| Message ID | 1499129577-34784-1-git-send-email-haifeng.lin@huawei.com |
|---|---|
| State | Accepted |
| Delegated to: | Ben Pfaff |
| Headers | show |
在 2017/7/12 12:55, Ben Pfaff 写道: > On Tue, Jul 04, 2017 at 08:52:57AM +0800, Haifeng Lin wrote: >> The ifa_netmask is null when failed to call ioctl >> in getifaddrs >> >> Signed-off-by: Haifeng Lin <haifeng.lin@huawei.com> > Thanks for figuring this out. > > What does it mean if ifa_netmask is null? Does it mean that the address > should be ignored entirely? The manpage for getifaddrs doesn't say. > And what about for IPv4 addresses? The glibc code shows that the ifa_netmask maybe NULL： ... if (__ioctl (fd, SIOCGIFNETMASK, ifr) < 0) storage[i].ia.ifa_netmask = NULL; else { storage[i].ia.ifa_netmask = &storage[i].netmask; storage[i].netmask = ifr->ifr_netmask; } ... > Maybe the right fix would be this: > > diff --git a/lib/netdev.c b/lib/netdev.c > index 26e87a2ee2ec..68003a829f27 100644 > --- a/lib/netdev.c > +++ b/lib/netdev.c > @@ -1967,7 +1967,8 @@ netdev_get_addrs(const char dev[], struct in6_addr **paddr, > for (ifa = if_addr_list; ifa; ifa = ifa->ifa_next) { > int family; > > - if (strncmp(ifa->ifa_name, dev, IFNAMSIZ) || ifa->ifa_addr == NULL) { > + if (strncmp(ifa->ifa_name, dev, IFNAMSIZ) > + || !ifa->ifa_addr || !ifa->ifa_netmask) { > continue; > } > > What do you think? I think we should check ifa_name too because we don't know what would happen in glibc and we should guarantee that ovs-vswitchd not crash. diff --git a/lib/netdev.c b/lib/netdev.c index a7840a8..12041f9 100644 --- a/lib/netdev.c +++ b/lib/netdev.c @@ -1942,7 +1942,7 @@ netdev_get_addrs(const char dev[], struct in6_addr **paddr, } for (ifa = if_addr_list; ifa; ifa = ifa->ifa_next) { - if (ifa->ifa_addr != NULL) { + if (ifa->ifa_addr && ifa->ifa_name) { int family; family = ifa->ifa_addr->sa_family; @@ -1963,7 +1963,8 @@ netdev_get_addrs(const char dev[], struct in6_addr **paddr, for (ifa = if_addr_list; ifa; ifa = ifa->ifa_next) { int family; - if (strncmp(ifa->ifa_name, dev, IFNAMSIZ) || ifa->ifa_addr == NULL) { + if (!ifa->ifa_name || !ifa->ifa_addr || !ifa->ifa_netmask + || strncmp(ifa->ifa_name, dev, IFNAMSIZ)) { continue; } > Thanks, > > Ben. > > . >
diff --git a/lib/netdev.c b/lib/netdev.c index a7840a8..c731b80 100644 --- a/lib/netdev.c +++ b/lib/netdev.c @@ -1982,7 +1982,8 @@ netdev_get_addrs(const char dev[], struct in6_addr **paddr, sin6 = ALIGNED_CAST(const struct sockaddr_in6 *, ifa->ifa_addr); memcpy(&addr_array[i], &sin6->sin6_addr, sizeof *addr_array); sin6 = ALIGNED_CAST(const struct sockaddr_in6 *, ifa->ifa_netmask); - memcpy(&mask_array[i], &sin6->sin6_addr, sizeof *mask_array); + if (sin6) + memcpy(&mask_array[i], &sin6->sin6_addr, sizeof *mask_array); i++; } }
The ifa_netmask is null when failed to call ioctl in getifaddrs Signed-off-by: Haifeng Lin <haifeng.lin@huawei.com> --- lib/netdev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)