Extract address and route configuration into two new helper functions
pasta_conf_addrs() and pasta_conf_routes(), and replace the outer
if (c->pasta_conf_ns) block with an early return. This reduces
indentation and eliminates the goto labels.
No functional change.
Signed-off-by: Jon Maloy
---
v7: -Removed redundant argument 'af' in nl_addr_set()
-Removed redundant label and 'goto's in pasta_ns_conf()
-Since I excluded addition of all LINKLOCAL addresses from host
address array in a previous commit I can now omit this test
in pasta_conf_addrs() as suggested by David.
-Here is the example of agnostic usage of inany_prefix_len()
I referred to in a previous commit.
v8: -Do prefix_len conversion inside nl_addr_set() instead of in
the calling function.
-In nl_addr_set(), branch on inany_prefix_v4() return value instead
of inany_af() to avoid redundant AF check and potential static
checker false positives. (David)
-Swap branch order in pasta_conf_routes() for consistency with
pasta_conf_addrs(). (David)
-Defer investigation of pre-existing IFF_NOARP / DAD interaction
oddity noted by David.
v9: - Broke out as standalone from multi-addr series.
- Adapted to code conditions before the introduction of
the unified address type.
v10: - Applied all suggestions from David, more for symmetry reasons
than for logical correctess.
---
pasta.c | 220 +++++++++++++++++++++++++++++---------------------------
1 file changed, 115 insertions(+), 105 deletions(-)
diff --git a/pasta.c b/pasta.c
index 4e7ee542..3401fda2 100644
--- a/pasta.c
+++ b/pasta.c
@@ -303,13 +303,70 @@ void pasta_start_ns(struct ctx *c, uid_t uid, gid_t gid,
die_perror("Failed to join network namespace");
}
+/**
+ * pasta_conf_addrs() - Configure addresses for one address family in namespace
+ * @c: Execution context
+ * @af: Address family (AF_INET or AF_INET6)
+ * @ifi: Host interface index for this address family
+ * @no_copy: If true, set configured address; if false, copy from host
+ *
+ * Return: 0 on success, negative error code on failure
+ */
+static int pasta_conf_addrs(struct ctx *c, sa_family_t af, int ifi,
+ bool no_copy)
+{
+ if (!ifi)
+ return 0;
+
+ if (!no_copy)
+ return nl_addr_dup(nl_sock, ifi, nl_sock_ns, c->pasta_ifi, af);
+
+ if (af == AF_INET && !IN4_IS_ADDR_UNSPECIFIED(&c->ip4.addr)) {
+ return nl_addr_set(nl_sock_ns, c->pasta_ifi, AF_INET,
+ &c->ip4.addr, c->ip4.prefix_len);
+ } else if (af == AF_INET6 && !IN6_IS_ADDR_UNSPECIFIED(&c->ip6.addr)) {
+ return nl_addr_set(nl_sock_ns, c->pasta_ifi, AF_INET6,
+ &c->ip6.addr, 64);
+ }
+ return 0;
+}
+
+/**
+ * pasta_conf_routes() - Configure routes for one address family in namespace
+ * @c: Execution context
+ * @af: Address family (AF_INET or AF_INET6)
+ * @ifi: Host interface index for this address family
+ * @no_copy: If true, set default route; if false, copy routes from host
+ *
+ * Return: 0 on success, negative error code on failure
+ */
+static int pasta_conf_routes(struct ctx *c, sa_family_t af, int ifi,
+ bool no_copy)
+{
+ const void *gw;
+
+ if (af == AF_INET)
+ gw = &c->ip4.guest_gw;
+ else
+ gw = &c->ip6.guest_gw;
+
+ if (!ifi)
+ return 0;
+
+ if (!no_copy)
+ return nl_route_dup(nl_sock, ifi, nl_sock_ns, c->pasta_ifi, af);
+
+ return nl_route_set_def(nl_sock_ns, c->pasta_ifi, af, gw);
+}
+
/**
* pasta_ns_conf() - Set up loopback and tap interfaces in namespace as needed
* @c: Execution context
*/
void pasta_ns_conf(struct ctx *c)
{
- int rc = 0;
+ unsigned int flags = IFF_UP;
+ int rc;
rc = nl_link_set_flags(nl_sock_ns, 1 /* lo */, IFF_UP, IFF_UP);
if (rc < 0)
@@ -328,116 +385,69 @@ void pasta_ns_conf(struct ctx *c)
die("Couldn't set MAC address in namespace: %s",
strerror_(-rc));
- if (c->pasta_conf_ns) {
- unsigned int flags = IFF_UP;
-
- if (c->mtu)
- nl_link_set_mtu(nl_sock_ns, c->pasta_ifi, c->mtu);
