selftests/bpf: Add connect_to_addr_str helper

Similar to connect_to_addr() helper for connecting to a server with the
given sockaddr_storage type address, this patch adds a new helper named
connect_to_addr_str() for connecting to a server with the given string
type address "addr_str", together with its "family" and "port" as other
parameters of connect_to_addr_str().

In connect_to_addr_str(), the parameters "family", "addr_str" and "port"
are used to create a sockaddr_storage type address "addr" by invoking
make_sockaddr(). Then pass this "addr" together with "addrlen", "type"
and "opts" to connect_to_addr().

Suggested-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/647e82170831558dbde132a7a3d86df660dba2c4.1721282219.git.tanggeliang@kylinos.cn
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

tools/testing/selftests/bpf/network_helpers.c

@@ -300,6 +300,21 @@ int connect_to_addr(int type, const struct sockaddr_storage *addr, socklen_t add
 	return fd;
 }
 
+int connect_to_addr_str(int family, int type, const char *addr_str, __u16 port,
+			const struct network_helper_opts *opts)
+{
+	struct sockaddr_storage addr;
+	socklen_t addrlen;
+
+	if (!opts)
+		opts = &default_opts;
+
+	if (make_sockaddr(family, addr_str, port, &addr, &addrlen))
+		return -1;
+
+	return connect_to_addr(type, &addr, addrlen, opts);
+}
+
 int connect_to_fd_opts(int server_fd, const struct network_helper_opts *opts)
 {
 	struct sockaddr_storage addr;

tools/testing/selftests/bpf/network_helpers.h

@@ -69,6 +69,8 @@ int client_socket(int family, int type,
 		  const struct network_helper_opts *opts);
 int connect_to_addr(int type, const struct sockaddr_storage *addr, socklen_t len,
 		    const struct network_helper_opts *opts);
+int connect_to_addr_str(int family, int type, const char *addr_str, __u16 port,
+			const struct network_helper_opts *opts);
 int connect_to_fd(int server_fd, int timeout_ms);
 int connect_to_fd_opts(int server_fd, const struct network_helper_opts *opts);
 int connect_fd_to_fd(int client_fd, int server_fd, int timeout_ms);