Configure additional addresses on the lo interface for network-sandbox
This works around some strange behavior in glibc's getaddrinfo()
implementation when the AI_ADDRCONFIG flag is set.
For example:
struct addrinfo *res, hints = { .ai_family = AF_INET, .ai_flags = AI_ADDRCONFIG };
getaddrinfo("localhost", NULL, &hints, &res);
This returns no results if there are no non-loopback addresses configured.
Bug: https://bugs.gentoo.org/690758
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=12377#c13
Reviewed-by: Zac Medico <zmedico@gentoo.org>
Signed-off-by: Mike Gilbert <floppym@gentoo.org>
diff --git a/lib/portage/process.py b/lib/portage/process.py
index dfbda75..77f7fac 100644
--- a/lib/portage/process.py
+++ b/lib/portage/process.py
@@ -446,6 +446,42 @@
# Everything succeeded
return 0
+def _configure_loopback_interface():
+ """
+ Configure the loopback interface.
+ """
+
+ IFF_UP = 0x1
+ ifreq = struct.pack('16sh', b'lo', IFF_UP)
+ SIOCSIFFLAGS = 0x8914
+
+ sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 0)
+ try:
+ fcntl.ioctl(sock, SIOCSIFFLAGS, ifreq)
+ except IOError as e:
+ writemsg("Unable to enable loopback interface: %s\n" % e.strerror, noiselevel=-1)
+ sock.close()
+
+ # We add some additional addresses to work around odd behavior in glibc's
+ # getaddrinfo() implementation when the AI_ADDRCONFIG flag is set.
+ #
+ # For example:
+ #
+ # struct addrinfo *res, hints = { .ai_family = AF_INET, .ai_flags = AI_ADDRCONFIG };
+ # getaddrinfo("localhost", NULL, &hints, &res);
+ #
+ # This returns no results if there are no non-loopback addresses
+ # configured for a given address family.
+ #
+ # Bug: https://bugs.gentoo.org/690758
+ # Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=12377#c13
+
+ try:
+ subprocess.call(['ip', 'address', 'add', '10.0.0.1/8', 'dev', 'lo'])
+ subprocess.call(['ip', 'address', 'add', 'fd00::1/8', 'dev', 'lo'])
+ except OSError as e:
+ writemsg("Error calling 'ip': %s\n" % e.strerror, noiselevel=-1)
+
def _exec(binary, mycommand, opt_name, fd_pipes,
env, gid, groups, uid, umask, cwd,
pre_exec, close_fds, unshare_net, unshare_ipc, unshare_mount, unshare_pid,
@@ -624,19 +660,7 @@
noiselevel=-1)
os._exit(1)
if unshare_net:
- # 'up' the loopback
- IFF_UP = 0x1
- ifreq = struct.pack('16sh', b'lo', IFF_UP)
- SIOCSIFFLAGS = 0x8914
-
- sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 0)
- try:
- fcntl.ioctl(sock, SIOCSIFFLAGS, ifreq)
- except IOError as e:
- writemsg("Unable to enable loopback interface: %s\n" % (
- errno.errorcode.get(e.errno, '?')),
- noiselevel=-1)
- sock.close()
+ _configure_loopback_interface()
except AttributeError:
# unshare() not supported by libc
pass
