From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gandalf.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) by passt.top (Postfix) with ESMTPS id 653725A0282 for ; Mon, 24 Jul 2023 08:09:47 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=201602; t=1690178979; bh=xJnXPlG7PwFzMz0ADuiSWu3CQ4Pt5SGHnB+L8P635Jo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cITmqJxbvDbI/Bxa8APK8Qu2/uhSfHAuoHvH5+XLoTqli+Za2JJ1qtokYkweHdgil dPdTjKD1cKYsBv3FPAXn7Li9XKQWgBVohtw3szSB3NhOM4yWJiCnSJx+Vep+uiAbs4 XyiDoNQMUD0n5mCL0GLC2a+KKb+7SnI7rzEY7nYg= Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4R8V9v5wZXz4wyx; Mon, 24 Jul 2023 16:09:39 +1000 (AEST) From: David Gibson To: Stefano Brivio , passt-dev@passt.top Subject: [PATCH 16/17] netlink: Propagate errors for "dump" operations Date: Mon, 24 Jul 2023 16:09:35 +1000 Message-ID: <20230724060936.952659-17-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230724060936.952659-1-david@gibson.dropbear.id.au> References: <20230724060936.952659-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: QRAUF5GYRD2J7MYJNZQLCWAEBMYUMRB5 X-Message-ID-Hash: QRAUF5GYRD2J7MYJNZQLCWAEBMYUMRB5 X-MailFrom: dgibson@gandalf.ozlabs.org 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 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: Currently if we receive any netlink errors while discovering network configuration from the host, we'll just ignore it and carry on. This might lead to cryptic error messages later on, or even silent misconfiguration. We now have the mechanisms to detect errors from get/dump netlink operations. Propgate these errors up to the callers and report them usefully. Link: https://bugs.passt.top/show_bug.cgi?id=60 Signed-off-by: David Gibson --- conf.c | 65 +++++++++++++++++++++++++++++++++++++++++++------------ netlink.c | 19 ++++++++++++---- netlink.h | 8 +++---- 3 files changed, 70 insertions(+), 22 deletions(-) diff --git a/conf.c b/conf.c index 2e6e03f..14ec9f3 100644 --- a/conf.c +++ b/conf.c @@ -647,12 +647,24 @@ static unsigned int conf_ip4(unsigned int ifi, return 0; } - if (IN4_IS_ADDR_UNSPECIFIED(&ip4->gw)) - nl_route_get_def(nl_sock, ifi, AF_INET, &ip4->gw); + if (IN4_IS_ADDR_UNSPECIFIED(&ip4->gw)) { + int rc = nl_route_get_def(nl_sock, ifi, AF_INET, &ip4->gw); + if (rc < 0) { + err("Couldn't discover IPv4 gateway address: %s", + strerror(-rc)); + return 0; + } + } - if (IN4_IS_ADDR_UNSPECIFIED(&ip4->addr)) - nl_addr_get(nl_sock, ifi, AF_INET, - &ip4->addr, &ip4->prefix_len, NULL); + if (IN4_IS_ADDR_UNSPECIFIED(&ip4->addr)) { + int rc = nl_addr_get(nl_sock, ifi, AF_INET, + &ip4->addr, &ip4->prefix_len, NULL); + if (rc < 0) { + err("Couldn't discover IPv4 address: %s", + strerror(-rc)); + return 0; + } + } if (!ip4->prefix_len) { in_addr_t addr = ntohl(ip4->addr.s_addr); @@ -668,8 +680,15 @@ static unsigned int conf_ip4(unsigned int ifi, memcpy(&ip4->addr_seen, &ip4->addr, sizeof(ip4->addr_seen)); - if (MAC_IS_ZERO(mac)) - nl_link_get_mac(nl_sock, ifi, mac); + if (MAC_IS_ZERO(mac)) { + int rc = nl_link_get_mac(nl_sock, ifi, mac); + if (rc < 0) { + char ifname[IFNAMSIZ]; + err("Couldn't discover MAC for %s: %s", + if_indextoname(ifi, ifname), strerror(-rc)); + return 0; + } + } if (IN4_IS_ADDR_UNSPECIFIED(&ip4->addr) || MAC_IS_ZERO(mac)) @@ -690,6 +709,7 @@ static unsigned int conf_ip6(unsigned int ifi, struct ip6_ctx *ip6, unsigned char *mac) { int prefix_len = 0; + int rc; if (!ifi) ifi = nl_get_ext_if(nl_sock, AF_INET6); @@ -699,18 +719,35 @@ static unsigned int conf_ip6(unsigned int ifi, return 0; } - if (IN6_IS_ADDR_UNSPECIFIED(&ip6->gw)) - nl_route_get_def(nl_sock, ifi, AF_INET6, &ip6->gw); + if (IN6_IS_ADDR_UNSPECIFIED(&ip6->gw)) { + rc = nl_route_get_def(nl_sock, ifi, AF_INET6, &ip6->gw); + if (rc < 0) { + err("Couldn't discover IPv6 gateway address: %s", + strerror(-rc)); + return 0; + } + } - nl_addr_get(nl_sock, ifi, AF_INET6, - IN6_IS_ADDR_UNSPECIFIED(&ip6->addr) ? &ip6->addr : NULL, - &prefix_len, &ip6->addr_ll); + rc = nl_addr_get(nl_sock, ifi, AF_INET6, + IN6_IS_ADDR_UNSPECIFIED(&ip6->addr) ? &ip6->addr : NULL, + &prefix_len, &ip6->addr_ll); + if (rc < 0) { + err("Couldn't discover IPv6 address: %s", strerror(-rc)); + return 0; + } memcpy(&ip6->addr_seen, &ip6->addr, sizeof(ip6->addr)); memcpy(&ip6->addr_ll_seen, &ip6->addr_ll, sizeof(ip6->addr_ll)); - if (MAC_IS_ZERO(mac)) - nl_link_get_mac(0, ifi, mac); + if (MAC_IS_ZERO(mac)) { + rc = nl_link_get_mac(nl_sock, ifi, mac); + if (rc < 0) { + char ifname[IFNAMSIZ]; + err("Couldn't discover MAC for %s: %s", + if_indextoname(ifi, ifname), strerror(-rc)); + return 0; + } + } if (IN6_IS_ADDR_UNSPECIFIED(&ip6->addr) || IN6_IS_ADDR_UNSPECIFIED(&ip6->addr_ll) || diff --git a/netlink.c b/netlink.c index c57ee70..9e72b16 100644 --- a/netlink.c +++ b/netlink.c @@ -277,6 +277,8 @@ unsigned int nl_get_ext_if(int s, sa_family_t af) ifi = *(unsigned int *)RTA_DATA(rta); } } + if (status < 0) + warn("netlink: RTM_GETROUTE failed: %s", strerror(-status)); return ifi; } @@ -287,8 +289,10 @@ unsigned int nl_get_ext_if(int s, sa_family_t af) * @ifi: Interface index * @af: Address family * @gw: Default gateway to fill on NL_GET + * + * Return: 0 on success, negative error code on failure */ -void nl_route_get_def(int s, unsigned int ifi, sa_family_t af, void *gw) +int nl_route_get_def(int s, unsigned int ifi, sa_family_t af, void *gw) { struct req_t { struct nlmsghdr nlh; @@ -329,6 +333,7 @@ void nl_route_get_def(int s, unsigned int ifi, sa_family_t af, void *gw) found = true; } } + return status; } /** @@ -508,9 +513,11 @@ void nl_route_dup(int s_src, unsigned int ifi_src, * @addr: Global address to fill * @prefix_len: Mask or prefix length, to fill (for IPv4) * @addr_l: Link-scoped address to fill (for IPv6) + * + * Return: 9 on success, negative error code on failure */ -void nl_addr_get(int s, unsigned int ifi, sa_family_t af, - void *addr, int *prefix_len, void *addr_l) +int nl_addr_get(int s, unsigned int ifi, sa_family_t af, + void *addr, int *prefix_len, void *addr_l) { struct req_t { struct nlmsghdr nlh; @@ -551,6 +558,7 @@ void nl_addr_get(int s, unsigned int ifi, sa_family_t af, memcpy(addr_l, RTA_DATA(rta), RTA_PAYLOAD(rta)); } } + return status; } /** @@ -678,8 +686,10 @@ void nl_addr_dup(int s_src, unsigned int ifi_src, * @s: Netlink socket * @ifi: Interface index * @mac: Fill with current MAC address + * + * Return: 0 on success, negative error code on failure */ -void nl_link_get_mac(int s, unsigned int ifi, void *mac) +int nl_link_get_mac(int s, unsigned int ifi, void *mac) { struct req_t { struct nlmsghdr nlh; @@ -708,6 +718,7 @@ void nl_link_get_mac(int s, unsigned int ifi, void *mac) memcpy(mac, RTA_DATA(rta), ETH_ALEN); } } + return status; } /** diff --git a/netlink.h b/netlink.h index 977244b..b831405 100644 --- a/netlink.h +++ b/netlink.h @@ -11,17 +11,17 @@ extern int nl_sock_ns; void nl_sock_init(const struct ctx *c, bool ns); unsigned int nl_get_ext_if(int s, sa_family_t af); -void nl_route_get_def(int s, unsigned int ifi, sa_family_t af, void *gw); +int nl_route_get_def(int s, unsigned int ifi, sa_family_t af, void *gw); int nl_route_set_def(int s, unsigned int ifi, sa_family_t af, void *gw); void nl_route_dup(int s_src, unsigned int ifi_src, int s_dst, unsigned int ifi_dst, sa_family_t af); -void nl_addr_get(int s, unsigned int ifi, sa_family_t af, - void *addr, int *prefix_len, void *addr_l); +int nl_addr_get(int s, unsigned int ifi, sa_family_t af, + void *addr, int *prefix_len, void *addr_l); int nl_addr_set(int s, unsigned int ifi, sa_family_t af, void *addr, int prefix_len); void nl_addr_dup(int s_src, unsigned int ifi_src, int s_dst, unsigned int ifi_dst, sa_family_t af); -void nl_link_get_mac(int s, unsigned int ifi, void *mac); +int nl_link_get_mac(int s, unsigned int ifi, void *mac); int nl_link_set_mac(int s, unsigned int ifi, void *mac); int nl_link_up(int s, unsigned int ifi, int mtu); -- 2.41.0