[PATCH v6 05/13] conf: Allow multiple -a/--address options per address family

[Jon Maloy <jmaloy@redhat.com>]

Allow specifying multiple addresses per family with -a/--address.
The first address of each family is used for DHCP/DHCPv6 assignment.

Signed-off-by: Jon Maloy <jmaloy@redhat.com>

---
v2: - Adapted to previous code changes
v3: - Adapted to single-array strategy
    - Changes according to feedback from S. Brivio and G Gibson.
v4: - Stripped down and adapted after feedback from David G.
v6: - Adapted to previous changes in series
    - Removed the "one address" limitation for -n option
---
 conf.c  |  7 ++++---
 fwd.c   |  7 ++-----
 pasta.c | 17 ++++++++++-------
 3 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/conf.c b/conf.c
index 8f02494..95f09cb 100644
--- a/conf.c
+++ b/conf.c
@@ -935,9 +935,11 @@ static void usage(const char *name, FILE *f, int status)
 		"    default: 65520: maximum 802.3 MTU minus 802.3 header\n"
 		"                    length, rounded to 32 bits (IPv4 words)\n"
 		"  -a, --address ADDR	Assign IPv4 or IPv6 address ADDR[/PREFIXLEN]\n"
-		"    can be specified zero to two times (for IPv4 and IPv6)\n"
+		"    can be specified up to a maximum of %d times\n"
 		"    default: use addresses from interface with default route\n"
-		"  -n, --netmask MASK	Assign IPv4 MASK, dot-decimal or bits\n"
+		"  -n, --netmask MASK	Assign IPv4 MASK, dot-decimal or bits\n",
+		MAX_GUEST_ADDRS);
+	FPRINTF(f,
 		"    default: netmask from matching address on the host\n"
 		"  -M, --mac-addr ADDR	Use source MAC address ADDR\n"
 		"    default: 9a:55:9a:55:9a:55 (locally administered)\n"
@@ -1891,7 +1893,6 @@ void conf(struct ctx *c, int argc, char **argv)
 			    IN6_IS_ADDR_V4COMPAT(&addr.a6))
 				die("Invalid address: %s", optarg);
 
-			/* Legacy behaviour: replace existing address if any */
 			fwd_set_addr(c, &addr, CONF_ADDR_USER, prefix_len);
 			if (inany_v4(&addr))
 				c->ip4.no_copy_addrs = true;
diff --git a/fwd.c b/fwd.c
index 695b5a5..2853c0e 100644
--- a/fwd.c
+++ b/fwd.c
@@ -250,14 +250,12 @@ void fwd_neigh_table_init(const struct ctx *c)
 }
 
 /**
- * fwd_set_addr() - Add or update an address in the unified address array
+ * fwd_set_addr() - Update address entry, adding one if needed
  * @c:		Execution context
  * @addr:	Address to add (IPv4-mapped or IPv6)
  * @flags:	CONF_ADDR_* flags for this address
  * @prefix_len:	Prefix length in IPv6/mapped format, 0-128
  *
- * Find the first existing entry of the same address family and
- * overwrite it, or create a new one if none exists
  */
 void fwd_set_addr(struct ctx *c, const union inany_addr *addr,
 		  uint8_t flags, int prefix_len)
@@ -266,8 +264,7 @@ void fwd_set_addr(struct ctx *c, const union inany_addr *addr,
 
 	for (int i = 0; i < c->addr_count; i++) {
 		a = &c->addrs[i];
-		if ((inany_v4(addr) && inany_v4(&a->addr)) ||
-		    (!inany_v4(addr) && !inany_v4(&a->addr)))
+		if (inany_equals(addr, &a->addr))
 			goto found;
 	}
 
diff --git a/pasta.c b/pasta.c
index e88a893..6307c65 100644
--- a/pasta.c
+++ b/pasta.c
@@ -342,12 +342,14 @@ void pasta_ns_conf(struct ctx *c)
 
 		if (c->ifi4) {
 			if (c->ip4.no_copy_addrs) {
-				a = fwd_get_addr(c, AF_INET, 0, 0);
-				if (a)
+				for_each_addr(a, c, AF_INET) {
 					rc = nl_addr_set(nl_sock_ns,
 							 c->pasta_ifi, AF_INET,
 							 inany_v4(&a->addr),
-							 a->prefix_len - 96);
+							 inany_prefix_len(a));
+					if (rc < 0)
+						break;
+				}
 			} else {
 				rc = nl_addr_dup(nl_sock, c->ifi4,
 						 nl_sock_ns, c->pasta_ifi,
@@ -400,13 +402,14 @@ ipv4_done:
 					  0, IFF_NOARP);
 
 			if (c->ip6.no_copy_addrs) {
-				a = fwd_get_addr(c, AF_INET6, 0, 0);
-				if (a)
+				for_each_addr(a, c, AF_INET6) {
 					rc = nl_addr_set(nl_sock_ns,
 							 c->pasta_ifi,
-							 AF_INET6,
-							 &a->addr.a6,
+							 AF_INET6, &a->addr.a6,
 							 a->prefix_len);
+					if (rc < 0)
+						break;
+				}
 			} else {
 				rc = nl_addr_dup(nl_sock, c->ifi6,
 						 nl_sock_ns, c->pasta_ifi,
-- 
2.52.0