flush secondary addresses before primary ones
Unless promote_secondaries has been active deleting the primary address of
an interface will automatically delete all the secondary addresses.
In the case where ip flush requests the primary then secondary addresses to
be removed - which is the order the addresses are returned by the kernel -
this will cause an error as by the time the request to remove a secondary
address is made it will be missing as it will have been deleted in the
course of deleting the primary address.
This approach to solving this problem orders requests for the
deletion of secondary addresses before primary ones providing
rtnl_dump_filter_l(), a version of rtnl_dump_filter() that
iterates over a list of filters. And by providing two specialised
filters print_addrinfo_secondary() and print_addrinfo_primary().
rtnl_dump_filter_l() first iterates over all addresses using
print_addrinfo_secondary(), which appends secondary addresses to the
request buffer. Then again using print_addrinfo_primary() which appends
primary addresses.
This approach should work regardless of it promote_secondaries is
active or not. And regardless of if any primary of secondary addresses
are present or not.
Signed-off-by: Simon Horman <horms@verge.net.au>
diff --git a/lib/libnetlink.c b/lib/libnetlink.c
index a6c0306..4ba6019 100644
--- a/lib/libnetlink.c
+++ b/lib/libnetlink.c
@@ -172,11 +172,8 @@
return sendmsg(rth->fd, &msg, 0);
}
-int rtnl_dump_filter(struct rtnl_handle *rth,
- rtnl_filter_t filter,
- void *arg1,
- rtnl_filter_t junk,
- void *arg2)
+int rtnl_dump_filter_l(struct rtnl_handle *rth,
+ const struct rtnl_dump_filter_arg *arg)
{
struct sockaddr_nl nladdr;
struct iovec iov;
@@ -191,7 +188,7 @@
iov.iov_base = buf;
while (1) {
int status;
- struct nlmsghdr *h;
+ const struct rtnl_dump_filter_arg *a;
iov.iov_len = sizeof(buf);
status = recvmsg(rth->fd, &msg, 0);
@@ -209,40 +206,45 @@
return -1;
}
- h = (struct nlmsghdr*)buf;
- while (NLMSG_OK(h, status)) {
- int err;
+ for (a = arg; a->filter; a++) {
+ struct nlmsghdr *h = (struct nlmsghdr*)buf;
- if (nladdr.nl_pid != 0 ||
- h->nlmsg_pid != rth->local.nl_pid ||
- h->nlmsg_seq != rth->dump) {
- if (junk) {
- err = junk(&nladdr, h, arg2);
- if (err < 0)
- return err;
- }
- goto skip_it;
- }
+ while (NLMSG_OK(h, status)) {
+ int err;
- if (h->nlmsg_type == NLMSG_DONE)
- return 0;
- if (h->nlmsg_type == NLMSG_ERROR) {
- struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
- if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
- fprintf(stderr, "ERROR truncated\n");
- } else {
- errno = -err->error;
- perror("RTNETLINK answers");
+ if (nladdr.nl_pid != 0 ||
+ h->nlmsg_pid != rth->local.nl_pid ||
+ h->nlmsg_seq != rth->dump) {
+ if (a->junk) {
+ err = a->junk(&nladdr, h,
+ a->arg2);
+ if (err < 0)
+ return err;
+ }
+ goto skip_it;
}
- return -1;
- }
- err = filter(&nladdr, h, arg1);
- if (err < 0)
- return err;
+
+ if (h->nlmsg_type == NLMSG_DONE)
+ return 0;
+ if (h->nlmsg_type == NLMSG_ERROR) {
+ struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
+ if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
+ fprintf(stderr,
+ "ERROR truncated\n");
+ } else {
+ errno = -err->error;
+ perror("RTNETLINK answers");
+ }
+ return -1;
+ }
+ err = a->filter(&nladdr, h, a->arg1);
+ if (err < 0)
+ return err;
skip_it:
- h = NLMSG_NEXT(h, status);
- }
+ h = NLMSG_NEXT(h, status);
+ }
+ } while (0);
if (msg.msg_flags & MSG_TRUNC) {
fprintf(stderr, "Message truncated\n");
continue;
@@ -254,6 +256,20 @@
}
}
+int rtnl_dump_filter(struct rtnl_handle *rth,
+ rtnl_filter_t filter,
+ void *arg1,
+ rtnl_filter_t junk,
+ void *arg2)
+{
+ const struct rtnl_dump_filter_arg a[2] = {
+ { .filter = filter, .arg1 = arg1, .junk = junk, .arg2 = arg2 },
+ { .filter = NULL, .arg1 = NULL, .junk = NULL, .arg2 = NULL }
+ };
+
+ return rtnl_dump_filter_l(rth, a);
+}
+
int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
unsigned groups, struct nlmsghdr *answer,
rtnl_filter_t junk,