/* Specification. */
#include "userspec.h"
-#include <alloca.h>
-
#include <stdbool.h>
#include <stdio.h>
#include <sys/types.h>
# define MAXGID GID_T_MAX
#endif
-/* Perform the equivalent of the statement `dest = strdup (src);',
- but obtaining storage via alloca instead of from the heap. */
-
-#define V_STRDUP(dest, src) \
- do \
- { \
- size_t size = strlen (src) + 1; \
- (dest) = (char *) alloca (size); \
- memcpy (dest, src, size); \
- } \
- while (0)
-
/* ISDIGIT differs from isdigit, as follows:
- Its arg may be any int or unsigned int; it need not be an unsigned char.
- It's guaranteed to evaluate its argument exactly once.
}
#endif
-/* Extract from NAME, which has the form "[user][:.][group]",
- a USERNAME, UID U, GROUPNAME, and GID G.
- Either user or group, or both, must be present.
- If the group is omitted but the ":" separator is given,
- use the given user's login group.
- If SPEC_ARG contains a `:', then use that as the separator, ignoring
- any `.'s. If there is no `:', but there is a `.', then first look
- up the entire SPEC_ARG as a login name. If that look-up fails, then
- try again interpreting the `.' as a separator.
-
- USERNAME and GROUPNAME will be in newly malloc'd memory.
- Either one might be NULL instead, indicating that it was not
- given and the corresponding numeric ID was left unchanged.
-
- Return NULL if successful, a static error message string if not. */
-
-const char *
-parse_user_spec (const char *spec_arg, uid_t *uid, gid_t *gid,
- char **username_arg, char **groupname_arg)
+static char const *
+parse_with_separator (char const *spec, char const *separator,
+ uid_t *uid, gid_t *gid,
+ char **username, char **groupname)
{
static const char *E_invalid_user = N_("invalid user");
static const char *E_invalid_group = N_("invalid group");
static const char *E_bad_spec =
N_("cannot get the login group of a numeric UID");
- static const char *E_cannot_omit_both =
- N_("cannot omit both user and group");
const char *error_msg;
- char *spec; /* A copy we can write on. */
struct passwd *pwd;
struct group *grp;
- char *g, *u, *separator;
- char *groupname;
- char *dot = NULL;
+ char *u;
+ char const *g;
+ char *gname = NULL;
+ uid_t unum = *uid;
+ gid_t gnum = *gid;
error_msg = NULL;
- *username_arg = *groupname_arg = NULL;
- groupname = NULL;
-
- V_STRDUP (spec, spec_arg);
+ *username = *groupname = NULL;
- /* Find the POSIX `:' separator if there is one. */
- separator = strchr (spec, ':');
+ /* Set U and G to nonzero length strings corresponding to user and
+ group specifiers or to NULL. If U is not NULL, it is a newly
+ allocated string. */
- /* If there is no colon, then see if there's a `.'. */
+ u = NULL;
if (separator == NULL)
{
- dot = strchr (spec, '.');
- /* If there's no colon but there is a `.', then first look up the
- whole spec, in case it's an OWNER name that includes a dot.
- If that fails, then we'll try again, but interpreting the `.'
