AF_XDP-interaction: cmdline options for MAC-addresses

Change Ethernet MAC in transmitted frames via cmdline options (-G|--tx-dmac) or (-H|--tx-smac) Based on suggestion from: Ong Boon Leong <boon.leong.ong@intel.com> https://lore.kernel.org/all/20211124091821.3916046-3-boon.leong.ong@intel.com/ Suggested-by: Ong Boon Leong <boon.leong.ong@intel.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
2024-05-06 15:54:53 +00:00 · 2021-12-14 13:52:27 +01:00
parent b71f7f8cac
commit f3d5d3ca93
3 changed files with 50 additions and 23 deletions
--- a/AF_XDP-interaction/af_xdp_user.c
+++ b/AF_XDP-interaction/af_xdp_user.c
@@ -291,6 +291,12 @@ static const struct option_wrapper long_options[] = {
 	{{"busy-poll",	 no_argument,		NULL, 'B' },
 	 "Enable socket prefer NAPI busy-poll mode (remember adjust sysctl too)"},

+	{{"tx-dmac",	 required_argument,	NULL, 'G' },
+	 "Dest MAC addr of TX frame in aa:bb:cc:dd:ee:ff format", "aa:bb:cc:dd:ee:ff"},
+
+	{{"tx-smac",	 required_argument,	NULL, 'H' },
+	 "Src MAC addr of TX frame in aa:bb:cc:dd:ee:ff format", "aa:bb:cc:dd:ee:ff"},
+
 	{{0, 0, NULL,  0 }, NULL, false}
 };

@@ -562,11 +568,9 @@ static inline void csum_replace2(__sum16 *sum, __be16 old, __be16 new)
 */
 static uint8_t base_pkt_data[FRAME_SIZE];

-static struct ether_addr opt_tx_smac =
-{{ 0x24, 0x5e, 0xbe, 0x57, 0xf1, 0x64 }};
-static struct ether_addr opt_tx_dmac =
-//{{ 0x00, 0x1b, 0x21, 0xbb, 0x9a, 0x82 }};
-{{ 0xbc, 0xee, 0x7b, 0xda, 0xc2, 0x62 }};
+/* Can be changed via cmdline options (-G|--tx-dmac) or (-H|--tx-smac) */
+static struct ether_addr default_tx_smac = {{ 0x24, 0x5e, 0xbe, 0x57, 0xf1, 0x64 }};
+static struct ether_addr default_tx_dmac = {{ 0xbc, 0xee, 0x7b, 0xda, 0xc2, 0x62 }};

 #define MIN_PKT_SIZE 64
 static uint16_t opt_pkt_size = MIN_PKT_SIZE;
@@ -580,11 +584,13 @@ static uint16_t opt_pkt_size = MIN_PKT_SIZE;
 #define UDP_PKT_SIZE		(IP_PKT_SIZE - sizeof(struct iphdr))
 #define UDP_PKT_DATA_SIZE	(UDP_PKT_SIZE - sizeof(struct udphdr))

-static void gen_eth_hdr(struct ethhdr *eth_hdr)
+static void gen_eth_hdr(struct config *cfg, struct ethhdr *eth_hdr)
 {
-	/* Ethernet header */
-	memcpy(eth_hdr->h_dest  , &opt_tx_dmac, ETH_ALEN);
-	memcpy(eth_hdr->h_source, &opt_tx_smac, ETH_ALEN);
+	/* Ethernet header:
+	 *  Can be changed via cmdline options (-G|--tx-dmac) or (-H|--tx-smac)
+	 */
+	memcpy(eth_hdr->h_dest  , &cfg->opt_tx_dmac, ETH_ALEN);
+	memcpy(eth_hdr->h_source, &cfg->opt_tx_smac, ETH_ALEN);
 	eth_hdr->h_proto = htons(ETH_P_IP);
 }

@@ -652,7 +658,7 @@ static void gen_udp_hdr(struct udphdr *udp_hdr, struct iphdr *ip_hdr)
 				  IPPROTO_UDP, (__u16 *)udp_hdr);
 }

-static void gen_base_pkt(uint8_t *pkt_ptr)
+static void gen_base_pkt(struct config *cfg, uint8_t *pkt_ptr)
 {
 	struct ethhdr *eth_hdr = (struct ethhdr *)pkt_ptr;
 	struct iphdr *ip_hdr = (struct iphdr *)(pkt_ptr +
@@ -661,7 +667,7 @@ static void gen_base_pkt(uint8_t *pkt_ptr)
 						   sizeof(struct ethhdr) +
 						   sizeof(struct iphdr));

-	gen_eth_hdr(eth_hdr);
+	gen_eth_hdr(cfg, eth_hdr);
 	gen_ip_hdr(ip_hdr);
 	gen_udp_hdr(udp_hdr, ip_hdr);
 }
@@ -823,7 +829,7 @@ static void print_pkt_info(uint8_t *pkt, uint32_t len)
 	}
 }

-static void tx_pkt(struct xsk_socket_info *xsk)
+static void tx_pkt(struct config *cfg, struct xsk_socket_info *xsk)
 {
 	struct xsk_umem_info *umem = xsk->umem;
 	uint64_t pkt_addr = mem_alloc_umem_frame(&umem->mem);
@@ -834,7 +840,7 @@ static void tx_pkt(struct xsk_socket_info *xsk)
 	pr_addr_info(__func__, pkt_addr, umem);

 	pkt = xsk_umem__get_data(umem->buffer, pkt_addr);
-	gen_base_pkt(pkt);
+	gen_base_pkt(cfg, pkt);

