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net.c
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net.c
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#include <unistd.h>
#include <sys/socket.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <string.h>
#include <net/if_arp.h>
#include <sys/wait.h>
#include <sched.h>
#include <sys/mount.h>
#include <net/if.h>
#include <linux/sockios.h>
#include "imgset.h"
#include "syscall-types.h"
#include "namespaces.h"
#include "net.h"
#include "libnetlink.h"
#include "cr_options.h"
#include "sk-inet.h"
#include "tun.h"
#include "util-pie.h"
#include "plugin.h"
#include "action-scripts.h"
#include "sockets.h"
#include "pstree.h"
#include "string.h"
#include "sysctl.h"
#include "kerndat.h"
#include "protobuf.h"
#include "protobuf/netdev.pb-c.h"
static int ns_sysfs_fd = -1;
int read_ns_sys_file(char *path, char *buf, int len)
{
int fd, rlen;
BUG_ON(ns_sysfs_fd == -1);
fd = openat(ns_sysfs_fd, path, O_RDONLY, 0);
if (fd < 0) {
pr_perror("Can't open ns' %s", path);
return -1;
}
rlen = read(fd, buf, len);
close(fd);
if (rlen == len) {
pr_err("Too small buffer to read ns sys file %s\n", path);
return -1;
}
if (rlen > 0)
buf[rlen - 1] = '\0';
return rlen;
}
static char *devconfs[] = {
"accept_local",
"accept_redirects",
"accept_source_route",
"arp_accept",
"arp_announce",
"arp_filter",
"arp_ignore",
"arp_notify",
"bootp_relay",
"disable_policy",
"disable_xfrm",
"force_igmp_version",
"forwarding",
"igmpv2_unsolicited_report_interval",
"igmpv3_unsolicited_report_interval",
"log_martians",
"medium_id",
"promote_secondaries",
"proxy_arp",
"proxy_arp_pvlan",
"route_localnet",
"rp_filter",
"secure_redirects",
"send_redirects",
"shared_media",
"src_valid_mark",
"tag",
"ignore_routes_with_linkdown",
};
/*
* I case if some entry is missing in
* the kernel, simply write DEVCONFS_UNUSED
* into the image so we would skip it.
*/
#define DEVCONFS_UNUSED (-1u)
#define NET_CONF_PATH "net/ipv4/conf"
#define MAX_CONF_OPT_PATH IFNAMSIZ+50
static int ipv4_conf_op(char *tgt, int *conf, int n, int op, NetnsEntry **netns)
{
int i, ri;
int ret, flags = op == CTL_READ ? CTL_FLAGS_OPTIONAL : 0;
struct sysctl_req req[ARRAY_SIZE(devconfs)];
char path[ARRAY_SIZE(devconfs)][MAX_CONF_OPT_PATH];
if (n > ARRAY_SIZE(devconfs))
pr_warn("The image contains unknown sysctl-s\n");
for (i = 0, ri = 0; i < ARRAY_SIZE(devconfs); i++) {
if (i >= n) {
pr_warn("Skip %s/%s\n", tgt, devconfs[i]);
continue;
}
/*
* If dev conf value is the same as default skip restoring it
*/
if (netns && conf[i] == (*netns)->def_conf[i]) {
pr_debug("DEBUG Skip %s/%s, val =%d\n", tgt, devconfs[i], conf[i]);
continue;
}
if (op == CTL_WRITE && conf[i] == DEVCONFS_UNUSED)
continue;
else if (op == CTL_READ)
conf[i] = DEVCONFS_UNUSED;
snprintf(path[i], MAX_CONF_OPT_PATH, "%s/%s/%s", NET_CONF_PATH, tgt, devconfs[i]);
req[ri].name = path[i];
req[ri].arg = &conf[i];
req[ri].type = CTL_32;
req[ri].flags = flags;
ri++;
}
ret = sysctl_op(req, ri, op, CLONE_NEWNET);
if (ret < 0) {
pr_err("Failed to %s %s/<confs>\n", (op == CTL_READ)?"read":"write", tgt);
return -1;
}
return 0;
}
int write_netdev_img(NetDeviceEntry *nde, struct cr_imgset *fds)
{
