> -----Original Message-----
> From: n...@orbyte.nwl.cc [mailto:n...@orbyte.nwl.cc] On Behalf Of Phil
> Sutter
> Sent: Wednesday, January 10, 2018 3:24 AM
> To: Chris Mi <chr...@mellanox.com>
> Cc: netdev@vger.kernel.org; gerlitz...@gmail.com;
> step...@networkplumber.org; dsah...@gmail.com;
> marcelo.leit...@gmail.com
> Subject: Re: [patch iproute2 v7 1/2] lib/libnetlink: Add functions
> rtnl_talk_msg and rtnl_talk_iov
>
> Hi,
>
> On Tue, Jan 09, 2018 at 03:59:07PM +0900, Chris Mi wrote:
> [...]
> > diff --git a/lib/libnetlink.c b/lib/libnetlink.c index
> > 00e6ce0c..ae0059f9 100644
> > --- a/lib/libnetlink.c
> > +++ b/lib/libnetlink.c
> > @@ -581,39 +581,43 @@ static void rtnl_talk_error(struct nlmsghdr *h,
> struct nlmsgerr *err,
> > strerror(-err->error));
> > }
> >
> > -static int __rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
> > - struct nlmsghdr **answer,
> > - bool show_rtnl_err, nl_ext_ack_fn_t errfn)
> > +static int __rtnl_talk_msg(struct rtnl_handle *rtnl, struct msghdr *m,
> > + struct nlmsghdr **answer,
> > + bool show_rtnl_err, nl_ext_ack_fn_t errfn)
> > {
> > - int status;
> > - unsigned int seq;
> > - struct nlmsghdr *h;
> > struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
> > - struct iovec iov = {
> > - .iov_base = n,
> > - .iov_len = n->nlmsg_len
> > - };
> > + int i, status, iovlen = m->msg_iovlen;
> > + struct iovec iov;
> > struct msghdr msg = {
> > .msg_name = &nladdr,
> > .msg_namelen = sizeof(nladdr),
> > .msg_iov = &iov,
> > .msg_iovlen = 1,
> > };
> > - char *buf;
> > -
> > - n->nlmsg_seq = seq = ++rtnl->seq;
> > + unsigned int seq = 0;
> > + struct nlmsghdr *h;
> >
> > - if (answer == NULL)
> > - n->nlmsg_flags |= NLM_F_ACK;
> > + for (i = 0; i < iovlen; i++) {
> > + struct iovec *v;
> > + v = &m->msg_iov[i];
> > + h = v->iov_base;
> > + h->nlmsg_seq = seq = ++rtnl->seq;
> > + if (answer == NULL)
> > + h->nlmsg_flags |= NLM_F_ACK;
> > + }
> >
> > - status = sendmsg(rtnl->fd, &msg, 0);
> > + status = sendmsg(rtnl->fd, m, 0);
> > if (status < 0) {
> > perror("Cannot talk to rtnetlink");
> > return -1;
> > }
> >
> > + i = 0;
> > while (1) {
>
> for (i = 1; ; i++) ?
>
> > + char *buf;
>
> Why did you move this declaration?
>
> > +next:
>
> Drop this and use 'continue' instead of 'goto next' below?
Actually there are two loops, I need go to the outer while loop instead of the
inner for loop.
>
> > status = rtnl_recvmsg(rtnl->fd, &msg, &buf);
> > + ++i;
> >
> > if (status < 0)
> > return status;
> > @@ -642,7 +646,7 @@ static int __rtnl_talk(struct rtnl_handle *rtnl,
> > struct nlmsghdr *n,
> >
> > if (nladdr.nl_pid != 0 ||
> > h->nlmsg_pid != rtnl->local.nl_pid ||
> > - h->nlmsg_seq != seq) {
> > + h->nlmsg_seq > seq || h->nlmsg_seq < seq - iovlen)
> {
> > /* Don't forget to skip that message. */
> > status -= NLMSG_ALIGN(len);
> > h = (struct nlmsghdr *)((char *)h +
> NLMSG_ALIGN(len)); @@ -662,7
> > +666,10 @@ static int __rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr
> *n,
> > *answer = (struct nlmsghdr
> *)buf;
> > else
> > free(buf);
> > - return 0;
> > + if (h->nlmsg_seq == seq)
> > + return 0;
> > + else
> > + goto next;
> > }
> >
> > if (rtnl->proto != NETLINK_SOCK_DIAG &&
>
> Cheers, Phil
