From: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
Move unix_stream_server__listen_with_lock() and associated routines
and data types out of unix-socket.[ch] and into their own source file.
We added code to safely create a Unix domain socket using a lockfile in:
9406d12e14 (unix-socket: create `unix_stream_server__listen_with_lock()`,
2021-02-13). This code conceptually exists at a higher-level than the
core unix_stream_connect() and unix_stream_listen() routines that it
consumes and should be isolated for clarity.
Signed-off-by: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
---
Makefile | 1 +
compat/simple-ipc/ipc-unix-socket.c | 1 +
contrib/buildsystems/CMakeLists.txt | 2 +-
unix-socket.c | 120 ---------------------------
unix-socket.h | 26 ------
unix-stream-server.c | 124 ++++++++++++++++++++++++++++
unix-stream-server.h | 32 +++++++
7 files changed, 159 insertions(+), 147 deletions(-)
create mode 100644 unix-stream-server.c
create mode 100644 unix-stream-server.h
diff --git a/Makefile b/Makefile
index 93f2e7ca9e1f..dfc37b0480e4 100644
--- a/Makefile
+++ b/Makefile
@@ -1678,6 +1678,7 @@ ifdef NO_UNIX_SOCKETS
BASIC_CFLAGS += -DNO_UNIX_SOCKETS
else
LIB_OBJS += unix-socket.o
+ LIB_OBJS += unix-stream-server.o
LIB_OBJS += compat/simple-ipc/ipc-shared.o
LIB_OBJS += compat/simple-ipc/ipc-unix-socket.o
endif
diff --git a/compat/simple-ipc/ipc-unix-socket.c b/compat/simple-ipc/ipc-unix-socket.c
index b7fd0b34329e..b0264ca6cdc6 100644
--- a/compat/simple-ipc/ipc-unix-socket.c
+++ b/compat/simple-ipc/ipc-unix-socket.c
@@ -4,6 +4,7 @@
#include "pkt-line.h"
#include "thread-utils.h"
#include "unix-socket.h"
+#include "unix-stream-server.h"
#ifdef NO_UNIX_SOCKETS
#error compat/simple-ipc/ipc-unix-socket.c requires Unix sockets
diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt
index 4c27a373414a..629a1817459b 100644
--- a/contrib/buildsystems/CMakeLists.txt
+++ b/contrib/buildsystems/CMakeLists.txt
@@ -243,7 +243,7 @@ if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
add_compile_definitions(PROCFS_EXECUTABLE_PATH="/proc/self/exe" HAVE_DEV_TTY )
- list(APPEND compat_SOURCES unix-socket.c)
+ list(APPEND compat_SOURCES unix-socket.c unix-stream-server.c)
endif()
if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
diff --git a/unix-socket.c b/unix-socket.c
index c9ea1de43bd2..e0be1badb58d 100644
--- a/unix-socket.c
+++ b/unix-socket.c
@@ -1,8 +1,6 @@
#include "cache.h"
-#include "lockfile.h"
#include "unix-socket.h"
-#define DEFAULT_UNIX_STREAM_LISTEN_TIMEOUT (100)
#define DEFAULT_UNIX_STREAM_LISTEN_BACKLOG (5)
static int chdir_len(const char *orig, int len)
@@ -136,121 +134,3 @@ int unix_stream_listen(const char *path,
errno = saved_errno;
return -1;
}
-
-static int is_another_server_alive(const char *path,
- const struct unix_stream_listen_opts *opts)
-{
- struct stat st;
- int fd;
-
- if (!lstat(path, &st) && S_ISSOCK(st.st_mode)) {
- /*
- * A socket-inode exists on disk at `path`, but we
- * don't know whether it belongs to an active server
- * or whether the last server died without cleaning
- * up.
- *
- * Poke it with a trivial connection to try to find
- * out.
- */
- fd = unix_stream_connect(path, opts->disallow_chdir);
- if (fd >= 0) {
- close(fd);
- return 1;
- }
- }
-
- return 0;
-}
-
-struct unix_stream_server_socket *unix_stream_server__listen_with_lock(
- const char *path,
- const struct unix_stream_listen_opts *opts)
-{
- struct lock_file lock = LOCK_INIT;
- long timeout;
- int fd_socket;
- struct unix_stream_server_socket *server_socket;
-
- timeout = opts->timeout_ms;
- if (opts->timeout_ms <= 0)
- timeout = DEFAULT_UNIX_STREAM_LISTEN_TIMEOUT;
-
- /*
- * Create a lock at "<path>.lock" if we can.