return pb_write_one(img_from_set(fds, CR_FD_NETDEV), nde, PB_NETDEV);
}
static int dump_one_netdev(int type, struct ifinfomsg *ifi,
struct rtattr **tb, struct cr_imgset *fds,
int (*dump)(NetDeviceEntry *, struct cr_imgset *))
{
int ret;
NetDeviceEntry netdev = NET_DEVICE_ENTRY__INIT;
if (!tb[IFLA_IFNAME]) {
pr_err("No name for link %d\n", ifi->ifi_index);
return -1;
}
netdev.type = type;
netdev.ifindex = ifi->ifi_index;
netdev.mtu = *(int *)RTA_DATA(tb[IFLA_MTU]);
netdev.flags = ifi->ifi_flags;
netdev.name = RTA_DATA(tb[IFLA_IFNAME]);
if (tb[IFLA_ADDRESS] && (type != ND_TYPE__LOOPBACK)) {
netdev.has_address = true;
netdev.address.data = RTA_DATA(tb[IFLA_ADDRESS]);
netdev.address.len = RTA_PAYLOAD(tb[IFLA_ADDRESS]);
pr_info("Found ll addr (%02x:../%d) for %s\n",
(int)netdev.address.data[0],
(int)netdev.address.len, netdev.name);
}
netdev.n_conf = ARRAY_SIZE(devconfs);
netdev.conf = xmalloc(sizeof(int) * netdev.n_conf);
if (!netdev.conf)
return -1;
ret = ipv4_conf_op(netdev.name, netdev.conf, netdev.n_conf, CTL_READ, NULL);
if (ret < 0)
goto err_free;
if (!dump)
dump = write_netdev_img;
ret = dump(&netdev, fds);
err_free:
xfree(netdev.conf);
return ret;
}
static char *link_kind(struct ifinfomsg *ifi, struct rtattr **tb)
{
struct rtattr *linkinfo[IFLA_INFO_MAX + 1];
if (!tb[IFLA_LINKINFO]) {
pr_err("No linkinfo for eth link %d\n", ifi->ifi_index);
return NULL;
}
parse_rtattr_nested(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO]);
if (!linkinfo[IFLA_INFO_KIND]) {
pr_err("No kind for eth link %d\n", ifi->ifi_index);
return NULL;
}
return RTA_DATA(linkinfo[IFLA_INFO_KIND]);
}
static int dump_unknown_device(struct ifinfomsg *ifi, char *kind,
struct rtattr **tb, struct cr_imgset *fds)
{
int ret;
ret = run_plugins(DUMP_EXT_LINK, ifi->ifi_index, ifi->ifi_type, kind);
if (ret == 0)
return dump_one_netdev(ND_TYPE__EXTLINK, ifi, tb, fds, NULL);
if (ret == -ENOTSUP)
pr_err("Unsupported link %d (type %d kind %s)\n",
ifi->ifi_index, ifi->ifi_type, kind);
return -1;
}
static int dump_bridge(NetDeviceEntry *nde, struct cr_imgset *imgset)
{
char spath[IFNAMSIZ + 16]; /* len("class/net//brif") + 1 for null */
int ret, fd;
ret = snprintf(spath, sizeof(spath), "class/net/%s/brif", nde->name);
if (ret < 0 || ret >= sizeof(spath))
return -1;
/* Let's only allow dumping empty bridges for now. To do a full bridge
* restore, we need to make sure the bridge and slaves are restored in
* the right order and attached correctly. It looks like the veth code
* supports this, but we need some way to do ordering.
*/
fd = openat(ns_sysfs_fd, spath, O_DIRECTORY, 0);
if (fd < 0) {
pr_perror("opening %s failed", spath);
return -1;
}
ret = is_empty_dir(fd);
close(fd);
if (ret < 0) {
pr_perror("problem testing %s for emptiness", spath);
return -1;
}
if (!ret) {
pr_err("dumping bridges with attached slaves not supported currently\n");
return -1;
}
return write_netdev_img(nde, imgset);
}
static int dump_one_ethernet(struct ifinfomsg *ifi, char *kind,
struct rtattr **tb, struct cr_imgset *fds)
{
if (!strcmp(kind, "veth"))
/*
* This is not correct. The peer of the veth device may
* be either outside or inside the netns we're working
* on, but there's currently no way of finding this out.
