From: David Gibson <david@gibson.dropbear.id.au>
To: passt-dev@passt.top, Stefano Brivio <sbrivio@redhat.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH v2 16/17] netlink: Propagate errors for "dump" operations
Date: Thu, 3 Aug 2023 17:19:55 +1000 [thread overview]
Message-ID: <20230803071956.3198452-17-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20230803071956.3198452-1-david@gibson.dropbear.id.au>
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 <david@gibson.dropbear.id.au>
---
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 a60bd05..051d46c 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;
}
/**
@@ -507,9 +512,11 @@ 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;
@@ -550,6 +557,7 @@ void nl_addr_get(int s, unsigned int ifi, sa_family_t af,
memcpy(addr_l, RTA_DATA(rta), RTA_PAYLOAD(rta));
}
}
+ return status;
}
/**
@@ -677,8 +685,10 @@ 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;
@@ -707,6 +717,7 @@ 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);
--
@@ -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
next prev parent reply other threads:[~2023-08-03 7:20 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-03 7:19 [PATCH v2 00/17] netlink fixes and cleanups David Gibson
2023-08-03 7:19 ` [PATCH v2 01/17] netlink: Split up functionality of nl_link() David Gibson
2023-08-03 7:19 ` [PATCH v2 02/17] netlink: Split nl_addr() into separate operation functions David Gibson
2023-08-03 7:19 ` [PATCH v2 03/17] netlink: Split nl_route() " David Gibson
2023-08-03 7:19 ` [PATCH v2 04/17] netlink: Use struct in_addr for IPv4 addresses, not bare uint32_t David Gibson
2023-08-03 7:19 ` [PATCH v2 05/17] netlink: Explicitly pass netlink sockets to operations David Gibson
2023-08-03 7:19 ` [PATCH v2 06/17] netlink: Make nl_*_dup() use a separate datagram for each request David Gibson
2023-08-03 7:19 ` [PATCH v2 07/17] netlink: Start sequence number from 1 instead of 0 David Gibson
2023-08-03 7:19 ` [PATCH v2 08/17] netlink: Treat send() or recv() errors as fatal David Gibson
2023-08-03 7:19 ` [PATCH v2 09/17] netlink: Fill in netlink header fields from nl_req() David Gibson
2023-08-03 7:19 ` [PATCH v2 10/17] netlink: Add nl_do() helper for simple operations with error checking David Gibson
2023-08-03 7:19 ` [PATCH v2 11/17] netlink: Clearer reasoning about the netlink response buffer size David Gibson
2023-08-03 7:19 ` [PATCH v2 12/17] netlink: Split nl_req() to allow processing multiple response datagrams David Gibson
2023-08-03 7:19 ` [PATCH v2 13/17] netlink: Add nl_foreach_oftype to filter response message types David Gibson
2023-08-03 7:19 ` [PATCH v2 14/17] netlink: Propagate errors for "set" operations David Gibson
2023-08-03 7:19 ` [PATCH v2 15/17] netlink: Always process all responses to a netlink request David Gibson
2023-08-03 7:19 ` David Gibson [this message]
2023-08-03 7:19 ` [PATCH v2 17/17] netlink: Propagate errors for "dup" operations David Gibson
2023-08-04 7:04 ` [PATCH v2 00/17] netlink fixes and cleanups Stefano Brivio
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