[PATCH 3/8] server: add *BSD credentials support.
Leonid Bobrov
mazocomp at disroot.org
Fri Feb 8 13:13:36 UTC 2019
Signed-off-by: Leonid Bobrov <mazocomp at disroot.org>
---
configure.ac | 3 ++
src/wayland-server.c | 46 ++++++++++++++++++++++
src/wayland-shm.c | 92 +++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 140 insertions(+), 1 deletion(-)
diff --git a/configure.ac b/configure.ac
index 912330e..d106a41 100644
--- a/configure.ac
+++ b/configure.ac
@@ -65,6 +65,9 @@ AC_SUBST(GCC_CFLAGS)
AC_CHECK_HEADERS([sys/prctl.h])
AC_CHECK_FUNCS([accept4 mkostemp posix_fallocate prctl])
+# Credential support on BSD
+AC_CHECK_HEADERS([sys/ucred.h])
+
# Replacement for /proc on BSD
AC_CHECK_HEADERS([kvm.h])
SAVE_LIBS="$LIBS"
diff --git a/src/wayland-server.c b/src/wayland-server.c
index 19f6a76..f4cdbf3 100644
--- a/src/wayland-server.c
+++ b/src/wayland-server.c
@@ -25,6 +25,13 @@
#define _GNU_SOURCE
+#include "../config.h"
+
+#ifdef HAVE_SYS_UCRED_H
+#include <sys/types.h>
+#include <sys/ucred.h>
+#endif
+
#include <stdlib.h>
#include <stdint.h>
#include <stddef.h>
@@ -77,7 +84,13 @@ struct wl_client {
struct wl_list link;
struct wl_map objects;
struct wl_priv_signal destroy_signal;
+#ifdef HAVE_SYS_UCRED_H
+ /* BSD */
+ struct xucred xucred;
+#else
+ /* Linux */
struct ucred ucred;
+#endif
int error;
struct wl_priv_signal resource_created_signal;
};
@@ -312,7 +325,11 @@ wl_resource_post_error(struct wl_resource *resource,
static void
destroy_client_with_error(struct wl_client *client, const char *reason)
{
+#ifdef HAVE_SYS_UCRED_H
+ wl_log("%s (uid %u)\n", reason, client->xucred.cr_uid);
+#else
wl_log("%s (pid %u)\n", reason, client->ucred.pid);
+#endif
wl_client_destroy(client);
}
@@ -526,10 +543,29 @@ wl_client_create(struct wl_display *display, int fd)
if (!client->source)
goto err_client;
+#ifndef SO_PEERCRED
+/* FreeBSD */
+# define SO_PEERCRED LOCAL_PEERCRED
+#endif
+
+#ifdef HAVE_SYS_UCRED_H
+ /* BSD */
+ len = sizeof client->xucred;
+ if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED,
+ &client->xucred, &len) < 0
+# ifdef XUCRED_VERSION
+ /* FreeBSD */
+ || client->xucred.cr_version != XUCRED_VERSION
+# endif
+ )
+ goto err_source;
+#else
+ /* Linux */
len = sizeof client->ucred;
if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED,
&client->ucred, &len) < 0)
goto err_source;
+#endif
client->connection = wl_connection_create(fd);
if (client->connection == NULL)
@@ -583,12 +619,22 @@ WL_EXPORT void
wl_client_get_credentials(struct wl_client *client,
pid_t *pid, uid_t *uid, gid_t *gid)
{
+#ifdef HAVE_SYS_UCRED_H
+ /* BSD */
+ *pid = 0; /* FIXME: pid is not defined on BSD */
+ if (uid)
+ *uid = client->xucred.cr_uid;
+ if (gid)
+ *gid = client->xucred.cr_gid;
+#else
+ /* Linux */
if (pid)
*pid = client->ucred.pid;
if (uid)
*uid = client->ucred.uid;
if (gid)
*gid = client->ucred.gid;
+#endif
}
/** Get the file descriptor for the client
diff --git a/src/wayland-shm.c b/src/wayland-shm.c
index 4191231..dbaf464 100644
--- a/src/wayland-shm.c
+++ b/src/wayland-shm.c
@@ -30,6 +30,8 @@
#define _GNU_SOURCE
+#include "../config.h"
+
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
@@ -59,6 +61,9 @@ struct wl_shm_pool {
char *data;
int32_t size;
int32_t new_size;
+#ifdef HAVE_SYS_UCRED_H
+ int fd;
+#endif
};
struct wl_shm_buffer {
@@ -76,15 +81,91 @@ struct wl_shm_sigbus_data {
int fallback_mapping_used;
};
+#ifdef HAVE_MREMAP
+static void *
+mremap_compat_maymove(void *old_address, size_t old_size, size_t new_size,
+ int old_prot, int old_flags, int old_fd)
+{
+ return mremap(old_address, old_size, new_size, MREMAP_MAYMOVE);
+}
+#else
+static void *
+mremap_compat_maymove(void *old_address, size_t old_size, size_t new_size,
+ int old_prot, int old_flags, int old_fd)
+{
+ /* FreeBSD doesn't support mremap() yet, so we have to emulate it.
