[dpdk-dev] [PATCH v2] example/ip_fragmentation: add fragmentation size support

[Ashish Jain <ashish.jain@nxp.com>]

Adding support for determining fragmentation size for both
ipv4 and ipv6 traffic dynamically through command line.
It is helpful in testing to configure different fragmentation
sizes and validate the packets.

Signed-off-by: Ashish Jain <ashish.jain@nxp.com>
Signed-off-by: Hemant Agrawal <hemant.agrawal@nxp.com>
---
Changes in v2:
* used strncmp while associating long options with short ones
* added detailed usage for new added params

 examples/ip_fragmentation/main.c | 96 ++++++++++++++++++++++++++++++++++++----
 1 file changed, 88 insertions(+), 8 deletions(-)

diff --git a/examples/ip_fragmentation/main.c b/examples/ip_fragmentation/main.c
index 2f45264..c0b36cd 100644
--- a/examples/ip_fragmentation/main.c
+++ b/examples/ip_fragmentation/main.c
@@ -95,6 +95,16 @@
 #define	IPV6_DEFAULT_PAYLOAD	(IPV6_MTU_DEFAULT - sizeof(struct ipv6_hdr))
 
 /*
+ * Configure fragmentation size for IPv4 and IPv6 packets
+ */
+static uint32_t frag_size_v4 = IPV4_MTU_DEFAULT;
+static uint32_t frag_size_v6 = IPV6_MTU_DEFAULT;
+#define MIN_IPV4_FRAG_SIZE 64
+#define MAX_IPV4_FRAG_SIZE 9600
+#define MIN_IPV6_FRAG_SIZE 1280
+#define MAX_IPV6_FRAG_SIZE 9600
+
+/*
  * Max number of fragments per packet expected - defined by config file.
  */
 #define	MAX_PACKET_FRAG RTE_LIBRTE_IP_FRAG_MAX_FRAG
@@ -139,6 +149,9 @@ static struct ether_addr ports_eth_addr[RTE_MAX_ETHPORTS];
 
 #define IPV6_ADDR_LEN 16
 
+#define CMD_LINE_OPT_IPV4_FRAG_SIZE "frag_size_v4"
+#define CMD_LINE_OPT_IPV6_FRAG_SIZE "frag_size_v6"
+
 /* mask of enabled ports */
 static int enabled_port_mask = 0;
 
@@ -300,14 +313,14 @@ l3fwd_simple_forward(struct rte_mbuf *m, struct lcore_queue_conf *qconf,
 		}
 
 		/* if we don't need to do any fragmentation */
-		if (likely (IPV4_MTU_DEFAULT >= m->pkt_len)) {
+		if (likely(frag_size_v4 >= m->pkt_len)) {
 			qconf->tx_mbufs[port_out].m_table[len] = m;
 			len2 = 1;
 		} else {
 			len2 = rte_ipv4_fragment_packet(m,
 				&qconf->tx_mbufs[port_out].m_table[len],
 				(uint16_t)(MBUF_TABLE_SIZE - len),
-				IPV4_MTU_DEFAULT,
+				frag_size_v4,
 				rxq->direct_pool, rxq->indirect_pool);
 
 			/* Free input packet */
@@ -336,14 +349,14 @@ l3fwd_simple_forward(struct rte_mbuf *m, struct lcore_queue_conf *qconf,
 		}
 
 		/* if we don't need to do any fragmentation */
-		if (likely (IPV6_MTU_DEFAULT >= m->pkt_len)) {
+		if (likely(frag_size_v6 >= m->pkt_len)) {
 			qconf->tx_mbufs[port_out].m_table[len] = m;
 			len2 = 1;
 		} else {
 			len2 = rte_ipv6_fragment_packet(m,
 				&qconf->tx_mbufs[port_out].m_table[len],
 				(uint16_t)(MBUF_TABLE_SIZE - len),
-				IPV6_MTU_DEFAULT,
+				frag_size_v6,
 				rxq->direct_pool, rxq->indirect_pool);
 
