diff --git a/contrib/selinux/passt-repair.te b/contrib/selinux/passt-repair.te
index f171be6..7157dfb 100644
--- a/contrib/selinux/passt-repair.te
+++ b/contrib/selinux/passt-repair.te
@@ -61,11 +61,11 @@ allow passt_repair_t unconfined_t:unix_stream_socket { connectto read write };
allow passt_repair_t passt_t:unix_stream_socket { connectto read write };
allow passt_repair_t user_tmp_t:unix_stream_socket { connectto read write };
-allow passt_repair_t user_tmp_t:dir search;
+allow passt_repair_t user_tmp_t:dir { getattr read search watch };
-allow passt_repair_t unconfined_t:sock_file { read write };
-allow passt_repair_t passt_t:sock_file { read write };
-allow passt_repair_t user_tmp_t:sock_file { read write };
+allow passt_repair_t unconfined_t:sock_file { getattr read write };
+allow passt_repair_t passt_t:sock_file { getattr read write };
+allow passt_repair_t user_tmp_t:sock_file { getattr read write };
allow passt_repair_t unconfined_t:tcp_socket { read setopt write };
allow passt_repair_t passt_t:tcp_socket { read setopt write };
@@ -80,8 +80,8 @@ allow passt_repair_t passt_t:tcp_socket { read setopt write };
allow passt_repair_t qemu_var_run_t:unix_stream_socket { connectto read write };
allow passt_repair_t virt_var_run_t:unix_stream_socket { connectto read write };
-allow passt_repair_t qemu_var_run_t:dir search;
-allow passt_repair_t virt_var_run_t:dir search;
+allow passt_repair_t qemu_var_run_t:dir { getattr read search watch };
+allow passt_repair_t virt_var_run_t:dir { getattr read search watch };
-allow passt_repair_t qemu_var_run_t:sock_file { read write };
-allow passt_repair_t virt_var_run_t:sock_file { read write };
+allow passt_repair_t qemu_var_run_t:sock_file { getattr read write };
+allow passt_repair_t virt_var_run_t:sock_file { getattr read write };
diff --git a/passt-repair.1 b/passt-repair.1
index 7c1b140..e65aadd 100644
--- a/passt-repair.1
+++ b/passt-repair.1
@@ -16,13 +16,17 @@
.B passt-repair
is a privileged helper setting and clearing repair mode on TCP sockets on behalf
of \fBpasst\fR(1), as instructed via single-byte commands over a UNIX domain
-socket, specified by \fIPATH\fR.
+socket.
It can be used to migrate TCP connections between guests without granting
additional capabilities to \fBpasst\fR(1) itself: to migrate TCP connections,
\fBpasst\fR(1) leverages repair mode, which needs the \fBCAP_NET_ADMIN\fR
capability (see \fBcapabilities\fR(7)) to be set or cleared.
+If \fIPATH\fR represents a UNIX domain socket, \fBpasst-repair\fR(1) attempts to
+connect to it. If it is a directory, \fBpasst-repair\fR(1) waits until a file
+ending with \fI.repair\fR appears in it, and then attempts to connect to it.
+
.SH PROTOCOL
\fBpasst-repair\fR(1) connects to \fBpasst\fR(1) using the socket specified via
diff --git a/passt-repair.c b/passt-repair.c
index e0c366e..8bb3f00 100644
--- a/passt-repair.c
+++ b/passt-repair.c
@@ -16,11 +16,14 @@
* off. Reply by echoing the command. Exit on EOF.
