From d0986e46b74de3b131fccbf79bd00de5ff054f71 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>

Date: Sat, 6 Jun 2015 18:59:27 -0400

Subject: [PATCH] sd-bus: do not use per-datagram auxiliary information

SELinux information cannot be retrieved this way, since we are

using stream unix sockets and SCM_SECURITY does not work for

them.

SCM_CREDENTIALS use dropped to be consistent. We also should

get this information at connection time.

https://bugzilla.redhat.com/show_bug.cgi?id=1224211

"SCM_SECURITY was only added for datagram sockets."

Cherry-picked from: d868f2a

Related: #1230190

---

 src/libsystemd/sd-bus/bus-socket.c | 70 +++++-------------------------

 1 file changed, 12 insertions(+), 58 deletions(-)

diff --git a/src/libsystemd/sd-bus/bus-socket.c b/src/libsystemd/sd-bus/bus-socket.c

index 52883fa8cd..abd9ece016 100644

--- a/src/libsystemd/sd-bus/bus-socket.c

+++ b/src/libsystemd/sd-bus/bus-socket.c

@@ -501,9 +501,7 @@ static int bus_socket_read_auth(sd_bus *b) {

         void *p;

         union {

                 struct cmsghdr cmsghdr;

-                uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) +

-                            CMSG_SPACE(sizeof(struct ucred)) +

-                            CMSG_SPACE(NAME_MAX)]; /*selinux label */

+                uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX)];

         } control;

         struct cmsghdr *cmsg;

         bool handle_cmsg = false;

@@ -556,8 +554,8 @@ static int bus_socket_read_auth(sd_bus *b) {

         b->rbuffer_size += k;

-        if (handle_cmsg) {

-                for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) {

+        if (handle_cmsg)

+                for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg))

                         if (cmsg->cmsg_level == SOL_SOCKET &&

                             cmsg->cmsg_type == SCM_RIGHTS) {

                                 int j;

@@ -568,31 +566,9 @@ static int bus_socket_read_auth(sd_bus *b) {

                                 j = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);

                                 close_many((int*) CMSG_DATA(cmsg), j);

                                 return -EIO;

-

-                        } else if (cmsg->cmsg_level == SOL_SOCKET &&

-                                   cmsg->cmsg_type == SCM_CREDENTIALS &&

-                                   cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {

-

-                                /* Ignore bogus data, which we might

-                                 * get on socketpair() sockets */

-                                if (((struct ucred*) CMSG_DATA(cmsg))->pid != 0) {

-                                        memcpy(&b->ucred, CMSG_DATA(cmsg), sizeof(struct ucred));

-                                        b->ucred_valid = true;

-                                }

-

-                        } else if (cmsg->cmsg_level == SOL_SOCKET &&

-                                   cmsg->cmsg_type == SCM_SECURITY) {

-

-                                size_t l;

-

-                                l = cmsg->cmsg_len - CMSG_LEN(0);

-                                if (l > 0) {

-                                        memcpy(&b->label, CMSG_DATA(cmsg), l);

-                                        b->label[l] = 0;

-                                }

-                        }

-                }

-        }

+                        } else

+                                log_debug("Got unexpected auxiliary data with level=%d and type=%d",

+                                          cmsg->cmsg_level, cmsg->cmsg_type);

         r = bus_socket_auth_verify(b);

         if (r != 0)

@@ -945,9 +921,7 @@ int bus_socket_read_message(sd_bus *bus) {

         void *b;

         union {

                 struct cmsghdr cmsghdr;

-                uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) +

-                            CMSG_SPACE(sizeof(struct ucred)) +

-                            CMSG_SPACE(NAME_MAX)]; /*selinux label */

+                uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX)];

         } control;

         struct cmsghdr *cmsg;

         bool handle_cmsg = false;

@@ -995,8 +969,8 @@ int bus_socket_read_message(sd_bus *bus) {

         bus->rbuffer_size += k;

-        if (handle_cmsg) {

-                for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) {

+        if (handle_cmsg)

+                for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg))

                         if (cmsg->cmsg_level == SOL_SOCKET &&

                             cmsg->cmsg_type == SCM_RIGHTS) {

                                 int n, *f;

@@ -1021,29 +995,9 @@ int bus_socket_read_message(sd_bus *bus) {

                                 memcpy(f + bus->n_fds, CMSG_DATA(cmsg), n * sizeof(int));

                                 bus->fds = f;

                                 bus->n_fds += n;

-                        } else if (cmsg->cmsg_level == SOL_SOCKET &&

-                                   cmsg->cmsg_type == SCM_CREDENTIALS &&

-                                   cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {

-

-                                /* Ignore bogus data, which we might

-                                 * get on socketpair() sockets */

-                                if (((struct ucred*) CMSG_DATA(cmsg))->pid != 0) {

-                                        memcpy(&bus->ucred, CMSG_DATA(cmsg), sizeof(struct ucred));

-                                        bus->ucred_valid = true;

-                                }

-

-                        } else if (cmsg->cmsg_level == SOL_SOCKET &&

-                                   cmsg->cmsg_type == SCM_SECURITY) {

-

-                                size_t l;

-                                l = cmsg->cmsg_len - CMSG_LEN(0);

-                                if (l > 0) {

-                                        memcpy(&bus->label, CMSG_DATA(cmsg), l);

-                                        bus->label[l] = 0;

-                                }

-                        }

-                }

-        }

+                        } else

+                                log_debug("Got unexpected auxiliary data with level=%d and type=%d",

+                                          cmsg->cmsg_level, cmsg->cmsg_type);

         r = bus_socket_read_message_need(bus, &need);

         if (r < 0)