 			/* Free input packet */
@@ -489,8 +502,16 @@ print_usage(const char *prgname)
 {
 	printf("%s [EAL options] -- -p PORTMASK [-q NQ]\n"
 	       "  -p PORTMASK: hexadecimal bitmask of ports to configure\n"
-	       "  -q NQ: number of queue (=ports) per lcore (default is 1)\n",
-	       prgname);
+	       "  -q NQ: number of queue (=ports) per lcore (default is 1)\n"
+	       "  --frag_size_v4=<num>: optional,  IPv4 fragment size in decimal,\n"
+	       "\t Condition:(frag_size_v4 - 20) should be a multiple of 8\n"
+	       "\t Min value: %d , Max value: %d, default is %d \n"
+	       "  --frag_size_v6=<num>: optional,  IPv6 fragment size in decimal,\n"
+	       "\t Condition:(frag_size_v6 - 40) should be a multiple of 8\n"
+	       "\t Min value: %d , Max value: %d, default is %d \n",
+	       prgname, MIN_IPV4_FRAG_SIZE, MAX_IPV4_FRAG_SIZE,
+	       IPV4_MTU_DEFAULT, MIN_IPV6_FRAG_SIZE, MAX_IPV6_FRAG_SIZE,
+	       IPV6_MTU_DEFAULT);
 }
 
 static int
@@ -528,6 +549,29 @@ parse_nqueue(const char *q_arg)
 	return n;
 }
 
+static int
+parse_frag_size(const char *str, uint32_t min, uint32_t max,
+		uint8_t hdr_size, uint32_t *val)
+{
+	char *end;
+	uint64_t v;
+
+	/* parse decimal string */
+	errno = 0;
+	v = strtoul(str, &end, 10);
+	if (errno != 0 || *end != '\0')
+		return -EINVAL;
+
+	if (v < min || v > max)
+		return -EINVAL;
+
+	if ((v - hdr_size) % 8)
+		return -EINVAL;
+
+	*val = (uint32_t)v;
+	return 0;
+}
+
 /* Parse the argument given in the command line of the application */
 static int
 parse_args(int argc, char **argv)
@@ -537,6 +581,8 @@ parse_args(int argc, char **argv)
 	int option_index;
 	char *prgname = argv[0];
 	static struct option lgopts[] = {
+		{"frag_size_v4", 1, 0, 0},
+		{"frag_size_v6", 1, 0, 0},
 		{NULL, 0, 0, 0}
 	};
 
@@ -568,8 +614,42 @@ parse_args(int argc, char **argv)
 
 		/* long options */
 		case 0:
-			print_usage(prgname);
-			return -1;
+			if (!strncmp(lgopts[option_index].name,
+				CMD_LINE_OPT_IPV4_FRAG_SIZE,
+				sizeof(CMD_LINE_OPT_IPV4_FRAG_SIZE))) {
+				ret = parse_frag_size(optarg,
+						MIN_IPV4_FRAG_SIZE,
+						MAX_IPV4_FRAG_SIZE,
+						sizeof(struct ipv4_hdr),
+						&frag_size_v4);
+				if (ret) {
+					printf("invalid value: \"%s\" for "
+						"parameter %s\n",
+						optarg,
+						lgopts[option_index].name);
+					print_usage(prgname);
+					return ret;
+				}
+			}
+			if (!strncmp(lgopts[option_index].name,
+				CMD_LINE_OPT_IPV6_FRAG_SIZE,
+				sizeof(CMD_LINE_OPT_IPV6_FRAG_SIZE))) {
+				ret = parse_frag_size(optarg,
+						MIN_IPV6_FRAG_SIZE,
+						MAX_IPV6_FRAG_SIZE,
+						sizeof(struct ipv6_hdr),
+						&frag_size_v6);
+				if (ret) {
+					printf("invalid value: \"%s\" for "
+						"parameter %s\n",
+						optarg,
+						lgopts[option_index].name);
+					print_usage(prgname);
+					return ret;
+				}
+			}
+
+			break;
 
 		default:
 			print_usage(prgname);
-- 
2.7.4