New utility slirp_ether_ntoa

... and call it everywhere a macaddr is pretty-printed.

Signed-off-by: Doug Evans <dje@google.com>

5 files changed, 41 insertions, 19 deletions

diff --git a/src/arp_table.c b/src/arp_table.c
index 959e5b9..ba8c8a4 100644
--- a/src/arp_table.c
+++ b/src/arp_table.c
@@ -34,11 +34,12 @@ void arp_table_add(Slirp *slirp, uint32_t ip_addr,
         ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
     ArpTable *arptbl = &slirp->arp_table;
     int i;
+    char ethaddr_str[ETH_ADDRSTRLEN];
 
     DEBUG_CALL("arp_table_add");
     DEBUG_ARG("ip = %s", inet_ntoa((struct in_addr){ .s_addr = ip_addr }));
-    DEBUG_ARG("hw addr = %02x:%02x:%02x:%02x:%02x:%02x", ethaddr[0], ethaddr[1],
-              ethaddr[2], ethaddr[3], ethaddr[4], ethaddr[5]);
+    DEBUG_ARG("hw addr = %s", slirp_ether_ntoa(ethaddr, ethaddr_str,
+                                               sizeof(ethaddr_str)));
 
     if (ip_addr == 0 || ip_addr == 0xffffffff || ip_addr == broadcast_addr) {
         /* Do not register broadcast addresses */
@@ -67,6 +68,7 @@ bool arp_table_search(Slirp *slirp, uint32_t ip_addr,
         ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
     ArpTable *arptbl = &slirp->arp_table;
     int i;
+    char ethaddr_str[ETH_ADDRSTRLEN];
 
     DEBUG_CALL("arp_table_search");
     DEBUG_ARG("ip = %s", inet_ntoa((struct in_addr){ .s_addr = ip_addr }));
@@ -81,9 +83,9 @@ bool arp_table_search(Slirp *slirp, uint32_t ip_addr,
     for (i = 0; i < ARP_TABLE_SIZE; i++) {
         if (arptbl->table[i].ar_sip == ip_addr) {
             memcpy(out_ethaddr, arptbl->table[i].ar_sha, ETH_ALEN);
-            DEBUG_ARG("found hw addr = %02x:%02x:%02x:%02x:%02x:%02x",
-                      out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
-                      out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]);
+            DEBUG_ARG("found hw addr = %s",
+                      slirp_ether_ntoa(out_ethaddr, ethaddr_str,
+                                       sizeof(ethaddr_str)));
             return 1;
         }
     }
diff --git a/src/ndp_table.c b/src/ndp_table.c
index 110d6ea..61ae8e0 100644
--- a/src/ndp_table.c
+++ b/src/ndp_table.c
@@ -12,13 +12,14 @@ void ndp_table_add(Slirp *slirp, struct in6_addr ip_addr,
     char addrstr[INET6_ADDRSTRLEN];
     NdpTable *ndp_table = &slirp->ndp_table;
     int i;
+    char ethaddr_str[ETH_ADDRSTRLEN];
 
     inet_ntop(AF_INET6, &(ip_addr), addrstr, INET6_ADDRSTRLEN);
 
     DEBUG_CALL("ndp_table_add");
     DEBUG_ARG("ip = %s", addrstr);
-    DEBUG_ARG("hw addr = %02x:%02x:%02x:%02x:%02x:%02x", ethaddr[0], ethaddr[1],
-              ethaddr[2], ethaddr[3], ethaddr[4], ethaddr[5]);
+    DEBUG_ARG("hw addr = %s", slirp_ether_ntoa(ethaddr, ethaddr_str,
+                                               sizeof(ethaddr_str)));
 
     if (IN6_IS_ADDR_MULTICAST(&ip_addr) || in6_zero(&ip_addr)) {
         /* Do not register multicast or unspecified addresses */
@@ -50,6 +51,7 @@ bool ndp_table_search(Slirp *slirp, struct in6_addr ip_addr,
     char addrstr[INET6_ADDRSTRLEN];
     NdpTable *ndp_table = &slirp->ndp_table;
     int i;
+    char ethaddr_str[ETH_ADDRSTRLEN];
 
     inet_ntop(AF_INET6, &(ip_addr), addrstr, INET6_ADDRSTRLEN);
 