-
- if (c->ifi6) /* Avoid duplicate address detection on link up */
- flags |= IFF_NOARP;
-
- nl_link_set_flags(nl_sock_ns, c->pasta_ifi, flags, flags);
-
- if (c->ifi4) {
- if (c->ip4.no_copy_addrs) {
- rc = nl_addr_set(nl_sock_ns, c->pasta_ifi,
- AF_INET,
- &c->ip4.addr,
- c->ip4.prefix_len);
- } else {
- rc = nl_addr_dup(nl_sock, c->ifi4,
- nl_sock_ns, c->pasta_ifi,
- AF_INET);
- }
-
- if (c->ifi4 == -1 && rc == -ENOTSUP) {
- warn("IPv4 not supported, disabling");
- c->ifi4 = 0;
- goto ipv4_done;
- }
-
- if (rc < 0) {
- die("Couldn't set IPv4 address(es) in namespace: %s",
- strerror_(-rc));
- }
-
- if (c->ip4.no_copy_routes) {
- rc = nl_route_set_def(nl_sock_ns, c->pasta_ifi,
- AF_INET,
- &c->ip4.guest_gw);
- } else {
- rc = nl_route_dup(nl_sock, c->ifi4, nl_sock_ns,
- c->pasta_ifi, AF_INET);
- }
-
- if (rc < 0) {
- die("Couldn't set IPv4 route(s) in guest: %s",
- strerror_(-rc));
- }
- }
-ipv4_done:
+ proto_update_l2_buf(c->guest_mac);
- if (c->ifi6) {
- rc = nl_addr_get_ll(nl_sock_ns, c->pasta_ifi,
- &c->ip6.addr_ll_seen);
- if (rc < 0) {
- warn("Can't get LL address from namespace: %s",
- strerror_(-rc));
- }
+ if (!c->pasta_conf_ns)
+ return;
- rc = nl_addr_set_ll_nodad(nl_sock_ns, c->pasta_ifi);
- if (rc < 0) {
- warn("Can't set nodad for LL in namespace: %s",
- strerror_(-rc));
- }
-
- /* We dodged DAD: re-enable neighbour solicitations */
- nl_link_set_flags(nl_sock_ns, c->pasta_ifi,
- 0, IFF_NOARP);
-
- if (c->ip6.no_copy_addrs) {
- if (!IN6_IS_ADDR_UNSPECIFIED(&c->ip6.addr)) {
- rc = nl_addr_set(nl_sock_ns,
- c->pasta_ifi, AF_INET6,
- &c->ip6.addr, 64);
- }
- } else {
- rc = nl_addr_dup(nl_sock, c->ifi6,
- nl_sock_ns, c->pasta_ifi,
- AF_INET6);
- }
-
- if (rc < 0) {
- die("Couldn't set IPv6 address(es) in namespace: %s",
- strerror_(-rc));
- }
-
- if (c->ip6.no_copy_routes) {
- rc = nl_route_set_def(nl_sock_ns, c->pasta_ifi,
- AF_INET6,
- &c->ip6.guest_gw);
- } else {
- rc = nl_route_dup(nl_sock, c->ifi6,
- nl_sock_ns, c->pasta_ifi,
- AF_INET6);
- }
-
- if (c->ifi6 == -1 && rc == -ENOTSUP) {
- warn("IPv6 not supported, disabling");
- c->ifi6 = 0;
- goto ipv6_done;
- }
-
- if (rc < 0) {
- die("Couldn't set IPv6 route(s) in guest: %s",
+ if (c->mtu)
+ nl_link_set_mtu(nl_sock_ns, c->pasta_ifi, c->mtu);
+
+ if (c->ifi6) /* Avoid duplicate address detection on link up */
+ flags |= IFF_NOARP;
+
+ nl_link_set_flags(nl_sock_ns, c->pasta_ifi, flags, flags);
+
+ if (c->ifi4) {
+ rc = pasta_conf_addrs(c, AF_INET, c->ifi4,
+ c->ip4.no_copy_addrs);
+ if (c->ifi4 == -1 && rc == -ENOTSUP) {
+ warn("IPv4 not supported, disabling");
+ c->ifi4 = 0;
+ } else if (rc < 0) {
+ die("Couldn't set IPv4 address(es) in namespace: %s",
+ strerror_(-rc));
+ } else {
+ rc = pasta_conf_routes(c, AF_INET, c->ifi4,
+ c->ip4.no_copy_routes);
+ if (rc < 0)
+ die("Couldn't set IPv4 route(s) in guest: %s",
strerror_(-rc));
- }
}
}
-ipv6_done:
- proto_update_l2_buf(c->guest_mac);
+ if (c->ifi6) {
+ rc = nl_addr_get_ll(nl_sock_ns, c->pasta_ifi,
+ &c->ip6.addr_ll_seen);
+ if (rc < 0)
+ warn("Can't get LL address from namespace: %s",
+ strerror_(-rc));
+
+ rc = nl_addr_set_ll_nodad(nl_sock_ns, c->pasta_ifi);
+ if (rc < 0)
+ warn("Can't set nodad for LL in namespace: %s",
+ strerror_(-rc));
+
+ /* We dodged DAD: re-enable neighbour solicitations */
+ nl_link_set_flags(nl_sock_ns, c->pasta_ifi, 0, IFF_NOARP);
+
+ rc = pasta_conf_addrs(c, AF_INET6, c->ifi6,
+ c->ip6.no_copy_addrs);
+ if (c->ifi6 == -1 && rc == -ENOTSUP) {
+ warn("IPv6 not supported, disabling");
+ c->ifi6 = 0;
+ return;
+ } else if (rc < 0) {
+ die("Couldn't set IPv6 address(es) in namespace: %s",
+ strerror_(-rc));
+ }
+
+ rc = pasta_conf_routes(c, AF_INET6, c->ifi6,
+ c->ip6.no_copy_routes);
+ if (rc < 0)
+ die("Couldn't set IPv6 route(s) in guest: %s",
+ strerror_(-rc));
+ }
}
/**
--
2.52.0