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 Reviewed-by: David Gibson --- 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 7ba5d75e..a9ee8348 100644 --- a/pasta.c +++ b/pasta.c @@ -290,13 +290,70 @@ void pasta_start_ns(struct ctx *c, int argc, char *argv[]) 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) @@ -315,116 +372,69 @@ 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