- */
- if (hold_lock_file_for_update_timeout(&lock, path, 0, timeout) < 0) {
- error_errno(_("could not lock listener socket '%s'"), path);
- return NULL;
- }
-
- /*
- * If another server is listening on "<path>" give up. We do not
- * want to create a socket and steal future connections from them.
- */
- if (is_another_server_alive(path, opts)) {
- errno = EADDRINUSE;
- error_errno(_("listener socket already in use '%s'"), path);
- rollback_lock_file(&lock);
- return NULL;
- }
-
- /*
- * Create and bind to a Unix domain socket at "<path>".
- */
- fd_socket = unix_stream_listen(path, opts);
- if (fd_socket < 0) {
- error_errno(_("could not create listener socket '%s'"), path);
- rollback_lock_file(&lock);
- return NULL;
- }
-
- server_socket = xcalloc(1, sizeof(*server_socket));
- server_socket->path_socket = strdup(path);
- server_socket->fd_socket = fd_socket;
- lstat(path, &server_socket->st_socket);
-
- /*
- * Always rollback (just delete) "<path>.lock" because we already created
- * "<path>" as a socket and do not want to commit_lock to do the atomic
- * rename trick.
- */
- rollback_lock_file(&lock);
-
- return server_socket;
-}
-
-void unix_stream_server__free(
- struct unix_stream_server_socket *server_socket)
-{
- if (!server_socket)
- return;
-
- if (server_socket->fd_socket >= 0) {
- if (!unix_stream_server__was_stolen(server_socket))
- unlink(server_socket->path_socket);
- close(server_socket->fd_socket);
- }
-
- free(server_socket->path_socket);
- free(server_socket);
-}
-
-int unix_stream_server__was_stolen(
- struct unix_stream_server_socket *server_socket)
-{
- struct stat st_now;
-
- if (!server_socket)
- return 0;
-
- if (lstat(server_socket->path_socket, &st_now) == -1)
- return 1;
-
- if (st_now.st_ino != server_socket->st_socket.st_ino)
- return 1;
-
- /* We might also consider the ctime on some platforms. */
-
- return 0;
-}
diff --git a/unix-socket.h b/unix-socket.h
index bec925ee0213..b079e79cb3e1 100644
--- a/unix-socket.h
+++ b/unix-socket.h
@@ -18,30 +18,4 @@ int unix_stream_connect(const char *path, int disallow_chdir);
int unix_stream_listen(const char *path,
const struct unix_stream_listen_opts *opts);
-struct unix_stream_server_socket {
- char *path_socket;
- struct stat st_socket;
- int fd_socket;
-};
-
-/*
- * Create a Unix Domain Socket at the given path under the protection
- * of a '.lock' lockfile.
- */
-struct unix_stream_server_socket *unix_stream_server__listen_with_lock(
- const char *path,
- const struct unix_stream_listen_opts *opts);
-
-/*
- * Close and delete the socket.
- */
-void unix_stream_server__free(
- struct unix_stream_server_socket *server_socket);
-
-/*
- * Return 1 if the inode of the pathname to our socket changes.
- */
-int unix_stream_server__was_stolen(
- struct unix_stream_server_socket *server_socket);
-
#endif /* UNIX_SOCKET_H */
diff --git a/unix-stream-server.c b/unix-stream-server.c
new file mode 100644
index 000000000000..ad175ba731ca
--- /dev/null
+++ b/unix-stream-server.c
@@ -0,0 +1,124 @@
+#include "cache.h"
+#include "lockfile.h"
+#include "unix-socket.h"
+#include "unix-stream-server.h"
+
+#define DEFAULT_UNIX_STREAM_LISTEN_TIMEOUT (100)
+
+static int is_another_server_alive(const char *path,
+ const struct unix_stream_listen_opts *opts)
+{
+ struct stat st;
+ int fd;
+
+ if (!lstat(path, &st) && S_ISSOCK(st.st_mode)) {
+ /*
+ * A socket-inode exists on disk at `path`, but we
+ * don't know whether it belongs to an active server
+ * or whether the last server died without cleaning
+ * up.
