sockets: skip NULL ifa_addr entries in get_interfaces instead of stopping #56
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a-rank wants to merge 1 commit into
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sockets: skip NULL ifa_addr entries in get_interfaces instead of stopping #56a-rank wants to merge 1 commit into
a-rank wants to merge 1 commit into
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Pull request overview
This PR fixes a bug in the Unix implementation of rpp::ipinterface::get_interfaces where network interface enumeration would stop prematurely. The previous code used ifa->ifa_addr as part of the for loop continuation condition, meaning that as soon as getifaddrs returned an entry with ifa_addr == NULL (common for MAC-less TUN interfaces such as tailscale0 or wireguard), the loop terminated. This could result in an empty interface list. Since get_interfaces is a public API that also feeds get_ip_interface, get_system_ip, and get_broadcast_ip, this fix improves reliability of interface discovery on Linux/Unix systems that use such interfaces.
Changes:
- Moved the
ifa->ifa_addrNULL check out of the loop-continuation condition and into the loop body in both the counting and populating loops, so NULL entries are skipped instead of stopping enumeration. - Kept the counting loop and populating loop guards identical, ensuring the reserved capacity matches the number of emitted interfaces.
- Removed a trailing blank line at the end of the file.
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getifaddrs may return entries with ifa_addr==NULL, for example a MAC-less TUN like tailscale0 or wireguard. The loop used
ifa->ifa_addras its continuation condition, so enumeration stopped at the first such entry returning an empty list.