uwrap: Add support for real/save uid/gid changing.

diff --git a/src/uid_wrapper.c b/src/uid_wrapper.c
index 560ee6aa8404f45814023cfef586e63eba803df2..a239ea235eaf45211c0df17d7951614412e64f36 100644 (file)
--- a/src/uid_wrapper.c
+++ b/src/uid_wrapper.c
@@ -50,6 +50,9 @@
 #define LIBC_NAME "libc.so"
 
 struct uwrap_libc_fns {
+       int (*_libc_setuid)(uid_t uid);
+       uid_t (*_libc_getuid)(void);
+
 #ifdef HAVE_SETEUID
        int (*_libc_seteuid)(uid_t euid);
 #endif
@@ -60,6 +63,9 @@ struct uwrap_libc_fns {
        int (*_libc_setresuid)(uid_t ruid, uid_t euid, uid_t suid);
 #endif
        uid_t (*_libc_geteuid)(void);
+
+       int (*_libc_setgid)(gid_t gid);
+       gid_t (*_libc_getgid)(void);
 #ifdef HAVE_SETEGID
        int (*_libc_setegid)(uid_t egid);
 #endif
@@ -72,8 +78,6 @@ struct uwrap_libc_fns {
        gid_t (*_libc_getegid)(void);
        int (*_libc_getgroups)(int size, gid_t list[]);
        int (*_libc_setgroups)(size_t size, const gid_t *list);
-       uid_t (*_libc_getuid)(void);
-       gid_t (*_libc_getgid)(void);
 #ifdef HAVE_SYSCALL
        long int (*_libc_syscall)(long int sysno, ...);
 #endif
@@ -142,6 +146,9 @@ static void uwrap_libc_init(struct uwrap *u)
                exit(-1);
        }
 
+       *(void **) (&u->libc.fns._libc_setuid) = uwrap_libc_fn(u, "setuid");
+       *(void **) (&u->libc.fns._libc_getuid) = uwrap_libc_fn(u, "getuid");
+
 #ifdef HAVE_SETEUID
        *(void **) (&u->libc.fns._libc_seteuid) = uwrap_libc_fn(u, "seteuid");
 #endif
@@ -152,6 +159,9 @@ static void uwrap_libc_init(struct uwrap *u)
        *(void **) (&u->libc.fns._libc_setresuid) = uwrap_libc_fn(u, "setresuid");
 #endif
        *(void **) (&u->libc.fns._libc_geteuid) = uwrap_libc_fn(u, "geteuid");
+
+       *(void **) (&u->libc.fns._libc_setgid) = uwrap_libc_fn(u, "setgid");
+       *(void **) (&u->libc.fns._libc_getgid) = uwrap_libc_fn(u, "getgid");
 #ifdef HAVE_SETEGID
        *(void **) (&u->libc.fns._libc_setegid) = uwrap_libc_fn(u, "setegid");
 #endif
@@ -204,19 +214,55 @@ static int uwrap_enabled(void)
 
 static int uwrap_setresuid(uid_t ruid, uid_t euid, uid_t suid)
 {
-       /* assume for now that the ruid stays as root */
-       (void) ruid;
-       (void) suid;
+       if (ruid == (uid_t)-1 && euid == (uid_t)-1 && suid == (uid_t)-1) {
+               errno = EINVAL;
+               return -1;
+       }
+
+       if (ruid != (uid_t)-1) {
+               uwrap.ruid = ruid;
+       }
 
-       if (euid == 0) {
-               uwrap.euid = uwrap.myuid;
-       } else {
+       if (euid != (uid_t)-1) {
                uwrap.euid = euid;
        }
 
+       if (suid != (uid_t)-1) {
+               uwrap.suid = suid;
+       }
+
        return 0;
 }
 