+ *
+ * Poke it with a trivial connection to try to find
+ * out.
+ */
+ fd = unix_stream_connect(path, opts->disallow_chdir);
+ if (fd >= 0) {
+ close(fd);
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+struct unix_stream_server_socket *unix_stream_server__listen_with_lock(
+ const char *path,
+ const struct unix_stream_listen_opts *opts)
+{
+ struct lock_file lock = LOCK_INIT;
+ long timeout;
+ int fd_socket;
+ struct unix_stream_server_socket *server_socket;
+
+ timeout = opts->timeout_ms;
+ if (opts->timeout_ms <= 0)
+ timeout = DEFAULT_UNIX_STREAM_LISTEN_TIMEOUT;
+
+ /*
+ * Create a lock at "<path>.lock" if we can.
+ */
+ if (hold_lock_file_for_update_timeout(&lock, path, 0, timeout) < 0) {
+ error_errno(_("could not lock listener socket '%s'"), path);
+ return NULL;
+ }
+
+ /*
+ * If another server is listening on "<path>" give up. We do not
+ * want to create a socket and steal future connections from them.
+ */
+ if (is_another_server_alive(path, opts)) {
+ errno = EADDRINUSE;
+ error_errno(_("listener socket already in use '%s'"), path);
+ rollback_lock_file(&lock);
+ return NULL;
+ }
+
+ /*
+ * Create and bind to a Unix domain socket at "<path>".
+ */
+ fd_socket = unix_stream_listen(path, opts);
+ if (fd_socket < 0) {
+ error_errno(_("could not create listener socket '%s'"), path);
+ rollback_lock_file(&lock);
+ return NULL;
+ }
+
+ server_socket = xcalloc(1, sizeof(*server_socket));
+ server_socket->path_socket = strdup(path);
+ server_socket->fd_socket = fd_socket;
+ lstat(path, &server_socket->st_socket);
+
+ /*
+ * Always rollback (just delete) "<path>.lock" because we already created
+ * "<path>" as a socket and do not want to commit_lock to do the atomic
+ * rename trick.
+ */
+ rollback_lock_file(&lock);
+
+ return server_socket;
+}
+
+void unix_stream_server__free(
+ struct unix_stream_server_socket *server_socket)
+{
+ if (!server_socket)
+ return;
+
+ if (server_socket->fd_socket >= 0) {
+ if (!unix_stream_server__was_stolen(server_socket))
+ unlink(server_socket->path_socket);
+ close(server_socket->fd_socket);
+ }
+
+ free(server_socket->path_socket);
+ free(server_socket);
+}
+
+int unix_stream_server__was_stolen(
+ struct unix_stream_server_socket *server_socket)
+{
+ struct stat st_now;
+
+ if (!server_socket)
+ return 0;
+
+ if (lstat(server_socket->path_socket, &st_now) == -1)
+ return 1;
+
+ if (st_now.st_ino != server_socket->st_socket.st_ino)
+ return 1;
+
+ /* We might also consider the ctime on some platforms. */
+
+ return 0;
+}
diff --git a/unix-stream-server.h b/unix-stream-server.h
new file mode 100644
index 000000000000..745849e31c30
--- /dev/null
+++ b/unix-stream-server.h
@@ -0,0 +1,32 @@
+#ifndef UNIX_STREAM_SERVER_H
+#define UNIX_STREAM_SERVER_H
+
+#include "unix-socket.h"
+
+struct unix_stream_server_socket {
+ char *path_socket;
+ struct stat st_socket;
+ int fd_socket;
+};
+
+/*
+ * Create a Unix Domain Socket at the given path under the protection
+ * of a '.lock' lockfile.
+ */
+struct unix_stream_server_socket *unix_stream_server__listen_with_lock(
+ const char *path,
+ const struct unix_stream_listen_opts *opts);
+
+/*
+ * Close and delete the socket.
+ */
+void unix_stream_server__free(
+ struct unix_stream_server_socket *server_socket);
+
+/*
+ * Return 1 if the inode of the pathname to our socket changes.
+ */
+int unix_stream_server__was_stolen(
+ struct unix_stream_server_socket *server_socket);
+
+#endif /* UNIX_STREAM_SERVER_H */
--
gitgitgadget
