util: add virGetUNIXSocketPath helper

When receiving multiple socket FDs from systemd, it is critical to know
what socket address each corresponds to so we can setup the right
protocols on each.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 9339c2c3259da6912f11caf958ddc6cfa86edbce..7404759f7fa51e1e2bcb66f749c025e13ee14d10 100644 (file)
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2980,6 +2980,7 @@ virGetListenFDs;
 virGetSelfLastChanged;
 virGetSystemPageSize;
 virGetSystemPageSizeKB;
+virGetUNIXSocketPath;
 virGetUnprivSGIOSysfsPath;
 virGetUserCacheDirectory;
 virGetUserConfigDirectory;

diff --git a/src/util/virutil.c b/src/util/virutil.c
index e9dbaf3d7ade938cd13c6aa16e3fd087d438d54e..8352e0f1f1ce71b59b2fb66e6653d76d4be02a58 100644 (file)
--- a/src/util/virutil.c
+++ b/src/util/virutil.c
@@ -68,6 +68,10 @@
 # include <shlobj.h>
 #endif
 
+#ifdef HAVE_SYS_UN_H
+# include <sys/un.h>
+#endif
+
 #include "c-ctype.h"
 #include "mgetgroups.h"
 #include "virerror.h"
@@ -1978,6 +1982,47 @@ virGetListenFDs(void)
 
 #endif /* WIN32 */
 
+#ifdef HAVE_SYS_UN_H
+char *virGetUNIXSocketPath(int fd)
+{
+    struct sockaddr_storage ss = { 0 };
+    struct sockaddr_un *un = (struct sockaddr_un *)&ss;
+    socklen_t len = sizeof(ss);
+    char *path;
+
+    if (getsockname(fd, (struct sockaddr *)&ss, &len) < 0) {
+        virReportSystemError(errno, _("Unable to get address of FD %d"), fd);
+        return NULL;
+    }
+
+    if (ss.ss_family != AF_UNIX) {
+        virReportSystemError(EINVAL, _("FD %d is not a UNIX socket, has af=%d"),
+                             fd, ss.ss_family);
+        return NULL;
+    }
+
+    if (un->sun_path[0] == '\0')
+        un->sun_path[0] = '@';
+
+    if (VIR_ALLOC_N(path, sizeof(un->sun_path) + 1) < 0)
+        return NULL;
+
+    memcpy(path, un->sun_path, sizeof(un->sun_path));
+    path[sizeof(un->sun_path)] = '\0';
+    return path;
+}
+
+#else /* HAVE_SYS_UN_H */
+
+char *virGetUNIXSocketPath(int fd)
+{
+    virReportSystemError(ENOSYS, "%s",
+                         _("UNIX sockets not supported on this platform");
+    return NULL;
+}
+
+#endif /* HAVE_SYS_UN_H */
+
 #ifndef WIN32
 long virGetSystemPageSize(void)
 {

diff --git a/src/util/virutil.h b/src/util/virutil.h
index 9381ad568200772c23975069bdaaf826bfd12127..be0f6b0ea855c75b792f452a7813186087c2c0be 100644 (file)
--- a/src/util/virutil.h
+++ b/src/util/virutil.h
@@ -207,6 +207,7 @@ verify((int)VIR_TRISTATE_BOOL_NO == (int)VIR_TRISTATE_SWITCH_OFF);
 verify((int)VIR_TRISTATE_BOOL_ABSENT == (int)VIR_TRISTATE_SWITCH_ABSENT);
 
 unsigned int virGetListenFDs(void);
+char *virGetUNIXSocketPath(int fd);
 
 long virGetSystemPageSize(void) ATTRIBUTE_NOINLINE;
 long virGetSystemPageSizeKB(void) ATTRIBUTE_NOINLINE;