- as a separator. This is a compatible extension to POSIX, since
- the POSIX-required behavior is always tried first. */
+ if (*spec)
+ u = xstrdup (spec);
+ }
+ else
+ {
+ size_t ulen = separator - spec;
+ if (ulen != 0)
+ {
+ u = xclone (spec, ulen + 1);
+ u[ulen] = '\0';
+ }
}
-
- retry:
-
- /* Replace separator with a NUL. */
- if (separator != NULL)
- *separator = '\0';
-
- /* Set U and G to non-zero length strings corresponding to user and
- group specifiers or to NULL. */
- u = (*spec == '\0' ? NULL : spec);
g = (separator == NULL || *(separator + 1) == '\0'
? NULL
: separator + 1);
- if (u == NULL && g == NULL)
- return _(E_cannot_omit_both);
-
#ifdef __DJGPP__
/* Pretend that we are the user U whose group is G. This makes
pwd and grp functions ``know'' about the UID and GID of these. */
error_msg = E_bad_spec;
else
{
- unsigned long int tmp_long;
- if (! (xstrtoul (u, NULL, 10, &tmp_long, "") == LONGINT_OK
- && tmp_long <= MAXUID))
- return _(E_invalid_user);
- *uid = tmp_long;
+ unsigned long int tmp;
+ if (xstrtoul (u, NULL, 10, &tmp, "") == LONGINT_OK
+ && tmp <= MAXUID)
+ unum = tmp;
+ else
+ error_msg = E_invalid_user;
}
}
else
{
- *uid = pwd->pw_uid;
+ unum = pwd->pw_uid;
if (g == NULL && separator != NULL)
{
/* A separator was given, but a group was not specified,
so get the login group. */
- *gid = pwd->pw_gid;
- grp = getgrgid (pwd->pw_gid);
- if (grp == NULL)
- {
- char buf[INT_BUFSIZE_BOUND (uintmax_t)];
- char const *num = umaxtostr (pwd->pw_gid, buf);
- V_STRDUP (groupname, num);
- }
- else
- {
- V_STRDUP (groupname, grp->gr_name);
- }
+ char buf[INT_BUFSIZE_BOUND (uintmax_t)];
+ gnum = pwd->pw_gid;
+ grp = getgrgid (gnum);
+ gname = xstrdup (grp ? grp->gr_name : umaxtostr (gnum, buf));
endgrent ();
}
}
grp = getgrnam (g);
if (grp == NULL)
{
- unsigned long int tmp_long;
- if (! (xstrtoul (g, NULL, 10, &tmp_long, "") == LONGINT_OK
- && tmp_long <= MAXGID))
- return _(E_invalid_group);
- *gid = tmp_long;
+ unsigned long int tmp;
+ if (xstrtoul (g, NULL, 10, &tmp, "") == LONGINT_OK && tmp <= MAXGID)
+ gnum = tmp;
+ else
+ error_msg = E_invalid_group;
}
else
- *gid = grp->gr_gid;
+ gnum = grp->gr_gid;
endgrent (); /* Save a file descriptor. */
-
- if (error_msg == NULL)
- V_STRDUP (groupname, g);
+ gname = xstrdup (g);
}
if (error_msg == NULL)
{
- if (u != NULL)
- *username_arg = xstrdup (u);
-
- if (groupname != NULL)
- *groupname_arg = xstrdup (groupname);
+ *uid = unum;
+ *gid = gnum;
+ *username = u;
+ *groupname = gname;
+ u = NULL;
}
+ else
+ free (gname);
- if (error_msg && dot)
+ free (u);
+ return _(error_msg);
+}
+
+/* Extract from SPEC, which has the form "[user][:.][group]",
+ a USERNAME, UID U, GROUPNAME, and GID G.
+ Either user or group, or both, must be present.
+ If the group is omitted but the separator is given,
+ use the given user's login group.
+ If SPEC contains a `:', then use that as the separator, ignoring
+ any `.'s. If there is no `:', but there is a `.', then first look
+ up the entire SPEC as a login name. If that look-up fails, then
+ try again interpreting the `.' as a separator.
+
+ USERNAME and GROUPNAME will be in newly malloc'd memory.
+ Either one might be NULL instead, indicating that it was not
+ given and the corresponding numeric ID was left unchanged.
+
+ Return NULL if successful, a static error message string if not. */
+
+char const *
+parse_user_spec (char const *spec, uid_t *uid, gid_t *gid,
+ char **username, char **groupname)
+{
+ char const *colon = strchr (spec, ':');
+ char const *error_msg =
+ parse_with_separator (spec, colon, uid, gid, username, groupname);
+
+ if (!colon && error_msg)
{
- separator = dot;
- dot = NULL;
- error_msg = NULL;
- goto retry;
+ /* If there's no colon but there is a dot, and if looking up the
+ whole spec failed (i.e., the spec is not a owner name that
+ includes a dot), then try again, but interpret the dot as a
+ separator. This is a compatible extension to POSIX, since
+ the POSIX-required behavior is always tried first. */
+
+ char const *dot = strchr (spec, '.');
+ if (dot
+ && ! parse_with_separator (spec, dot, uid, gid, username, groupname))
+ error_msg = NULL;
}
- return _(error_msg);
+ return error_msg;
}
#ifdef TEST
projects / platform / upstream / coreutils.git / commitdiff