support INADDR_ANY and binding to specific IP

apps/pingpong/README

 Ping host:
-    sudo ./pingpong -- -f ping
+    sudo ./pingpong -c ../../config.ini -f ping
 
 Pong host:
-    sudo ./pingpong -- -f pong
+    sudo ./pingpong -c ../../config.ini -f pong

config.ini

@@ -8,6 +8,7 @@ n_mem_channels=2
 
 [port0]
 mac_addr=68:05:ca:95:f8:ec
+ip_addr=172.31.100.2
 
 [port0_dst]
 mac_addr=68:05:ca:95:fa:64

udpdk/udpdk_args.c

@@ -2,6 +2,7 @@
 // Created by leoll2 on 10/6/20.
 // Copyright (c) 2020 Leonardo Lai. All rights reserved.
 //
+#include <arpa/inet.h>  // for inet_addr
 
 #include <rte_ether.h>
 
@@ -17,15 +18,19 @@ extern char *primary_argv[MAX_ARGC];
 extern char *secondary_argv[MAX_ARGC];
 static char *progname;
 
-static int parse_handler(void* configuration, const char* section, const char* name, const char* value)
-{
-    #define MATCH(s, n) strcmp(section, s) == 0 && strcmp(name, n) == 0
+static int parse_handler(void* configuration, const char* section, const char* name, const char* value) {
+#define MATCH(s, n) strcmp(section, s) == 0 && strcmp(name, n) == 0
     if (MATCH("port0", "mac_addr")) {
         if (rte_ether_unformat_addr(value, &config.src_mac_addr) < 0) {
             fprintf(stderr, "Can't parse MAC address: %s\n", value);
             return 0;
         }
-    } else if (MATCH("port0_dst", "mac_addr")) {
+    } else if (MATCH("port0", "ip_addr")) {
+        config.src_ip_addr.s_addr = inet_addr(value);
+        if (config.src_ip_addr.s_addr == (in_addr_t)(-1)) {
+            fprintf(stderr, "Can't parse IPv4 address: %s\n", value);
+        }
+    }else if (MATCH("port0_dst", "mac_addr")) {
         if (rte_ether_unformat_addr(value, &config.dst_mac_addr) < 0) {
             fprintf(stderr, "Can't parse MAC address: %s\n", value);
             return 0;

udpdk/udpdk_syscall.c

@@ -125,15 +125,21 @@ int udpdk_bind(int sockfd, const struct sockaddr *addr, socklen_t addrlen)
         return -1;
     }
 
-    // Mark the slot as bound
+    // Mark the slot as bound, and store the corresponding IP and port
     exch_zone_desc->slots[sockfd].bound = 1;
     exch_zone_desc->slots[sockfd].udp_port = (int)port;
+    if (addr_in->sin_addr.s_addr == INADDR_ANY) {
+        // If INADDR_ANY, use the address from the configuration file
+        exch_zone_desc->slots[sockfd].ip_addr = config.src_ip_addr;
+    } else {
+        // If the address is explicitly set, bind to that
+        exch_zone_desc->slots[sockfd].ip_addr = addr_in->sin_addr;
+    }
 
     // Insert in the hashtable (port, sock_id)
     htable_insert(udp_port_table, (int)port, sockfd);
     RTE_LOG(INFO, SYSCALL, "Binding port %d to sock_id %d\n", port, sockfd);
 
-    // TODO must bind the IP address too (if INADDR_ANY, pick one)
     return 0;
 }
 
@@ -195,8 +201,6 @@ ssize_t udpdk_sendto(int sockfd, const void *buf, size_t len, int flags,
     void *udp_data;
     const struct sockaddr_in *dest_addr_in = (struct sockaddr_in *)dest_addr;
 
-    static uint32_t src_ip_addr = RTE_IPV4(2, 100, 31, 172);           // TODO from bind (reversed for endianness)
-
     // Validate the arguments
     if (sendto_validate_args(sockfd, buf, len, flags, dest_addr, addrlen) < 0) {
         return -1;
@@ -238,7 +242,7 @@ ssize_t udpdk_sendto(int sockfd, const void *buf, size_t len, int flags,
     ip_hdr->time_to_live = IP_DEFTTL;
     ip_hdr->next_proto_id = IPPROTO_UDP;
     ip_hdr->packet_id = 0;
-    ip_hdr->src_addr = src_ip_addr;   // TODO this should be determined by bind()
+    ip_hdr->src_addr = exch_zone_desc->slots[sockfd].ip_addr.s_addr;
     ip_hdr->dst_addr = dest_addr_in->sin_addr.s_addr;
     ip_hdr->total_length = rte_cpu_to_be_16(len + sizeof(*ip_hdr) + sizeof(*udp_hdr));
     ip_hdr->hdr_checksum = rte_ipv4_cksum(ip_hdr);

udpdk/udpdk_types.h

@@ -16,6 +16,7 @@
 #include <rte_memory.h>
 #include <rte_memzone.h>
 
+#include <netinet/in.h>
 #include <stdlib.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -29,6 +30,7 @@ struct exch_slot_info {
     int bound;      // used by a socket that did 'bind'
     int sockfd;     // TODO redundant because it matches the slot index in this implementation
     int udp_port;   // UDP port associated to the socket (only if bound)
+    struct in_addr ip_addr;     // IPv4 address associated to the socket (only if bound)
 } __rte_cache_aligned;
 
 struct exch_zone_info {
@@ -46,6 +48,7 @@ struct exch_slot {
 typedef struct {
     struct rte_ether_addr src_mac_addr;
     struct rte_ether_addr dst_mac_addr;
+    struct in_addr src_ip_addr;
     char lcores_primary[MAX_ARG_LEN];
     char lcores_secondary[MAX_ARG_LEN];
     int n_mem_channels;