[systemd-devel] [PATCH 08/11] libsystemd-dhcp: Add functions for sending unicast UDP messages

[Patrik Flykt]

Create a helper functions setting up an unicast DHCP UDP socket and
sending data. Add function stubs for the test program.
---
 src/libsystemd-dhcp/dhcp-internal.h    |    3 +++
 src/libsystemd-dhcp/dhcp-network.c     |   38 ++++++++++++++++++++++++++++++++
 src/libsystemd-dhcp/test-dhcp-client.c |   11 +++++++++
 3 files changed, 52 insertions(+)

diff --git a/src/libsystemd-dhcp/dhcp-internal.h b/src/libsystemd-dhcp/dhcp-internal.h
index 4472d95..43b5b1d 100644
--- a/src/libsystemd-dhcp/dhcp-internal.h
+++ b/src/libsystemd-dhcp/dhcp-internal.h
@@ -29,8 +29,11 @@
 #include "dhcp-protocol.h"
 
 int dhcp_network_bind_raw_socket(int index, union sockaddr_union *link);
+int dhcp_network_bind_udp_socket(int index, be32_t client_address);
 int dhcp_network_send_raw_socket(int s, const union sockaddr_union *link,
                                  const void *packet, size_t len);
+int dhcp_network_send_udp_socket(int s, be32_t server_address,
+                                 const void *packet, size_t len);
 
 int dhcp_option_append(uint8_t **buf, size_t *buflen, uint8_t code,
                        size_t optlen, const void *optval);
diff --git a/src/libsystemd-dhcp/dhcp-network.c b/src/libsystemd-dhcp/dhcp-network.c
index 3ff2d0b..89350ca 100644
--- a/src/libsystemd-dhcp/dhcp-network.c
+++ b/src/libsystemd-dhcp/dhcp-network.c
@@ -54,6 +54,28 @@ int dhcp_network_bind_raw_socket(int index, union sockaddr_union *link)
         return s;
 }
 
+int dhcp_network_bind_udp_socket(int index, be32_t client_address)
+{
+        int s, err;
+        union sockaddr_union src = {};
+
+        s = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
+        if (s < 0)
+                return -errno;
+
+        src.in.sin_family = AF_INET;
+        src.in.sin_port = htobe16(DHCP_PORT_CLIENT);
+        src.in.sin_addr.s_addr = client_address;
+
+        if (bind(s, &src.sa, sizeof(src.in)) < 0) {
+                err = -errno;
+                close(s);
+                return err;
+        }
+
+        return s;
+}
+
 int dhcp_network_send_raw_socket(int s, const union sockaddr_union *link,
                                  const void *packet, size_t len)
 {
@@ -64,3 +86,19 @@ int dhcp_network_send_raw_socket(int s, const union sockaddr_union *link,
 
         return err;
 }
+
+int dhcp_network_send_udp_socket(int s, be32_t server_address,
+                                 const void *packet, size_t len)
+{
+        int err = 0;
+        union sockaddr_union dest = {};
+
+        dest.in.sin_family = AF_INET;
+        dest.in.sin_port = htobe16(DHCP_PORT_SERVER);
+        dest.in.sin_addr.s_addr = server_address;
+
+        if (sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in)) < 0)
+                err = -errno;
+
+        return err;
+}
diff --git a/src/libsystemd-dhcp/test-dhcp-client.c b/src/libsystemd-dhcp/test-dhcp-client.c
index 1ff78c1..617236b 100644
--- a/src/libsystemd-dhcp/test-dhcp-client.c
+++ b/src/libsystemd-dhcp/test-dhcp-client.c
@@ -184,6 +184,17 @@ int dhcp_network_bind_raw_socket(int index, union sockaddr_union *link)
         return test_fd[0];
 }
 
+int dhcp_network_bind_udp_socket(int index, be32_t client_address)
+{
+        return 0;
+}
+
+int dhcp_network_send_udp_socket(int s, be32_t server_address,
+                                 const void *packet, size_t len)
+{
+        return 0;
+}
+
 static void test_discover_message(sd_event *e)
 {
         sd_dhcp_client *client;
-- 
1.7.10.4