feat: set TOS

includes/icmp.h

@@ -76,6 +76,7 @@ int icmp_error_extract_offending(const icmp_reply_t *reply,
 
 /* Socket options */
 int icmp_set_dont_fragment(icmp_handle_t *h);
+int icmp_set_tos(icmp_handle_t *h, uint8_t tos);
 
 /* Error handling */
 const char *icmp_strerror(const icmp_handle_t *h);

sources.mk

@@ -9,6 +9,7 @@ SRCS += $(SRC_DIR)/error/should_retry.c
 SRCS += $(SRC_DIR)/socket/create.c
 SRCS += $(SRC_DIR)/socket/configure.c
 SRCS += $(SRC_DIR)/socket/set_dont_fragment.c
+SRCS += $(SRC_DIR)/socket/set_tos.c
 SRCS += $(SRC_DIR)/handle/create.c
 SRCS += $(SRC_DIR)/handle/destroy.c
 SRCS += $(SRC_DIR)/handle/get_fd.c

src/socket/set_tos.c

@@ -0,0 +1,25 @@
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <errno.h>
+#include <string.h>
+
+#include "internal/icmp_internal.h"
+
+int
+icmp_set_tos(struct icmp_handle *h, uint8_t tos)
+{
+	int	val;
+	int	saved_errno;
+
+	if (NULL == h)
+		return -1;
+	val = (int)tos;
+	if (0 > setsockopt(h->fd, IPPROTO_IP, IP_TOS, &val, sizeof(val)))
+	{
+		saved_errno = errno;
+		icmp_set_error_fmt(h, ICMP_ERR_SOCKET,
+				"Failed to set TOS: %s", strerror(saved_errno));
+		return -1;
+	}
+	return 0;
+}