-
- bufsize *= 2;
- }
+ r = getgrgid_malloc(gid, &gr);
+ if (r >= 0)
+ return strdup(gr->gr_name);
}
if (asprintf(&ret, GID_FMT, gid) < 0)
}
int get_home_dir(char **ret) {
- struct passwd *p;
+ _cleanup_free_ struct passwd *p = NULL;
const char *e;
uid_t u;
+ int r;
assert(ret);
e = "/root";
goto found;
}
-
if (u == UID_NOBODY && synthesize_nobody()) {
e = "/";
goto found;
}
/* Check the database... */
- errno = 0;
- p = getpwuid(u);
- if (!p)
- return errno_or_else(ESRCH);
- e = p->pw_dir;
+ r = getpwuid_malloc(u, &p);
+ if (r < 0)
+ return r;
+ e = p->pw_dir;
if (!path_is_valid(e) || !path_is_absolute(e))
return -EINVAL;
}
int get_shell(char **ret) {
- struct passwd *p;
+ _cleanup_free_ struct passwd *p = NULL;
const char *e;
uid_t u;
+ int r;
assert(ret);
}
/* Check the database... */
- errno = 0;
- p = getpwuid(u);
- if (!p)
- return errno_or_else(ESRCH);
- e = p->pw_shell;
+ r = getpwuid_malloc(u, &p);
+ if (r < 0)
+ return r;
+ e = p->pw_shell;
if (!path_is_valid(e) || !path_is_absolute(e))
return -EINVAL;
return "/home";
}
+
+static size_t getpw_buffer_size(void) {
+ long bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
+ return bufsize <= 0 ? 4096U : (size_t) bufsize;
+}
+
+static bool errno_is_user_doesnt_exist(int error) {
+ /* See getpwnam(3) and getgrnam(3): those codes and others can be returned if the user or group are
+ * not found. */
+ return IN_SET(abs(error), ENOENT, ESRCH, EBADF, EPERM);
+}
+
+int getpwnam_malloc(const char *name, struct passwd **ret) {
+ size_t bufsize = getpw_buffer_size();
+ int r;
+
+ /* A wrapper around getpwnam_r() that allocates the necessary buffer on the heap. The caller must
+ * free() the returned sructured! */
+
+ if (isempty(name))
+ return -EINVAL;
+
+ for (;;) {
+ _cleanup_free_ void *buf = NULL;
+
+ buf = malloc(ALIGN(sizeof(struct passwd)) + bufsize);
+ if (!buf)
+ return -ENOMEM;
+
+ struct passwd *pw = NULL;
+ r = getpwnam_r(name, buf, (char*) buf + ALIGN(sizeof(struct passwd)), (size_t) bufsize, &pw);
+ if (r == 0) {
+ if (pw) {
+ if (ret)
+ *ret = TAKE_PTR(buf);
+ return 0;
+ }
+
+ return -ESRCH;
+ }
+
+ assert(r > 0);
+
+ /* getpwnam() may fail with ENOENT if /etc/passwd is missing. For us that is equivalent to
+ * the name not being defined. */
+ if (errno_is_user_doesnt_exist(r))
+ return -ESRCH;
+ if (r != ERANGE)
+ return -r;
+
+ if (bufsize > SIZE_MAX/2 - ALIGN(sizeof(struct passwd)))
+ return -ENOMEM;
+ bufsize *= 2;
+ }
+}
+
+int getpwuid_malloc(uid_t uid, struct passwd **ret) {
+ size_t bufsize = getpw_buffer_size();
+ int r;
+
+ if (!uid_is_valid(uid))
+ return -EINVAL;
+
+ for (;;) {
+ _cleanup_free_ void *buf = NULL;
+
+ buf = malloc(ALIGN(sizeof(struct passwd)) + bufsize);
+ if (!buf)
+ return -ENOMEM;
+
+ struct passwd *pw = NULL;
+ r = getpwuid_r(uid, buf, (char*) buf + ALIGN(sizeof(struct passwd)), (size_t) bufsize, &pw);
+ if (r == 0) {
+ if (pw) {
+ if (ret)
+ *ret = TAKE_PTR(buf);
+ return 0;
+ }
+
+ return -ESRCH;
+ }
+
+ assert(r > 0);
+
+ if (errno_is_user_doesnt_exist(r))
+ return -ESRCH;
+ if (r != ERANGE)
+ return -r;
+
+ if (bufsize > SIZE_MAX/2 - ALIGN(sizeof(struct passwd)))
+ return -ENOMEM;
+ bufsize *= 2;
+ }
+}
+
+static size_t getgr_buffer_size(void) {
+ long bufsize = sysconf(_SC_GETGR_R_SIZE_MAX);
+ return bufsize <= 0 ? 4096U : (size_t) bufsize;
+}
+
+int getgrnam_malloc(const char *name, struct group **ret) {
+ size_t bufsize = getgr_buffer_size();
+ int r;
+
+ if (isempty(name))
+ return -EINVAL;
+
+ for (;;) {
+ _cleanup_free_ void *buf = NULL;
+
+ buf = malloc(ALIGN(sizeof(struct group)) + bufsize);
+ if (!buf)
+ return -ENOMEM;
+
+ struct group *gr = NULL;
+ r = getgrnam_r(name, buf, (char*) buf + ALIGN(sizeof(struct group)), (size_t) bufsize, &gr);
+ if (r == 0) {
+ if (gr) {
+ if (ret)
+ *ret = TAKE_PTR(buf);
+ return 0;
+ }
+
+ return -ESRCH;
+ }
+
+ assert(r > 0);
+
+ if (errno_is_user_doesnt_exist(r))
+ return -ESRCH;
+ if (r != ERANGE)
+ return -r;
+
+ if (bufsize > SIZE_MAX/2 - ALIGN(sizeof(struct group)))
+ return -ENOMEM;
+ bufsize *= 2;
+ }
+}
+
+int getgrgid_malloc(gid_t gid, struct group **ret) {
+ size_t bufsize = getgr_buffer_size();
+ int r;
+
+ if (!gid_is_valid(gid))
+ return -EINVAL;
+
+ for (;;) {
+ _cleanup_free_ void *buf = NULL;
+
+ buf = malloc(ALIGN(sizeof(struct group)) + bufsize);
+ if (!buf)
+ return -ENOMEM;
+
+ struct group *gr = NULL;
+ r = getgrgid_r(gid, buf, (char*) buf + ALIGN(sizeof(struct group)), (size_t) bufsize, &gr);
+ if (r == 0) {
+ if (gr) {
+ if (ret)
+ *ret = TAKE_PTR(buf);
+ return 0;
+ }
+
+ return -ESRCH;
+ }
+
+ assert(r > 0);
+
+ if (errno_is_user_doesnt_exist(r))
+ return -ESRCH;
+ if (r != ERANGE)
+ return -r;
+
+ if (bufsize > SIZE_MAX/2 - ALIGN(sizeof(struct group)))
+ return -ENOMEM;
+ bufsize *= 2;
+ }
+}
projects / thirdparty / systemd.git / blobdiff