X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=drivers%2Fnet%2Ftap%2Ftap_netlink.c;h=75af3404b03593fceeed140b60ababf3a490f99d;hb=25ae7f1a5d9d127a46f8d62d1d689f77a78138fd;hp=14bbbec754f67b9302a1c9ba6941370e156614a1;hpb=cc02c977189c46f0fa7de4e25f5f79c9a92cd052;p=dpdk.git

diff --git a/drivers/net/tap/tap_netlink.c b/drivers/net/tap/tap_netlink.c
index 14bbbec754..75af3404b0 100644
--- a/drivers/net/tap/tap_netlink.c
+++ b/drivers/net/tap/tap_netlink.c
@@ -9,12 +9,19 @@
 #include <string.h>
 #include <sys/socket.h>
 #include <unistd.h>
+#include <stdbool.h>
 
 #include <rte_malloc.h>
 #include <tap_netlink.h>
 #include <rte_random.h>
+
 #include "tap_log.h"
 
+/* Compatibility with glibc < 2.24 */
+#ifndef SOL_NETLINK
+#define SOL_NETLINK     270
+#endif
+
 /* Must be quite large to support dumping a huge list of QDISC or filters. */
 #define BUF_SIZE (32 * 1024) /* Size of the buffer to receive kernel messages */
 #define SNDBUF_SIZE 32768 /* Send buffer size for the netlink socket */
@@ -43,6 +50,9 @@ tap_nl_init(uint32_t nl_groups)
 		.nl_family = AF_NETLINK,
 		.nl_groups = nl_groups,
 	};
+#ifdef NETLINK_EXT_ACK
+	int one = 1;
+#endif
 
 	fd = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE);
 	if (fd < 0) {
@@ -59,6 +69,12 @@ tap_nl_init(uint32_t nl_groups)
 		close(fd);
 		return -1;
 	}
+
+#ifdef NETLINK_EXT_ACK
+	/* Ask for extended ACK response. on older kernel will ignore request. */
+	setsockopt(fd, SOL_NETLINK, NETLINK_EXT_ACK, &one, sizeof(one));
+#endif
+
 	if (bind(fd, (struct sockaddr *)&local, sizeof(local)) < 0) {
 		TAP_LOG(ERR, "Unable to bind to the netlink socket");
 		close(fd);
@@ -101,26 +117,17 @@ tap_nl_final(int nlsk_fd)
 int
 tap_nl_send(int nlsk_fd, struct nlmsghdr *nh)
 {
-	/* man 7 netlink EXAMPLE */
-	struct sockaddr_nl sa = {
-		.nl_family = AF_NETLINK,
-	};
-	struct iovec iov = {
-		.iov_base = nh,
-		.iov_len = nh->nlmsg_len,
-	};
-	struct msghdr msg = {
-		.msg_name = &sa,
-		.msg_namelen = sizeof(sa),
-		.msg_iov = &iov,
-		.msg_iovlen = 1,
-	};
 	int send_bytes;
 
 	nh->nlmsg_pid = 0; /* communication with the kernel uses pid 0 */
 	nh->nlmsg_seq = (uint32_t)rte_rand();
-	send_bytes = sendmsg(nlsk_fd, &msg, 0);
+
+retry:
+	send_bytes = send(nlsk_fd, nh, nh->nlmsg_len, 0);
 	if (send_bytes < 0) {
+		if (errno == EINTR)
+			goto retry;
+
 		TAP_LOG(ERR, "Failed to send netlink message: %s (%d)",
 			strerror(errno), errno);
 		return -1;
@@ -128,6 +135,74 @@ tap_nl_send(int nlsk_fd, struct nlmsghdr *nh)
 	return send_bytes;
 }
 
+#ifdef NETLINK_EXT_ACK
+static const struct nlattr *
+tap_nl_attr_first(const struct nlmsghdr *nh, size_t offset)
+{
+	return (const struct nlattr *)((const char *)nh + NLMSG_SPACE(offset));
+}
+
+static const struct nlattr *
+tap_nl_attr_next(const struct nlattr *attr)
+{
+	return (const struct nlattr *)((const char *)attr
+				       + NLMSG_ALIGN(attr->nla_len));
+}
+
+static bool
+tap_nl_attr_ok(const struct nlattr *attr, int len)
+{
+	if (len < (int)sizeof(struct nlattr))
+		return false; /* missing header */
+	if (attr->nla_len < sizeof(struct nlattr))
+		return false; /* attribute length should include itself */
+	if ((int)attr->nla_len  > len)
+		return false; /* attribute is truncated */
+	return true;
+}
+
+
+/* Decode extended errors from kernel */
+static void
+tap_nl_dump_ext_ack(const struct nlmsghdr *nh, const struct nlmsgerr *err)
+{
+	const struct nlattr *attr;
+	const char *tail = (const char *)nh + NLMSG_ALIGN(nh->nlmsg_len);
+	size_t hlen = sizeof(*err);
+
+	/* no TLVs, no extended response */
+	if (!(nh->nlmsg_flags & NLM_F_ACK_TLVS))
+		return;
+
+	if (!(nh->nlmsg_flags & NLM_F_CAPPED))
+		hlen += err->msg.nlmsg_len - NLMSG_HDRLEN;
+
+	for (attr = tap_nl_attr_first(nh, hlen);
+	     tap_nl_attr_ok(attr, tail - (const char *)attr);
+	     attr = tap_nl_attr_next(attr)) {
+		uint16_t type = attr->nla_type & NLA_TYPE_MASK;
+
+		if (type == NLMSGERR_ATTR_MSG) {
+			const char *msg = (const char *)attr
+				+ NLMSG_ALIGN(sizeof(*attr));
+
+			if (err->error)
+				TAP_LOG(ERR, "%s", msg);
+			else
+
+				TAP_LOG(WARNING, "%s", msg);
+			break;
+		}
+	}
+}
+#else
+/*
+ * External ACK support was added in Linux kernel 4.17
+ * on older kernels, just ignore that part of message
+ */
+#define tap_nl_dump_ext_ack(nh, err) do { } while (0)
+#endif
+
 /**
  * Check that the kernel sends an appropriate ACK in response
  * to an tap_nl_send().
@@ -161,36 +236,29 @@ tap_nl_recv_ack(int nlsk_fd)
 int
 tap_nl_recv(int nlsk_fd, int (*cb)(struct nlmsghdr *, void *arg), void *arg)
 {
-	/* man 7 netlink EXAMPLE */
-	struct sockaddr_nl sa;
 	char buf[BUF_SIZE];
-	struct iovec iov = {
-		.iov_base = buf,
-		.iov_len = sizeof(buf),
-	};
-	struct msghdr msg = {
-		.msg_name = &sa,
-		.msg_namelen = sizeof(sa),
-		.msg_iov = &iov,
-		/* One message at a time */
-		.msg_iovlen = 1,
-	};
 	int multipart = 0;
 	int ret = 0;
 
 	do {
 		struct nlmsghdr *nh;
-		int recv_bytes = 0;
+		int recv_bytes;
 
-		recv_bytes = recvmsg(nlsk_fd, &msg, 0);
-		if (recv_bytes < 0)
+retry:
+		recv_bytes = recv(nlsk_fd, buf, sizeof(buf), 0);
+		if (recv_bytes < 0) {
+			if (errno == EINTR)
+				goto retry;
 			return -1;
+		}
+
 		for (nh = (struct nlmsghdr *)buf;
 		     NLMSG_OK(nh, (unsigned int)recv_bytes);
 		     nh = NLMSG_NEXT(nh, recv_bytes)) {
 			if (nh->nlmsg_type == NLMSG_ERROR) {
 				struct nlmsgerr *err_data = NLMSG_DATA(nh);
 
+				tap_nl_dump_ext_ack(nh, err_data);
 				if (err_data->error < 0) {
 					errno = -err_data->error;
 					return -1;