*/
+#include <sys/inotify.h>
#include <sys/prctl.h>
#include <sys/types.h>
#include <sys/socket.h>
+#include <sys/stat.h>
#include <sys/un.h>
#include <errno.h>
+#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
@@ -39,6 +42,8 @@
#include "seccomp_repair.h"
#define SCM_MAX_FD 253 /* From Linux kernel (include/net/scm.h), not in UAPI */
+#define REPAIR_EXT ".repair"
+#define REPAIR_EXT_LEN strlen(REPAIR_EXT)
/**
* main() - Entry point and whole program with loop
@@ -51,6 +56,9 @@
* #syscalls:repair socket s390x:socketcall i686:socketcall
* #syscalls:repair recvfrom recvmsg arm:recv ppc64le:recv
* #syscalls:repair sendto sendmsg arm:send ppc64le:send
+ * #syscalls:repair stat|statx stat64|statx statx
+ * #syscalls:repair fstat|fstat64 newfstatat|fstatat64
+ * #syscalls:repair inotify_init1 inotify_add_watch
*/
int main(int argc, char **argv)
{
@@ -58,12 +66,14 @@ int main(int argc, char **argv)
__attribute__ ((aligned(__alignof__(struct cmsghdr))));
struct sockaddr_un a = { AF_UNIX, "" };
int fds[SCM_MAX_FD], s, ret, i, n = 0;
+ bool inotify_dir = false;
struct sock_fprog prog;
int8_t cmd = INT8_MAX;
struct cmsghdr *cmsg;
struct msghdr msg;
struct iovec iov;
size_t cmsg_len;
+ struct stat sb;
int op;
prctl(PR_SET_DUMPABLE, 0);
@@ -90,19 +100,77 @@ int main(int argc, char **argv)
_exit(2);
}
- ret = snprintf(a.sun_path, sizeof(a.sun_path), "%s", argv[1]);
- if (ret <= 0 || ret >= (int)sizeof(a.sun_path)) {
- fprintf(stderr, "Invalid socket path: %s\n", argv[1]);
- _exit(2);
- }
-
if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
fprintf(stderr, "Failed to create AF_UNIX socket: %i\n", errno);
_exit(1);
}
- if (connect(s, (struct sockaddr *)&a, sizeof(a))) {
- fprintf(stderr, "Failed to connect to %s: %s\n", argv[1],
+ if ((stat(argv[1], &sb))) {
+ fprintf(stderr, "Can't stat() %s: %i\n", argv[1], errno);
+ _exit(1);
+ }
+
+ if ((sb.st_mode & S_IFMT) == S_IFDIR) {
+ char buf[sizeof(struct inotify_event) + NAME_MAX + 1];
+ const struct inotify_event *ev;
+ char path[PATH_MAX + 1];
+ ssize_t n;
+ int fd;
+
+ ev = (struct inotify_event *)buf;
+
+ if ((fd = inotify_init1(IN_CLOEXEC)) < 0) {
+ fprintf(stderr, "inotify_init1: %i\n", errno);
+ _exit(1);
+ }
+
+ if (inotify_add_watch(fd, argv[1], IN_CREATE) < 0) {
+ fprintf(stderr, "inotify_add_watch: %i\n", errno);
+ _exit(1);
+ }
+
+ do {
+ n = read(fd, buf, sizeof(buf));
+ if (n < 0) {
+ fprintf(stderr, "inotify read: %i", errno);
+ _exit(1);
+ }
+
+ if (n < (ssize_t)sizeof(*ev)) {
+ fprintf(stderr, "Short inotify read: %zi", n);
+ _exit(1);
+ }
+ } while (ev->len < REPAIR_EXT_LEN ||
+ memcmp(ev->name + strlen(ev->name) - REPAIR_EXT_LEN,
+ REPAIR_EXT, REPAIR_EXT_LEN));
+
+ snprintf(path, sizeof(path), "%s/%s", argv[1], ev->name);
+ if ((stat(path, &sb))) {
+ fprintf(stderr, "Can't stat() %s: %i\n", path, errno);
+ _exit(1);
+ }
+
+ ret = snprintf(a.sun_path, sizeof(a.sun_path), path);
+ inotify_dir = true;
+ } else {
+ ret = snprintf(a.sun_path, sizeof(a.sun_path), "%s", argv[1]);
+ }
+
+ if (ret <= 0 || ret >= (int)sizeof(a.sun_path)) {
+ fprintf(stderr, "Invalid socket path");
+ _exit(2);
+ }
+
+ if ((sb.st_mode & S_IFMT) != S_IFSOCK) {
+ fprintf(stderr, "%s is not a socket\n", a.sun_path);
+ _exit(2);
+ }
+
+ while (connect(s, (struct sockaddr *)&a, sizeof(a))) {
+ if (inotify_dir && errno == ECONNREFUSED)
+ continue;
+
+ fprintf(stderr, "Failed to connect to %s: %s\n", a.sun_path,
strerror(errno));
_exit(1);
}