+/*
+ * SETUID
+ */
+int setuid(uid_t uid)
+{
+       if (!uwrap_enabled()) {
+               return uwrap.libc.fns._libc_setuid(uid);
+       }
+
+       return uwrap_setresuid(uid, -1, -1);
+}
+
+/*
+ * GETUID
+ */
+static uid_t uwrap_getuid(void)
+{
+       return uwrap.ruid;
+}
+
+uid_t getuid(void)
+{
+       if (!uwrap_enabled()) {
+               return uwrap.libc.fns._libc_getuid();
+       }
+
+       return uwrap_getuid();
+}
+
 #ifdef HAVE_SETEUID
 int seteuid(uid_t euid)
 {
@@ -236,6 +282,11 @@ int seteuid(uid_t euid)
 #ifdef HAVE_SETREUID
 int setreuid(uid_t ruid, uid_t euid)
 {
+       if (ruid == (uid_t)-1 && euid == (uid_t)-1) {
+               errno = EINVAL;
+               return -1;
+       }
+
        if (!uwrap_enabled()) {
                return uwrap.libc.fns._libc_setreuid(ruid, euid);
        }
@@ -269,18 +320,66 @@ uid_t geteuid(void)
        return uwrap_geteuid();
 }
 
+/*
+ * SETGID
+ */
+static int uwrap_setgid(gid_t gid)
+{
+       if (gid == (gid_t)-1) {
+               errno = EINVAL;
+               return -1;
+       }
+
+       uwrap.rgid = gid;
+
+       return 0;
+}
+
+int setgid(gid_t gid)
+{
+       if (!uwrap_enabled()) {
+               return uwrap.libc.fns._libc_setgid(gid);
+       }
+
+       return uwrap_setgid(gid);
+}
+
+/*
+ * GETGID
+ */
+static gid_t uwrap_getgid(void)
+{
+       return uwrap.ruid;
+}
+
+gid_t getgid(void)
+{
+       if (!uwrap_enabled()) {
+               return uwrap.libc.fns._libc_getgid();
+       }
+
+       return uwrap_getgid();
+}
+
 static int uwrap_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 {
-       /* assume for now that the ruid stays as root */
-       (void) rgid;
-       (void) sgid;
+       if (rgid == (gid_t)-1 && egid == (gid_t)-1 && sgid == (gid_t)-1) {
+               errno = EINVAL;
+               return -1;
+       }
+
+       if (rgid != (gid_t)-1) {
+               uwrap.rgid = rgid;
+       }
 
-       if (egid == 0) {
-               uwrap.egid = uwrap.mygid;
-       } else {
+       if (egid != (gid_t)-1) {
                uwrap.egid = egid;
        }
 
+       if (sgid != (gid_t)-1) {
+               uwrap.sgid = sgid;
+       }
+
        return 0;
 }
 
@@ -389,36 +488,6 @@ int getgroups(int size, gid_t *list)
        return uwrap_getgroups(size, list);
 }
 
-static uid_t uwrap_getuid(void)
-{
-       /* we don't simulate ruid changing */
-       return 0;
-}
-
-uid_t getuid(void)
-{
-       if (!uwrap_enabled()) {
-               return uwrap.libc.fns._libc_getuid();
-       }
-
-       return uwrap_getuid();
-}
-
-static gid_t uwrap_getgid(void)
-{
-       /* we don't simulate rgid changing */
-       return 0;
-}
-
-gid_t getgid(void)
-{
-       if (!uwrap_enabled()) {
-               return uwrap.libc.fns._libc_getgid();
-       }
-
-       return uwrap_getgid();
-}
-
 static long int libc_vsyscall(long int sysno, va_list va)
 {
        long int args[8];
@@ -457,7 +526,7 @@ static long int uwrap_syscall (long int sysno, va_list vp)
                        {
                                gid_t gid = (gid_t) va_arg(vp, int);
 
-                               rc = setgid(gid);
+                               rc = uwrap_setresgid(gid, -1, -1);
                        }
                        break;
                case SYS_setregid:
@@ -492,7 +561,7 @@ static long int uwrap_syscall (long int sysno, va_list vp)
                        {
                                uid_t uid = (uid_t) va_arg(vp, int);
 
-                               rc = setuid(uid);
+                               rc = uwrap_setresuid(uid, -1, -1);
                        }
                        break;
                case SYS_setreuid: