1 files changed, 129 insertions, 0 deletions
diff --git a/src/libknot/xdp/eth.c b/src/libknot/xdp/eth.c
new file mode 100644
index 0000000..b3614b6
--- /dev/null
+++ b/src/libknot/xdp/eth.c
@@ -0,0 +1,129 @@
+/*  Copyright (C) 2020 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <bpf/libbpf.h>
+#include <errno.h>
+#include <ifaddrs.h>
+#include <linux/ethtool.h>
+#include <linux/if.h>
+#include <linux/if_link.h>
+#include <linux/sockios.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+#include "contrib/openbsd/strlcpy.h"
+#include "contrib/sockaddr.h"
+#include "libknot/attribute.h"
+#include "libknot/errcode.h"
+#include "libknot/xdp/eth.h"
+
+_public_
+int knot_eth_queues(const char *devname)
+{
+	if (devname == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	int fd = socket(AF_INET, SOCK_DGRAM, 0);
+	if (fd < 0) {
+		return knot_map_errno();
+	}
+
+	struct ethtool_channels ch = {
+		.cmd = ETHTOOL_GCHANNELS
+	};
+	struct ifreq ifr = {
+		.ifr_data = &ch
+	};
+	strlcpy(ifr.ifr_name, devname, IFNAMSIZ);
+
+	int ret = ioctl(fd, SIOCETHTOOL, &ifr);
+	if (ret != 0) {
+		if (errno == EOPNOTSUPP) {
+			ret = 1;
+		} else {
+			ret = knot_map_errno();
+		}
+	} else {
+		if (ch.combined_count == 0) {
+			ret = 1;
+		} else {
+			ret = ch.combined_count;
+		}
+	}
+
+	close(fd);
+	return ret;
+}
+
+_public_
+int knot_eth_name_from_addr(const struct sockaddr_storage *addr, char *out,
+                            size_t out_len)
+{
+	if (addr == NULL || out == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	struct ifaddrs *ifaces = NULL;
+	if (getifaddrs(&ifaces) != 0) {
+		return -errno;
+	}
+
+	size_t matches = 0;
+	char *match_name = NULL;
+
+	for (struct ifaddrs *ifa = ifaces; ifa != NULL; ifa = ifa->ifa_next) {
+		const struct sockaddr_storage *ifss = (struct sockaddr_storage *)ifa->ifa_addr;
+		if (ifss == NULL) { // Observed on interfaces without any address.
+			continue;
+		}
+
+		if ((ifss->ss_family == addr->ss_family && sockaddr_is_any(addr)) ||
+		    sockaddr_cmp(ifss, addr, true) == 0) {
+			matches++;
+			match_name = ifa->ifa_name;
+		}
+	}
+
+	if (matches == 1) {
+		size_t len = strlcpy(out, match_name, out_len);
+		freeifaddrs(ifaces);
+		return (len >= out_len) ? KNOT_ESPACE : KNOT_EOK;
+	}
+
+	freeifaddrs(ifaces);
+	return matches == 0 ? KNOT_EADDRNOTAVAIL : KNOT_ELIMIT;
+}
+
+_public_
+knot_xdp_mode_t knot_eth_xdp_mode(int if_index)
+{
+	struct xdp_link_info info;
+	int ret = bpf_get_link_xdp_info(if_index, &info, sizeof(info), 0);
+	if (ret != 0) {
+		return KNOT_XDP_MODE_NONE;
+	}
+
+	switch (info.attach_mode) {
+	case XDP_ATTACHED_DRV:
+	case XDP_ATTACHED_HW:
+		return KNOT_XDP_MODE_FULL;
+	case XDP_ATTACHED_SKB:
+		return KNOT_XDP_MODE_EMUL;
+	default:
+		return KNOT_XDP_MODE_NONE;
+	}
+}