[src/trunk]: src/tests/net/net - when running as root, create the socket unde...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a86af7abb08d
branches:  trunk
changeset: 937820:a86af7abb08d
user:      christos <christos%NetBSD.org@localhost>
date:      Thu Aug 27 14:00:01 2020 +0000

description:
- when running as root, create the socket under a different uid/gid to verify
  that it works properly with different users opening the socket.
- verify that linux works the same for both getpeereid() and fstat()

diffstat:

 tests/net/net/t_unix.c |  83 +++++++++++++++++++++++++++++++++++++++++++------
 1 files changed, 73 insertions(+), 10 deletions(-)

diffs (190 lines):

diff -r a7d4350751ef -r a86af7abb08d tests/net/net/t_unix.c
--- a/tests/net/net/t_unix.c    Thu Aug 27 13:44:41 2020 +0000
+++ b/tests/net/net/t_unix.c    Thu Aug 27 14:00:01 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: t_unix.c,v 1.20 2020/08/26 22:52:58 christos Exp $     */
+/*     $NetBSD: t_unix.c,v 1.21 2020/08/27 14:00:01 christos Exp $     */
 
 /*-
  * Copyright (c) 2011 The NetBSD Foundation, Inc.
@@ -36,9 +36,10 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#define _GNU_SOURCE
 #include <sys/cdefs.h>
 #ifdef __RCSID
-__RCSID("$Id: t_unix.c,v 1.20 2020/08/26 22:52:58 christos Exp $");
+__RCSID("$Id: t_unix.c,v 1.21 2020/08/27 14:00:01 christos Exp $");
 #else
 #define getprogname() argv[0]
 #endif
@@ -58,12 +59,19 @@
 #include <errno.h>
 #include <string.h>
 #include <stddef.h>
+#include <stdint.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdbool.h>
 
 #include "test.h"
 
+#define UID 666
+#define GID 999
+
+uid_t srvruid, clntuid;
+gid_t srvrgid, clntgid;
+
 #define OF offsetof(struct sockaddr_un, sun_path)
 
 static void
@@ -130,28 +138,42 @@
 static int
 peercred(int s, uid_t *euid, gid_t *egid, pid_t *pid)
 {
+#ifdef SO_PEERCRED
+       /* Linux */
+# define unpcbid ucred
+# define unp_euid uid
+# define unp_egid gid
+# define unp_pid pid
+# define LOCAL_PEEREID SO_PEERCRED
+# define LEVEL SOL_SOCKET
+#else
+# define LEVEL 0
+#endif
+
 #ifdef LOCAL_PEEREID
+       /* NetBSD */
        struct unpcbid cred;
        socklen_t crl;
        crl = sizeof(cred);
-       if (getsockopt(s, 0, LOCAL_PEEREID, &cred, &crl) == -1)
+       if (getsockopt(s, LEVEL, LOCAL_PEEREID, &cred, &crl) == -1)
                return -1;
        *euid = cred.unp_euid;
        *egid = cred.unp_egid;
        *pid = cred.unp_pid;
        return 0;
 #else
+       /* FreeBSD */
        *pid = -1;
        return getpeereid(s, euid, egid);
 #endif
 }
 
 static int
-check_cred(int fd, bool statit, pid_t checkpid, const char *s)
+check_cred(int fd, bool statit, pid_t checkpid, pid_t otherpid, const char *s)
 {
        pid_t pid;
-       uid_t euid;
-       gid_t egid;
+       uid_t euid, uid;
+       gid_t egid, gid;
 
        if (statit) {
                struct stat st;
@@ -167,8 +189,28 @@
        printf("%s(%s) euid=%jd egid=%jd pid=%jd\n",
            statit ? "fstat" : "peercred", s,
            (intmax_t)euid, (intmax_t)egid, (intmax_t)pid);
-       CHECK_EQUAL(euid, geteuid(), s);
-       CHECK_EQUAL(egid, getegid(), s);
+
+       if (statit) {
+               if (strcmp(s, "server") == 0) {
+                       uid = srvruid;
+                       gid = srvrgid;
+               } else {
+                       uid = clntuid;
+                       gid = clntgid;
+               }
+       } else {
+               if (checkpid != otherpid && strcmp(s, "server") == 0) {
+                       uid = clntuid;
+                       gid = clntgid;
+               } else {
+                       uid = srvruid;
+                       gid = srvrgid;
+               }
+       }
+       fflush(stdout);
+       
+       CHECK_EQUAL(euid, uid, s);
+       CHECK_EQUAL(egid, gid, s);
        CHECK_EQUAL(pid, checkpid, s);
        return 0;
 fail:
@@ -187,6 +229,8 @@
        socklen_t peer_addrlen;
        struct sockaddr_un peer_addr;
 
+       srvruid = geteuid();
+       srvrgid = getegid();
        srvrpid = clntpid = getpid();
        srvr = socket(AF_UNIX, SOCK_STREAM, 0);
        if (srvr == -1)
@@ -207,6 +251,8 @@
 #endif
        sun->sun_family = AF_UNIX;
 
+       unlink(sun->sun_path);
+
        if (bind(srvr, (struct sockaddr *)sun, sl) == -1) {
                if (errno == EINVAL && sl >= 256) {
                        close(srvr);
@@ -214,6 +260,8 @@
                }
                FAIL("bind");
        }
+       if (chmod(sun->sun_path, 0777) == -1)
+               FAIL("chmod `%s'", sun->sun_path);
 
        if (listen(srvr, SOMAXCONN) == -1)
                FAIL("listen");
@@ -223,10 +271,25 @@
                case 0: /* child */
                        srvrpid = getppid();
                        clntpid = getpid();
+                       if (srvruid == 0) {
+                               clntuid = UID;
+                               clntgid = GID;
+                               setgid(clntgid);
+                               setegid(clntgid);
+                               setuid(clntuid);
+                               seteuid(clntuid);
+                       } else {
+                               clntuid = srvruid;
+                               clntgid = srvrgid;
+                       }
                        break;
                case -1:
                        FAIL("fork");
                default:
+                       if (srvruid == 0) {
+                               clntuid = UID;
+                               clntgid = GID;
+                       }
                        break;
                }
        }
@@ -238,7 +301,7 @@
 
                if (connect(clnt, (const struct sockaddr *)sun, sl) == -1)
                        FAIL("connect");
-               check_cred(clnt, statit, srvrpid, "client");
+               check_cred(clnt, statit, srvrpid, clntpid, "client");
 
        }
 
@@ -261,7 +324,7 @@
        }
 
        if (srvrpid == getpid()) {
-               check_cred(acpt, statit, clntpid, "server");
+               check_cred(acpt, statit, clntpid, srvrpid, "server");
                if ((sock_addr = calloc(1, slen)) == NULL)
                        FAIL("calloc");
                sock_addrlen = slen;