+ * This assumes MREMAP_MAYMOVE is the only flag in use. */
+ if (new_size == old_size) {
+ return old_address;
+ } else if (new_size < old_size) {
+ /* Shrinking: munmap() the spare region. */
+ munmap(old_address + old_size, new_size - old_size);
+ return old_address;
+ } else {
+ void *ret;
+
+ /* Growing. Try and mmap() the extra region at the end of
+ * our existing allocation. If that gets mapped in the
+ * wrong place, fall back to mmap()ing an entirely new
+ * region of new_size and copying the data across. */
+ ret = mmap(old_address + old_size, new_size - old_size,
+ old_prot, old_flags, old_fd, 0);
+
+/* FIXME TODO: msync() before munmap()? */
+ if (ret == MAP_FAILED) {
+ /* Total failure! */
+ return ret;
+ } else if (ret == old_address + old_size) {
+ /* Success. */
+ return old_address;
+ } else if (ret != old_address + old_size) {
+ /* Partial failure. Fall back to mapping an
+ * entirely new region. Unmap the region we
+ * just mapped first. */
+ munmap(ret, new_size - old_size);
+
+ /* Map an entirely new region. */
+ ret = mmap(NULL, new_size,
+ old_prot, old_flags, old_fd, 0);
+ if (ret == MAP_FAILED) {
+ /* Total failure! */
+ return ret;
+ }
+
+ /* Copy the old data across. Implicit assumption
+ * that the old and new regions don't overlap. */
+ memcpy(ret, old_address, old_size);
+
+ /* Unmap the old region. */
+ munmap(old_address, old_size);
+
+ return ret;
+ }
+ }
+
+ /* Unreachable. */
+ return MAP_FAILED;
+}
+#endif
+
static void
shm_pool_finish_resize(struct wl_shm_pool *pool)
{
void *data;
+#ifdef HAVE_SYS_UCRED_H
+ int fd = -1;
+#endif
if (pool->size == pool->new_size)
return;
+#ifdef HAVE_SYS_UCRED_H
+ fd = pool->fd;
+ data = mremap_compat_maymove(pool->data, pool->size, pool->new_size,
+ PROT_READ|PROT_WRITE, MAP_SHARED, fd);
+#else
data = mremap(pool->data, pool->size, pool->new_size, MREMAP_MAYMOVE);
+#endif
if (data == MAP_FAILED) {
wl_resource_post_error(pool->resource,
WL_SHM_ERROR_INVALID_FD,
@@ -110,6 +191,10 @@ shm_pool_unref(struct wl_shm_pool *pool, bool external)
if (pool->internal_refcount + pool->external_refcount)
return;
+#ifdef HAVE_SYS_UCRED_H
+ close(pool->fd);
+#endif
+
munmap(pool->data, pool->size);
free(pool);
}
@@ -284,7 +369,13 @@ shm_create_pool(struct wl_client *client, struct wl_resource *resource,
"failed mmap fd %d: %m", fd);
goto err_free;
}
+#ifdef HAVE_SYS_UCRED_H
+ /* We need to keep the FD around on FreeBSD so we can implement
+ * mremap(). See: mremap_compat_maymove(). */
+ pool->fd = fd;
+#else
close(fd);
+#endif
pool->resource =
wl_resource_create(client, &wl_shm_pool_interface, 1, id);
@@ -364,7 +455,6 @@ wl_shm_buffer_get_stride(struct wl_shm_buffer *buffer)
return buffer->stride;
}
-
/** Get a pointer to the memory for the SHM buffer
*
* \param buffer The buffer object
--
2.20.1
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