On Fri, Jul 6, 2012 at 9:29 PM, Simon Paillard <simon.paillard@xxxxxxxxxxxxxxxxxxxxxx> wrote: > Hi, > > On Thu, Jul 05, 2012 at 11:33:06PM +0200, Adrian Dabrowski wrote: >> Version: manpages-dev 3.27-1ubuntu2 > > You should upgrade your manpages-dev version: > http://packages.ubuntu.com/search?keywords=manpages-dev > >> The example program source produces a Seg-Fault, when a device does >> not have an ifa->ifa_addr. (e.g. openvpn-tunnels, probably others >> (dialup?)) > > Thanks for reporting the issue, don't hesitate to report similar reports *that > still apply in current version*. > >> ORIGINAL: >> for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) { >> family = ifa->ifa_addr->sa_family; > > http://man7.org/linux/man-pages/man3/getifaddrs.3.html > > for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) { > if (ifa->ifa_addr == NULL) > continue; > > family = ifa->ifa_addr->sa_family; > > It has been fixed by > http://git.kernel.org/?p=docs/man-pages/man-pages.git;a=commitdiff;h=ebd05fecfe > >> POSSIBLE FIX: >> for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) { >> if (ifa->ifa_addr != NULL) >> family = ifa->ifa_addr->sa_family; >> else >> family = -1; >> Adrian, thanks for the note. Simon, thanks for the review. From the above, I think nothing needs to be applied, but: >> Also it is not documented, that struct sockaddr *ifa_addr might be NULL. I applied the following patch for 3.42: [[ --- a/man3/getifaddrs.3 +++ b/man3/getifaddrs.3 @@ -98,20 +98,22 @@ for a list of these flags). The .I ifa_addr field points to a structure containing the interface address. (The .I sa_family subfield should be consulted to determine the format of the address structure.) +This field may contain a NULL pointer. .PP The .I ifa_netmask field points to a structure containing the netmask associated with .IR ifa_addr , if applicable for the address family. +This field may contain a NULL pointer. .PP Depending on whether the bit .B IFF_BROADCAST or .B IFF_POINTOPOINT is set in .I ifa_flags ]] Thanks, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Author of "The Linux Programming Interface"; http://man7.org/tlpi/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
