On Fri, Sep 28, 2018 at 08:45:02AM -0700, dsah...@kernel.org wrote: > From: David Ahern <dsah...@gmail.com> > > Update inet6_dump_addr to check for NLM_F_DUMP_PROPER_HDR in the netlink > message header. If the flag is set, the dump request is expected to have > an ifaddrmsg struct as the header potentially followed by one or more > attributes. Any data passed in the header or as an attribute is taken as > a request to influence the data returned. Only values suppored by the > dump handler are allowed to be non-0 or set in the request. At the moment > only the IFA_TARGET_NETNSID attribute is supported. Follow on patches > will support for other fields (e.g., honor ifa_index and only return data > for the given device index). > > Signed-off-by: David Ahern <dsah...@gmail.com> > --- > net/ipv6/addrconf.c | 50 ++++++++++++++++++++++++++++++++++++++++---------- > 1 file changed, 40 insertions(+), 10 deletions(-) > > diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c > index 375ea9d9869b..888e5a4b8dd2 100644 > --- a/net/ipv6/addrconf.c > +++ b/net/ipv6/addrconf.c > @@ -5001,6 +5001,8 @@ static int in6_dump_addrs(struct inet6_dev *idev, > struct sk_buff *skb, > static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, > enum addr_type_t type) > { > + struct netlink_ext_ack *extack = cb->extack; > + const struct nlmsghdr *nlh = cb->nlh; > struct inet6_fill_args fillargs = { > .portid = NETLINK_CB(cb->skb).portid, > .seq = cb->nlh->nlmsg_seq, > @@ -5009,7 +5011,6 @@ static int inet6_dump_addr(struct sk_buff *skb, struct > netlink_callback *cb, > .type = type, > }; > struct net *net = sock_net(skb->sk); > - struct nlattr *tb[IFA_MAX+1]; > struct net *tgt_net = net; > int h, s_h; > int idx, ip_idx; > @@ -5022,17 +5023,46 @@ static int inet6_dump_addr(struct sk_buff *skb, > struct netlink_callback *cb, > s_idx = idx = cb->args[1]; > s_ip_idx = ip_idx = cb->args[2]; > > - if (nlmsg_parse(cb->nlh, sizeof(struct ifaddrmsg), tb, IFA_MAX, > - ifa_ipv6_policy, NULL) >= 0) { > - if (tb[IFA_TARGET_NETNSID]) { > - fillargs.netnsid = nla_get_s32(tb[IFA_TARGET_NETNSID]); > + if (nlh->nlmsg_flags & NLM_F_DUMP_PROPER_HDR) { > + struct nlattr *tb[IFA_MAX+1]; > + struct ifaddrmsg *ifm; > + int err, i; > + > + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) { > + NL_SET_ERR_MSG(extack, "Invalid header"); > + return -EINVAL; > + } > > - tgt_net = rtnl_get_net_ns_capable(skb->sk, > - fillargs.netnsid); > - if (IS_ERR(tgt_net)) > - return PTR_ERR(tgt_net); > + ifm = (struct ifaddrmsg *)nlmsg_data(cb->nlh); > + if (ifm->ifa_prefixlen || ifm->ifa_flags || ifm->ifa_scope) { > + NL_SET_ERR_MSG(extack, "Invalid values in header for > dump request"); > + return -EINVAL; > + } > + if (ifm->ifa_index) { > + NL_SET_ERR_MSG(extack, "Filter by device index not > supported"); > + return -EINVAL; > + } > > - fillargs.flags |= NLM_F_DUMP_FILTERED; > + err = nlmsg_parse(cb->nlh, sizeof(struct ifaddrmsg), tb, > IFA_MAX, > + ifa_ipv6_policy, NULL); > + if (err < 0) > + return err; > + > + for (i = 0; i < IFA_MAX; ++i) { > + if (i == IFA_TARGET_NETNSID) { > + fillargs.netnsid = nla_get_s32(tb[i]); > + > + tgt_net = rtnl_get_net_ns_capable(skb->sk, > + > fillargs.netnsid); > + if (IS_ERR(tgt_net)) > + return PTR_ERR(tgt_net); > + > + fillargs.flags |= NLM_F_DUMP_FILTERED; > + } > + if (tb[i]) { > + NL_SET_ERR_MSG(extack, "Unsupported attribute > in dump request"); > + return -EINVAL; > + }
Same comment/question as for ipv4. Shouldn't it be: for (i = 0; i < IFA_MAX; ++i) { if (i == IFA_TARGET_NETNSID && tb[i]) { fillargs.netnsid = nla_get_s32(tb[i]); tgt_net = rtnl_get_net_ns_capable(skb->sk, fillargs.netnsid); if (IS_ERR(tgt_net)) return PTR_ERR(tgt_net); fillargs.flags |= NLM_F_DUMP_FILTERED; continue; } if (tb[i]) { NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); return -EINVAL; } > } > } > > -- > 2.11.0 >