From: Xiao Liang Date: Fri, 11 Oct 2024 08:01:09 +0000 (+0800) Subject: iplink: Fix link-netns id and link ifindex X-Git-Tag: v6.12.0~6 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a597ab156ba002bd84666c527db8b33ef661b56a;p=thirdparty%2Fiproute2.git iplink: Fix link-netns id and link ifindex When link-netns or link-netnsid is supplied, lookup link in that netns. And if both netns and link-netns are given, IFLA_LINK_NETNSID should be the nsid of link-netns from the view of target netns, not from current one. For example, when handling: # ip -n ns1 link add netns ns2 link-netns ns3 link eth1 eth1.100 type vlan id 100 should lookup eth1 in ns3 and IFLA_LINK_NETNSID is the id of ns3 from ns2. Signed-off-by: Xiao Liang Acked-by: Nicolas Dichtel Signed-off-by: Stephen Hemminger --- diff --git a/ip/iplink.c b/ip/iplink.c index c9168985..e650a5c2 100644 --- a/ip/iplink.c +++ b/ip/iplink.c @@ -240,6 +240,38 @@ static int nl_get_ll_addr_len(const char *ifname) return len; } +static int get_ifindex_in_netns(struct rtnl_handle *rtnl, int netnsid, + const char *ifname) +{ + struct { + struct nlmsghdr n; + struct ifinfomsg ifm; + char buf[1024]; + } req = { + .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)), + .n.nlmsg_flags = NLM_F_REQUEST, + .n.nlmsg_type = RTM_GETLINK, + }; + struct nlmsghdr *answer; + int ifindex; + + addattr32(&req.n, sizeof(req), IFLA_TARGET_NETNSID, netnsid); + addattr_l(&req.n, sizeof(req), + !check_ifname(ifname) ? IFLA_IFNAME : IFLA_ALT_IFNAME, + ifname, strlen(ifname) + 1); + + if (rtnl_talk(rtnl, &req.n, &answer) < 0) + return 0; + + if (answer->nlmsg_len < NLMSG_LENGTH(sizeof(struct ifinfomsg))) { + free(answer); + return 0; + } + ifindex = ((struct ifinfomsg *)NLMSG_DATA(answer))->ifi_index; + free(answer); + return ifindex; +} + static void iplink_parse_vf_vlan_info(int vf, int *argcp, char ***argvp, struct ifla_vf_vlan_info *ivvip) { @@ -536,7 +568,10 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req, char **type) int vf = -1; int numtxqueues = -1; int numrxqueues = -1; + char *link_netns = NULL; int link_netnsid = -1; + struct rtnl_handle netns_rtnl; + struct rtnl_handle *rtnl = &rth; int index = 0; int group = -1; int addr_len = 0; @@ -618,20 +653,25 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req, char **type) if (offload && name == dev) dev = NULL; } else if (strcmp(*argv, "netns") == 0) { + int pid; + NEXT_ARG(); if (netns != -1) duparg("netns", *argv); netns = netns_get_fd(*argv); - if (netns >= 0) { - open_fds_add(netns); - addattr_l(&req->n, sizeof(*req), IFLA_NET_NS_FD, - &netns, 4); + if (netns < 0 && get_integer(&pid, *argv, 0) == 0) { + char path[PATH_MAX]; + + snprintf(path, sizeof(path), "/proc/%d/ns/net", + pid); + netns = open(path, O_RDONLY); } - else if (get_integer(&netns, *argv, 0) == 0) - addattr_l(&req->n, sizeof(*req), - IFLA_NET_NS_PID, &netns, 4); - else + if (netns < 0) invarg("Invalid \"netns\" value\n", *argv); + + open_fds_add(netns); + addattr_l(&req->n, sizeof(*req), IFLA_NET_NS_FD, + &netns, 4); move_netns = true; } else if (strcmp(*argv, "multicast") == 0) { NEXT_ARG(); @@ -817,21 +857,12 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req, char **type) addattr_nest_end(&req->n, afs); } else if (matches(*argv, "link-netns") == 0) { NEXT_ARG(); - if (link_netnsid != -1) + if (link_netnsid != -1 || link_netns) duparg("link-netns/link-netnsid", *argv); - link_netnsid = netns_id_from_name(&rth, *argv); - /* No nsid? Try to assign one. */ - if (link_netnsid < 0) - set_netns_id_from_name(&rth, *argv, -1); - link_netnsid = netns_id_from_name(&rth, *argv); - if (link_netnsid < 0) - invarg("Invalid \"link-netns\" value\n", - *argv); - addattr32(&req->n, sizeof(*req), IFLA_LINK_NETNSID, - link_netnsid); + link_netns = *argv; } else if (matches(*argv, "link-netnsid") == 0) { NEXT_ARG(); - if (link_netnsid != -1) + if (link_netnsid != -1 || link_netns) duparg("link-netns/link-netnsid", *argv); if (get_integer(&link_netnsid, *argv, 0)) invarg("Invalid \"link-netnsid\" value\n", @@ -983,6 +1014,53 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req, char **type) } } + if (netns != -1 && (link_netnsid != -1 || link_netns)) { + int orig_netns; + + /* + * When both link-netns and netns are set, open an RTNL in + * target netns, to + * 1) get link-netns id from the view of target netns, and + * 2) get link ifindex from link-netns. + */ + orig_netns = open("/proc/self/ns/net", O_RDONLY); + if (orig_netns == -1) { + fprintf(stderr, "Cannot open namespace: %s\n", + strerror(errno)); + exit(-1); + } + if (setns(netns, CLONE_NEWNET) < 0) { + fprintf(stderr, "Cannot set namespace: %s\n", + strerror(errno)); + exit(-1); + } + if (rtnl_open(&netns_rtnl, 0) < 0) { + fprintf(stderr, "Cannot open rtnetlink\n"); + exit(-1); + } + if (setns(orig_netns, CLONE_NEWNET) < 0) { + fprintf(stderr, "Cannot set namespace: %s\n", + strerror(errno)); + exit(-1); + } + close(orig_netns); + rtnl = &netns_rtnl; + } + + if (link_netns) { + link_netnsid = netns_id_from_name(rtnl, link_netns); + /* No nsid? Try to assign one. */ + if (link_netnsid < 0) { + set_netns_id_from_name(rtnl, link_netns, -1); + link_netnsid = netns_id_from_name(rtnl, link_netns); + } + if (link_netnsid < 0) + invarg("Invalid \"link-netns\" value\n", + *argv); + addattr32(&req->n, sizeof(*req), IFLA_LINK_NETNSID, + link_netnsid); + } + if (!(req->n.nlmsg_flags & NLM_F_CREATE)) { if (!dev) { fprintf(stderr, @@ -991,8 +1069,10 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req, char **type) } req->i.ifi_index = ll_name_to_index(dev); - if (!req->i.ifi_index) - return nodev(dev); + if (!req->i.ifi_index) { + ret = nodev(dev); + goto out; + } /* Not renaming to the same name */ if (name == dev) @@ -1010,9 +1090,17 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req, char **type) if (link) { int ifindex; - ifindex = ll_name_to_index(link); - if (!ifindex) - return nodev(link); + if (link_netnsid == -1) + ifindex = ll_name_to_index(link); + else + ifindex = get_ifindex_in_netns(rtnl, + link_netnsid, + link); + + if (!ifindex) { + ret = nodev(link); + goto out; + } addattr32(&req->n, sizeof(*req), IFLA_LINK, ifindex); } @@ -1024,6 +1112,10 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req, char **type) IFLA_IFNAME, name, strlen(name) + 1); } +out: + if (rtnl == &netns_rtnl) + rtnl_close(rtnl); + return ret; }