Use seteuid()/setegid() instead of setreseuid()/setresgid()

It looks like that all supported systems now have support for
_POSIX_SAVED_IDS, so it's safe to use setegid() and setegid() because
those will not change saved used/group IDs.

diff --git a/bin/named/os.c b/bin/named/os.c
index 49fd04df8470a0a9cde90e1d1812ead18f1b8216..031779e4a30101651ecc0b9b2816190464a58524 100644 (file)
--- a/bin/named/os.c
+++ b/bin/named/os.c
@@ -249,115 +249,6 @@ linux_keepcaps(void) {
 
 #endif /* HAVE_LIBCAP */
 
-/*
- * First define compatibility shims if {set,get}res{uid,gid} are not available
- */
-
-#if !HAVE_GETRESGID
-static int
-getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid) {
-       *rgid = -1;
-       *egid = getegid();
-       *sgid = -1;
-
-       return (0);
-}
-#endif /* !HAVE_GETRESGID */
-
-#if !HAVE_SETRESGID
-static int
-setresgid(gid_t rgid, gid_t egid, gid_t sgid) {
-       REQUIRE(rgid == (gid_t)-1);
-       REQUIRE(sgid == (gid_t)-1);
-
-#if HAVE_SETREGID
-       return (setregid(rgid, egid));
-#else  /* HAVE_SETREGID */
-       return (setegid(egid));
-#endif /* HAVE_SETREGID */
-}
-#endif /* !HAVE_SETRESGID */
-
-#if !HAVE_GETRESUID
-static int
-getresuid(uid_t *ruid, uid_t *euid, uid_t *suid) {
-       *ruid = -1;
-       *euid = geteuid();
-       *suid = -1;
-
-       return (0);
-}
-#endif /* !HAVE_GETRESUID */
-
-#if !HAVE_SETRESUID
-static int
-setresuid(uid_t ruid, uid_t euid, uid_t suid) {
-       REQUIRE(ruid == (uid_t)-1);
-       REQUIRE(suid == (uid_t)-1);
-
-#if HAVE_SETREUID
-       return (setreuid(ruid, euid));
-#else  /* HAVE_SETREUID */
-       return (seteuid(euid));
-#endif /* HAVE_SETREUID */
-}
-#endif /* !HAVE_SETRESUID */
-
-static int
-set_effective_gid(gid_t gid) {
-       gid_t oldgid;
-
-       if (getresgid(&(gid_t){ 0 }, &oldgid, &(gid_t){ 0 }) == -1) {
-               return (-1);
-       }
-
-       if (oldgid == gid) {
-               return (0);
-       }
-
-       if (setresgid(-1, gid, -1) == -1) {
-               return (-1);
-       }
-
-       if (getresgid(&(gid_t){ 0 }, &oldgid, &(gid_t){ 0 }) == -1) {
-               return (-1);
-       }
-
-       if (oldgid != gid) {
-               return (-1);
-       }
-
-       return (0);
-}
-
-static int
-set_effective_uid(uid_t uid) {
-       uid_t olduid;
-
-       if (getresuid(&(uid_t){ 0 }, &olduid, &(uid_t){ 0 }) == -1) {
-               return (-1);
-       }
-
-       if (olduid == uid) {
-               return (0);
-       }
-
-       if (setresuid(-1, uid, -1) == -1) {
-               return (-1);
-       }
-
-       if (getresuid(&(uid_t){ 0 }, &olduid, &(uid_t){ 0 }) == -1) {
-               return (-1);
-       }
-
-       if (olduid != uid) {
-               return (-1);
-       }
-
-       /* Success */
-       return (0);
-}
-
 static void
 setperms(uid_t uid, gid_t gid) {
        char strbuf[ISC_STRERRORSIZE];
@@ -366,13 +257,13 @@ setperms(uid_t uid, gid_t gid) {
         * Drop the gid privilege first, because in some cases the gid privilege
         * cannot be dropped after the uid privilege has been dropped.
         */
-       if (set_effective_gid(gid) == -1) {
+       if (setegid(gid) == -1) {
                strerror_r(errno, strbuf, sizeof(strbuf));
                named_main_earlywarning("unable to set effective gid to %d: %s",
                                        gid, strbuf);
        }
 
-       if (set_effective_uid(uid) == -1) {
+       if (seteuid(uid) == -1) {
                strerror_r(errno, strbuf, sizeof(strbuf));
                named_main_earlywarning("unable to set effective uid to %d: %s",
                                        uid, strbuf);
@@ -578,12 +469,12 @@ named_os_changeuser(void) {
 
        done_setuid = true;
 
-       if (setgid(runas_pw->pw_gid) < 0) {
+       if (setgid(runas_pw->pw_gid) == -1) {
                strerror_r(errno, strbuf, sizeof(strbuf));
                named_main_earlyfatal("setgid(): %s", strbuf);
        }
 
-       if (setuid(runas_pw->pw_uid) < 0) {
+       if (setuid(runas_pw->pw_uid) == -1) {
                strerror_r(errno, strbuf, sizeof(strbuf));
                named_main_earlyfatal("setuid(): %s", strbuf);
        }

diff --git a/configure.ac b/configure.ac
index e7ce42c1db13208e583b7e1bf28e8b12ecbe0c98..ecb10b087a00e9d5fcac731be105934dd33b2f42 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -425,12 +425,6 @@ AS_CASE([$host],
 
 AC_CHECK_FUNCS([sysctlbyname])
 
-#
-# Check for uid/gid setting variants
-#
-AC_CHECK_FUNCS([setresuid setreuid getresuid])
-AC_CHECK_FUNCS([setresgid setregid getresgid])
-
 AC_TYPE_SIZE_T
 AC_TYPE_SSIZE_T
 AC_TYPE_UINTPTR_T