@@ -66,18 +68,18 @@ bool ndp_table_search(Slirp *slirp, struct in6_addr ip_addr,
         out_ethaddr[3] = ip_addr.s6_addr[13];
         out_ethaddr[4] = ip_addr.s6_addr[14];
         out_ethaddr[5] = ip_addr.s6_addr[15];
-        DEBUG_ARG("multicast addr = %02x:%02x:%02x:%02x:%02x:%02x",
-                  out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
-                  out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]);
+        DEBUG_ARG("multicast addr = %s",
+                  slirp_ether_ntoa(out_ethaddr, ethaddr_str,
+                                   sizeof(ethaddr_str)));
         return 1;
     }
 
     for (i = 0; i < NDP_TABLE_SIZE; i++) {
         if (in6_equal(&ndp_table->table[i].ip_addr, &ip_addr)) {
             memcpy(out_ethaddr, ndp_table->table[i].eth_addr, ETH_ALEN);
-            DEBUG_ARG("found hw addr = %02x:%02x:%02x:%02x:%02x:%02x",
-                      out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
-                      out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]);
+            DEBUG_ARG("found hw addr = %s",
+                      slirp_ether_ntoa(out_ethaddr, ethaddr_str,
+                                       sizeof(ethaddr_str)));
             return 1;
         }
     }
diff --git a/src/slirp.c b/src/slirp.c
index 79ba734..110e6fc 100644
--- a/src/slirp.c
+++ b/src/slirp.c
@@ -1060,6 +1060,7 @@ int if_encap(Slirp *slirp, struct mbuf *ifm)
     uint8_t ethaddr[ETH_ALEN];
     const struct ip *iph = (const struct ip *)ifm->m_data;
     int ret;
+    char ethaddr_str[ETH_ADDRSTRLEN];
 
     if (ifm->m_len + ETH_HLEN > sizeof(buf)) {
         return 1;
@@ -1085,12 +1086,10 @@ int if_encap(Slirp *slirp, struct mbuf *ifm)
     }
 
     memcpy(eh->h_dest, ethaddr, ETH_ALEN);
-    DEBUG_ARG("src = %02x:%02x:%02x:%02x:%02x:%02x", eh->h_source[0],
-              eh->h_source[1], eh->h_source[2], eh->h_source[3],
-              eh->h_source[4], eh->h_source[5]);
-    DEBUG_ARG("dst = %02x:%02x:%02x:%02x:%02x:%02x", eh->h_dest[0],
-              eh->h_dest[1], eh->h_dest[2], eh->h_dest[3], eh->h_dest[4],
-              eh->h_dest[5]);
+    DEBUG_ARG("src = %s", slirp_ether_ntoa(eh->h_source, ethaddr_str,
+                                           sizeof(ethaddr_str)));
+    DEBUG_ARG("dst = %s", slirp_ether_ntoa(eh->h_dest, ethaddr_str,
+                                           sizeof(ethaddr_str)));
     memcpy(buf + sizeof(struct ethhdr), ifm->m_data, ifm->m_len);
     slirp_send_packet_all(slirp, buf, ifm->m_len + ETH_HLEN);
     return 1;
diff --git a/src/util.c b/src/util.c
index 2d8fb96..67ef667 100644
--- a/src/util.c
+++ b/src/util.c
@@ -427,3 +427,14 @@ int slirp_fmt0(char *str, size_t size, const char *format, ...)
 
     return rv;
 }
+
+const char *slirp_ether_ntoa(const uint8_t *addr, char *out_str,
+                             size_t out_str_size)
+{
+    assert(out_str_size >= ETH_ADDRSTRLEN);
+
+    slirp_fmt0(out_str, out_str_size, "%02x:%02x:%02x:%02x:%02x:%02x",
+               addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
+
+    return out_str;
+}
diff --git a/src/util.h b/src/util.h
index d67b3d0..8134db9 100644
--- a/src/util.h
+++ b/src/util.h
@@ -84,6 +84,7 @@ struct iovec {
 #define SCALE_MS 1000000
 
 #define ETH_ALEN 6
+#define ETH_ADDRSTRLEN 18 /* "xx:xx:xx:xx:xx:xx", with trailing NUL */
 #define ETH_HLEN 14
 #define ETH_P_IP (0x0800) /* Internet Protocol packet  */
 #define ETH_P_ARP (0x0806) /* Address Resolution packet */
@@ -186,4 +187,11 @@ void slirp_pstrcpy(char *buf, int buf_size, const char *str);
 int slirp_fmt(char *str, size_t size, const char *format, ...) G_GNUC_PRINTF(3, 4);
 int slirp_fmt0(char *str, size_t size, const char *format, ...) G_GNUC_PRINTF(3, 4);
 
+/*
+ * Pretty print a MAC address into out_str.
+ * As a convenience returns out_str.
+ */
+const char *slirp_ether_ntoa(const uint8_t *addr, char *out_str,
+                             size_t out_str_len);
+
 #endif