[PATCH v8 03/14] tap, conf: Replace addr_fixed with CONF_ADDR_USER flag check

[Jon Maloy <jmaloy@redhat.com>]

The addr_fixed boolean (per address family) was introduced to prevent
observed traffic from overwriting addr_seen when the user explicitly
set an address with -a/--address.

The unified address array already tracks this: fwd_set_addr() marks
user-provided addresses with CONF_ADDR_USER. We now replace all
addr_fixed checks with fwd_get_addr() lookups for CONF_ADDR_USER
and remove the now-redundant field from ip4_ctx and ip6_ctx.

Signed-off-by: Jon Maloy <jmaloy@redhat.com>
---
 conf.c  | 7 ++-----
 passt.h | 6 ------
 tap.c   | 9 ++++-----
 3 files changed, 6 insertions(+), 16 deletions(-)

diff --git a/conf.c b/conf.c
index ac8facc8..1c0c1786 100644
--- a/conf.c
+++ b/conf.c
@@ -1598,13 +1598,10 @@ void conf(struct ctx *c, int argc, char **argv)
 
 			/* Legacy behaviour: replace existing address if any */
 			fwd_set_addr(c, &addr, CONF_ADDR_USER, prefix_len);
-			if (inany_v4(&addr)) {
+			if (inany_v4(&addr))
 				c->ip4.no_copy_addrs = true;
-				c->ip4.addr_fixed = true;
-			} else {
+			else
 				c->ip6.no_copy_addrs = true;
-				c->ip6.addr_fixed = true;
-			}
 			break;
 		}
 		case 'n': {
diff --git a/passt.h b/passt.h
index cafa35ea..11ccff05 100644
--- a/passt.h
+++ b/passt.h
@@ -100,8 +100,6 @@ struct guest_addr {
  * @ifname_out:		Optional interface name to bind outbound sockets to
  * @no_copy_routes:	Don't copy all routes when configuring target namespace
  * @no_copy_addrs:	Don't copy all addresses when configuring namespace
- * @addr_fixed:		Address was given explicitly (-a): don't update
- *			addr_seen from traffic observed on tap
  */
 struct ip4_ctx {
 	/* PIF_TAP addresses */
@@ -121,7 +119,6 @@ struct ip4_ctx {
 
 	bool no_copy_routes;
 	bool no_copy_addrs;
-	bool addr_fixed;
 };
 
 /**
@@ -141,8 +138,6 @@ struct ip4_ctx {
  * @ifname_out:		Optional interface name to bind outbound sockets to
  * @no_copy_routes:	Don't copy all routes when configuring target namespace
  * @no_copy_addrs:	Don't copy all addresses when configuring namespace
- * @addr_fixed:		Address was given explicitly (-a): don't update
- *			addr_seen from traffic observed on tap
  */
 struct ip6_ctx {
 	/* PIF_TAP addresses */
@@ -163,7 +158,6 @@ struct ip6_ctx {
 
 	bool no_copy_routes;
 	bool no_copy_addrs;
-	bool addr_fixed;
 };
 
 #include <netinet/if_ether.h>
diff --git a/tap.c b/tap.c
index 12630f58..573a3f10 100644
--- a/tap.c
+++ b/tap.c
@@ -756,7 +756,7 @@ resume:
 			continue;
 		}
 
-		if (!c->ip4.addr_fixed &&
+		if (!fwd_get_addr(c, AF_INET, CONF_ADDR_USER, 0) &&
 		    iph->saddr && c->ip4.addr_seen.s_addr != iph->saddr)
 			c->ip4.addr_seen.s_addr = iph->saddr;
 
@@ -1000,18 +1000,17 @@ resume:
 		if (IN6_IS_ADDR_LINKLOCAL(saddr)) {
 			c->ip6.addr_ll_seen = *saddr;
 
-			if (!c->ip6.addr_fixed &&
+			if (!fwd_get_addr(c, AF_INET6, CONF_ADDR_USER, 0) &&
 			    IN6_IS_ADDR_UNSPECIFIED(&c->ip6.addr_seen)) {
 				c->ip6.addr_seen = *saddr;
 			}
 
-			if (!c->ip6.addr_fixed &&
-			    !fwd_get_addr(c, AF_INET6, CONF_ADDR_ANY, 0)) {
+			if (!fwd_get_addr(c, AF_INET6, CONF_ADDR_USER, 0)) {
 				union inany_addr addr = { .a6 = *saddr };
 
 				fwd_set_addr(c, &addr, CONF_ADDR_LINKLOCAL, 64);
 			}
-		} else if (!c->ip6.addr_fixed &&
+		} else if (!fwd_get_addr(c, AF_INET6, CONF_ADDR_USER, 0) &&
 			   !IN6_IS_ADDR_UNSPECIFIED(saddr)) {
 			c->ip6.addr_seen = *saddr;
 		}
-- 
2.52.0