 	{
 		uint32_t tx_idx = 0;
@@ -857,7 +863,7 @@ static void tx_pkt(struct xsk_socket_info *xsk)
 /* Generate some fake packets (in umem area).  Real system will deliver TX
 * packets containing the needed control information.
 */
-static int invent_tx_pkts(struct xsk_umem_info *umem,
+static int invent_tx_pkts(struct config *cfg, struct xsk_umem_info *umem,
 			  const unsigned int n, struct xdp_desc pkts[n])
 {
 	uint32_t len = opt_pkt_size;
@@ -879,7 +885,7 @@ static int invent_tx_pkts(struct xsk_umem_info *umem,

 		/* Write into packet memory area */
 		pkt_data = xsk_umem__get_data(umem->buffer, pkt_addr);
-		gen_base_pkt(pkt_data);
+		gen_base_pkt(cfg, pkt_data);

 		pkts[i] = desc;
 	}
@@ -1173,8 +1179,8 @@ static void tx_cyclic_and_rx_process(struct config *cfg,
 	// Choosing xsk id 0
 	struct xsk_socket_info *xsk = xsks->sockets[0];

-	/* Get packets for first iteration */
-	tx_nr = invent_tx_pkts(xsk->umem, batch_nr, tx_pkts);
+	/* Get packets for *first* iteration */
+	tx_nr = invent_tx_pkts(cfg, xsk->umem, batch_nr, tx_pkts);

 	interval.tv_sec = period / USEC_PER_SEC;
 	interval.tv_nsec = (period % USEC_PER_SEC) * 1000;
@@ -1233,8 +1239,8 @@ static void tx_cyclic_and_rx_process(struct config *cfg,
 		next.tv_nsec += interval.tv_nsec;
 		tsnorm(&next);

-		/* Get packets for next iteration */
-		tx_nr = invent_tx_pkts(xsk->umem, batch_nr, tx_pkts);
+		/* Get packets for *next* iteration */
+		tx_nr = invent_tx_pkts(cfg, xsk->umem, batch_nr, tx_pkts);

 		/* Empty RX queues */
 		rx_avail_packets(xsks);
@@ -1366,6 +1372,8 @@ int main(int argc, char **argv)
 		.progsec = "xdp_sock",
 		.xsk_wakeup_mode = true, /* Default, change via --spin */
 		.xsk_if_queue = -1,
+		.opt_tx_dmac = default_tx_dmac,
+		.opt_tx_smac = default_tx_smac,
 	};
 	pthread_t stats_poll_thread;
 	struct xsk_umem_info *umem;
@@ -1484,7 +1492,7 @@ int main(int argc, char **argv)
 	}

 	/* Generate packets to TX */
-	gen_base_pkt((uint8_t*)&base_pkt_data);
+	gen_base_pkt(&cfg, (uint8_t*)&base_pkt_data);

 	/* Open and configure the AF_XDP (xsk) socket(s) */
 	for (i = 0; i < xsks.num; i++) {
@@ -1538,7 +1546,7 @@ int main(int argc, char **argv)
 	 * be initilized correctly?
 	 */
 	//sleep(3);
-	// tx_pkt(xsks.sockets[0]);
+	// tx_pkt(&cfg, xsks.sockets[0]);

 	/* Receive and count packets than drop them */
 	// rx_and_process(&cfg, &xsks);
--- a/AF_XDP-interaction/common_defines.h
+++ b/AF_XDP-interaction/common_defines.h
@@ -4,6 +4,7 @@
 #include <net/if.h>
 #include <linux/types.h>
 #include <stdbool.h>
+#include <netinet/ether.h> /* struct ether_addr */

 struct config {
 	__u32 xdp_flags;
@@ -27,6 +28,8 @@ struct config {
 	int sched_prio;
 	int sched_policy;
 	bool opt_busy_poll;
+	struct ether_addr opt_tx_smac;
+	struct ether_addr opt_tx_dmac;
 };

 /* Defined in common_params.o */
--- a/AF_XDP-interaction/common_params.c
+++ b/AF_XDP-interaction/common_params.c
@@ -29,7 +29,7 @@ void _print_options(const struct option_wrapper *long_options, bool required)
 		if (long_options[i].required != required)
 			continue;

-		if (long_options[i].option.val > 64) /* ord('A') = 65 */
+		if (long_options[i].option.val > 64) /* ord('A') = 65 = 0x41 */
 			printf(" -%c,", long_options[i].option.val);
 		else
 			printf("    ");
@@ -96,7 +96,7 @@ void parse_cmdline_args(int argc, char **argv,
 	}

 	/* Parse commands line args */
-	while ((opt = getopt_long(argc, argv, "hd:r:L:R:BASNFUMQ:czqp:",
+	while ((opt = getopt_long(argc, argv, "hd:r:L:R:BASNFUMQ:G:H:czqp:",
 				  long_options, &longindex)) != -1) {
 		switch (opt) {
 		case 'd':
@@ -129,6 +129,22 @@ void parse_cmdline_args(int argc, char **argv,
 				goto error;
 			}
 			break;
+		case 'G':
+			if (!ether_aton_r(optarg,
+					  (struct ether_addr *)&cfg->opt_tx_dmac)) {
+				fprintf(stderr, "Invalid dest MAC address:%s\n",
+					optarg);
+				goto error;
+			}
+			break;
+		case 'H':
+			if (!ether_aton_r(optarg,
+					  (struct ether_addr *)&cfg->opt_tx_smac)) {
+				fprintf(stderr, "Invalid src MAC address:%s\n",
+					optarg);
+				goto error;
+			}
+			break;
 		case 'B':
 			cfg->opt_busy_poll = true;
 			break;