kerndat: check if setsockopt IPV6_FREEBIND is supported

Signed-off-by: Pavel Tikhomirov <[email protected]>
duguhaotian · Apr 16, 2023 · f1c8d38 · f1c8d38
1 parent 14e8836
commit f1c8d38
Show file tree

Hide file tree

Showing 3 changed files with 43 additions and 0 deletions.
diff --git a/criu/cr-check.c b/criu/cr-check.c
@@ -1375,6 +1375,14 @@ static int check_openat2(void)
 	return 0;
 }
 
+static int check_ipv6_freebind(void)
+{
+	if (!kdat.has_ipv6_freebind)
+		return -1;
+
+	return 0;
+}
+
 static int (*chk_feature)(void);
 
 /*
@@ -1494,6 +1502,7 @@ int cr_check(void)
 		ret |= check_move_mount_set_group();
 		ret |= check_openat2();
 		ret |= check_ptrace_get_rseq_conf();
+		ret |= check_ipv6_freebind();
 
 		if (kdat.lsm == LSMTYPE__APPARMOR)
 			ret |= check_apparmor_stacking();
@@ -1614,6 +1623,7 @@ static struct feature_list feature_list[] = {
 	{ "move_mount_set_group", check_move_mount_set_group },
 	{ "openat2", check_openat2 },
 	{ "get_rseq_conf", check_ptrace_get_rseq_conf },
+	{ "ipv6_freebind", check_ipv6_freebind },
 	{ NULL, NULL },
 };
 

diff --git a/criu/include/kerndat.h b/criu/include/kerndat.h
@@ -84,6 +84,7 @@ struct kerndat_s {
 	bool has_rseq;
 	bool has_ptrace_get_rseq_conf;
 	struct __ptrace_rseq_configuration libc_rseq_conf;
+	bool has_ipv6_freebind;
 };
 
 extern struct kerndat_s kdat;

diff --git a/criu/kerndat.c b/criu/kerndat.c
@@ -1541,6 +1541,34 @@ static int kerndat_has_nftables_concat(void)
 #endif
 }
 
+#ifndef IPV6_FREEBIND
+#define IPV6_FREEBIND 78
+#endif
+
+static int kerndat_has_ipv6_freebind(void)
+{
+	int sk, val;
+
+	sk = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
+	if (sk == -1) {
+		pr_perror("Unable to create a ipv6 dgram socket");
+		return -1;
+	}
+
+	val = 1;
+	if (setsockopt(sk, SOL_IPV6, IPV6_FREEBIND, &val, sizeof(int)) == -1) {
+		if (errno == ENOPROTOOPT) {
+			kdat.has_ipv6_freebind = false;
+			return 0;
+		}
+		pr_perror("Unable to setsockopt ipv6_freebind");
+		return -1;
+	}
+
+	kdat.has_ipv6_freebind = true;
+	return 0;
+}
+
 /*
  * Some features depend on resource that can be dynamically changed
  * at the OS runtime. There are cases that we cannot determine the
@@ -1780,6 +1808,10 @@ int kerndat_init(void)
 		pr_err("kerndat_has_ptrace_get_rseq_conf failed when initializing kerndat.\n");
 		ret = -1;
 	}
+	if (!ret && (kerndat_has_ipv6_freebind() < 0)) {
+		pr_err("kerndat_has_ipv6_freebind failed when initializing kerndat.\n");
+		ret = -1;
+	}
 
 	kerndat_lsm();
 	kerndat_mmap_min_addr();