From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by passt.top (Postfix, from userid 1000) id 22EEF5A0278; Thu, 15 Aug 2024 10:36:49 +0200 (CEST) From: Stefano Brivio To: passt-dev@passt.top Subject: [PATCH v2 2/7] netlink, pasta: Split MTU setting functionality out of nl_link_up() Date: Thu, 15 Aug 2024 10:36:44 +0200 Message-ID: <20240815083649.4188007-3-sbrivio@redhat.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240815083649.4188007-1-sbrivio@redhat.com> References: <20240815083649.4188007-1-sbrivio@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: V3Y2AFZIRFFBGJIRPLF3O2DD3FXJNLIS X-Message-ID-Hash: V3Y2AFZIRFFBGJIRPLF3O2DD3FXJNLIS X-MailFrom: sbrivio@passt.top X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: David Gibson , Paul Holzinger X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: As we'll use nl_link_up() for more than just bringing up devices, it will become awkward to carry empty MTU values around whenever we call it. Signed-off-by: Stefano Brivio Reviewed-by: David Gibson --- netlink.c | 35 +++++++++++++++++++++++++---------- netlink.h | 3 ++- pasta.c | 7 +++++-- 3 files changed, 32 insertions(+), 13 deletions(-) diff --git a/netlink.c b/netlink.c index e6a315e..e33765e 100644 --- a/netlink.c +++ b/netlink.c @@ -942,14 +942,14 @@ int nl_link_set_mac(int s, unsigned int ifi, const void *mac) } /** - * nl_link_up() - Bring link up + * nl_link_set_mtu() - Set link MTU * @s: Netlink socket * @ifi: Interface index - * @mtu: If non-zero, set interface MTU + * @mtu: Interface MTU * * Return: 0 on success, negative error code on failure */ -int nl_link_up(int s, unsigned int ifi, int mtu) +int nl_link_set_mtu(int s, unsigned int ifi, int mtu) { struct req_t { struct nlmsghdr nlh; @@ -959,17 +959,32 @@ int nl_link_up(int s, unsigned int ifi, int mtu) } req = { .ifm.ifi_family = AF_UNSPEC, .ifm.ifi_index = ifi, - .ifm.ifi_flags = IFF_UP, - .ifm.ifi_change = IFF_UP, .rta.rta_type = IFLA_MTU, .rta.rta_len = RTA_LENGTH(sizeof(unsigned int)), .mtu = mtu, }; - ssize_t len = sizeof(req); - if (!mtu) - /* Shorten request to drop MTU attribute */ - len = offsetof(struct req_t, rta); + return nl_do(s, &req, RTM_NEWLINK, 0, sizeof(req)); +} + +/** + * nl_link_up() - Bring link up + * @s: Netlink socket + * @ifi: Interface index + * + * Return: 0 on success, negative error code on failure + */ +int nl_link_up(int s, unsigned int ifi) +{ + struct req_t { + struct nlmsghdr nlh; + struct ifinfomsg ifm; + } req = { + .ifm.ifi_family = AF_UNSPEC, + .ifm.ifi_index = ifi, + .ifm.ifi_flags = IFF_UP, + .ifm.ifi_change = IFF_UP, + }; - return nl_do(s, &req, RTM_NEWLINK, 0, len); + return nl_do(s, &req, RTM_NEWLINK, 0, sizeof(req)); } diff --git a/netlink.h b/netlink.h index 3a1f0de..87d27ae 100644 --- a/netlink.h +++ b/netlink.h @@ -23,6 +23,7 @@ int nl_addr_dup(int s_src, unsigned int ifi_src, int s_dst, unsigned int ifi_dst, sa_family_t af); int nl_link_get_mac(int s, unsigned int ifi, void *mac); int nl_link_set_mac(int s, unsigned int ifi, const void *mac); -int nl_link_up(int s, unsigned int ifi, int mtu); +int nl_link_set_mtu(int s, unsigned int ifi, int mtu); +int nl_link_up(int s, unsigned int ifi); #endif /* NETLINK_H */ diff --git a/pasta.c b/pasta.c index 615ff7b..3a0652e 100644 --- a/pasta.c +++ b/pasta.c @@ -288,7 +288,7 @@ void pasta_ns_conf(struct ctx *c) { int rc = 0; - rc = nl_link_up(nl_sock_ns, 1 /* lo */, 0); + rc = nl_link_up(nl_sock_ns, 1 /* lo */); if (rc < 0) die("Couldn't bring up loopback interface in namespace: %s", strerror(-rc)); @@ -303,7 +303,10 @@ void pasta_ns_conf(struct ctx *c) strerror(-rc)); if (c->pasta_conf_ns) { - nl_link_up(nl_sock_ns, c->pasta_ifi, c->mtu); + if (c->mtu != -1) + nl_link_set_mtu(nl_sock_ns, c->pasta_ifi, c->mtu); + + nl_link_up(nl_sock_ns, c->pasta_ifi); if (c->ifi4) { if (c->ip4.no_copy_addrs) { -- 2.43.0