examples: rtnl_route_dump: add memory mapped netlink supportnl-mmap

Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 61 insertions, 6 deletions

diff --git a/examples/rtnl/rtnl-route-dump.c b/examples/rtnl/rtnl-route-dump.c
index a798515..2d8e19b 100644
--- a/examples/rtnl/rtnl-route-dump.c
+++ b/examples/rtnl/rtnl-route-dump.c
@@ -4,6 +4,8 @@
 #include <string.h>
 #include <unistd.h>
 #include <time.h>
+#include <poll.h>
+#include <errno.h>
 #include <arpa/inet.h>
 
 #include <libmnl/libmnl.h>
@@ -285,12 +287,34 @@ static int data_cb(const struct nlmsghdr *nlh, void *data)
 	return MNL_CB_OK;
 }
 
+static int mnl_socket_poll(struct mnl_socket *nl)
+{
+	struct pollfd pfds[1];
+
+	while (1) {
+		pfds[0].fd	= mnl_socket_get_fd(nl);
+		pfds[0].events	= POLLIN | POLLERR;
+		pfds[0].revents = 0;
+
+		if (poll(pfds, 1, -1) < 0 && errno != -EINTR)
+			return -1;
+
+		if (pfds[0].revents & POLLIN)
+			return 0;
+		if (pfds[0].revents & POLLERR)
+			return -1;
+	}
+}
+
 int main(int argc, char *argv[])
 {
 	struct mnl_socket *nl;
 	char buf[MNL_SOCKET_BUFFER_SIZE];
+	struct nl_mmap_hdr *hdr;
 	struct nlmsghdr *nlh;
 	struct rtmsg *rtm;
+	ssize_t len;
+	void *ptr;
 	int ret;
 	unsigned int seq, portid;
 
@@ -316,6 +340,11 @@ int main(int argc, char *argv[])
 		exit(EXIT_FAILURE);
 	}
 
+	if (mnl_socket_set_ring(nl, 0, 0) < 0) {
+		perror("mnl_socket_set_ring");
+		exit(EXIT_FAILURE);
+	}
+
 	if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
 		perror("mnl_socket_bind");
 		exit(EXIT_FAILURE);
@@ -327,13 +356,39 @@ int main(int argc, char *argv[])
 		exit(EXIT_FAILURE);
 	}
 
-	ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
-	while (ret > 0) {
-		ret = mnl_cb_run(buf, ret, seq, portid, data_cb, NULL);
-		if (ret <= MNL_CB_STOP)
-			break;
-		ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
+	while (1) {
+		ret = mnl_socket_poll(nl);
+		if (ret < 0) {
+			perror("mnl_socket_poll");
+			exit(EXIT_FAILURE);
+		}
+
+		while (1) {
+			hdr = mnl_socket_get_frame(nl, MNL_RING_RX);
+
+			if (hdr->nm_status == NL_MMAP_STATUS_VALID) {
+				ptr = (void *)hdr + NL_MMAP_HDRLEN;
+				len = hdr->nm_len;
+				if (len == 0)
+					goto next;
+			} else if (hdr->nm_status == NL_MMAP_STATUS_COPY) {
+				len = recv(mnl_socket_get_fd(nl),
+					   buf, sizeof(buf), MSG_DONTWAIT);
+				if (len <= 0)
+					break;
+				ptr = buf;
+			} else
+				break;
+
+			ret = mnl_cb_run(ptr, len, seq, portid, data_cb, NULL);
+			if (ret <= MNL_CB_STOP)
+				goto end;
+next:
+			hdr->nm_status = NL_MMAP_STATUS_UNUSED;
+			mnl_socket_advance_ring(nl, MNL_RING_RX);
+		}
 	}
+end:
 	if (ret == -1) {
 		perror("error");
 		exit(EXIT_FAILURE);