*
* Sigh... we have to assume, that the veth device is a
* connection to the outer world and just dump this end :(
*/
return dump_one_netdev(ND_TYPE__VETH, ifi, tb, fds, NULL);
if (!strcmp(kind, "tun"))
return dump_one_netdev(ND_TYPE__TUN, ifi, tb, fds, dump_tun_link);
if (!strcmp(kind, "bridge"))
return dump_one_netdev(ND_TYPE__BRIDGE, ifi, tb, fds, dump_bridge);
return dump_unknown_device(ifi, kind, tb, fds);
}
static int dump_one_gendev(struct ifinfomsg *ifi, char *kind,
struct rtattr **tb, struct cr_imgset *fds)
{
if (!strcmp(kind, "tun"))
return dump_one_netdev(ND_TYPE__TUN, ifi, tb, fds, dump_tun_link);
return dump_unknown_device(ifi, kind, tb, fds);
}
static int dump_one_voiddev(struct ifinfomsg *ifi, char *kind,
struct rtattr **tb, struct cr_imgset *fds)
{
if (!strcmp(kind, "venet"))
return dump_one_netdev(ND_TYPE__VENET, ifi, tb, fds, NULL);
return dump_unknown_device(ifi, kind, tb, fds);
}
static int dump_one_link(struct nlmsghdr *hdr, void *arg)
{
struct cr_imgset *fds = arg;
struct ifinfomsg *ifi;
int ret = 0, len = hdr->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));
struct rtattr *tb[IFLA_MAX + 1];
char *kind;
ifi = NLMSG_DATA(hdr);
if (len < 0) {
pr_err("No iflas for link %d\n", ifi->ifi_index);
return -1;
}
parse_rtattr(tb, IFLA_MAX, IFLA_RTA(ifi), len);
pr_info("\tLD: Got link %d, type %d\n", ifi->ifi_index, ifi->ifi_type);
if (ifi->ifi_type == ARPHRD_LOOPBACK)
return dump_one_netdev(ND_TYPE__LOOPBACK, ifi, tb, fds, NULL);
kind = link_kind(ifi, tb);
if (!kind)
goto unk;
switch (ifi->ifi_type) {
case ARPHRD_ETHER:
ret = dump_one_ethernet(ifi, kind, tb, fds);
break;
case ARPHRD_NONE:
ret = dump_one_gendev(ifi, kind, tb, fds);
break;
case ARPHRD_VOID:
ret = dump_one_voiddev(ifi, kind, tb, fds);
break;
default:
unk:
ret = dump_unknown_device(ifi, kind, tb, fds);
break;
}
return ret;
}
static int dump_links(struct cr_imgset *fds)
{
int sk, ret;
struct {
struct nlmsghdr nlh;
struct rtgenmsg g;
} req;
pr_info("Dumping netns links\n");
ret = sk = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
if (sk < 0) {
pr_perror("Can't open rtnl sock for net dump");
goto out;
}
memset(&req, 0, sizeof(req));
req.nlh.nlmsg_len = sizeof(req);
req.nlh.nlmsg_type = RTM_GETLINK;
req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
req.nlh.nlmsg_pid = 0;
req.nlh.nlmsg_seq = CR_NLMSG_SEQ;
req.g.rtgen_family = AF_PACKET;
ret = do_rtnl_req(sk, &req, sizeof(req), dump_one_link, NULL, fds);
close(sk);
out:
return ret;
}
static int restore_link_cb(struct nlmsghdr *hdr, void *arg)
{
pr_info("Got response on SETLINK =)\n");
return 0;
}
struct newlink_req {
struct nlmsghdr h;
struct ifinfomsg i;
char buf[1024];
};
static int do_rtm_link_req(int msg_type, NetDeviceEntry *nde, int nlsk,
int (*link_info)(NetDeviceEntry *, struct newlink_req *))
{
struct newlink_req req;
memset(&req, 0, sizeof(req));
req.h.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
req.h.nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK|NLM_F_CREATE;
req.h.nlmsg_type = msg_type;
req.h.nlmsg_seq = CR_NLMSG_SEQ;
req.i.ifi_family = AF_PACKET;
/*
* SETLINK is called for external devices which may
* have ifindex changed. Thus configure them by their
* name only.
*/
if (msg_type == RTM_NEWLINK)
req.i.ifi_index = nde->ifindex;
req.i.ifi_flags = nde->flags;
addattr_l(&req.h, sizeof(req), IFLA_IFNAME, nde->name, strlen(nde->name));
addattr_l(&req.h, sizeof(req), IFLA_MTU, &nde->mtu, sizeof(nde->mtu));
if (nde->has_address) {
pr_debug("Restore ll addr (%02x:../%d) for device\n",
(int)nde->address.data[0], (int)nde->address.len);
addattr_l(&req.h, sizeof(req), IFLA_ADDRESS,
nde->address.data, nde->address.len);
}
if (link_info) {
struct rtattr *linkinfo;
int ret;
linkinfo = NLMSG_TAIL(&req.h);
addattr_l(&req.h, sizeof(req), IFLA_LINKINFO, NULL, 0);
ret = link_info(nde, &req);
if (ret < 0)
return ret;
linkinfo->rta_len = (void *)NLMSG_TAIL(&req.h) - (void *)linkinfo;
}
return do_rtnl_req(nlsk, &req, req.h.nlmsg_len, restore_link_cb, NULL, NULL);
}
int restore_link_parms(NetDeviceEntry *nde, int nlsk)
{
return do_rtm_link_req(RTM_SETLINK, nde, nlsk, NULL);
}
static int restore_one_link(NetDeviceEntry *nde, int nlsk,
int (*link_info)(NetDeviceEntry *, struct newlink_req *))
{
pr_info("Restoring netdev %s idx %d\n", nde->name, nde->ifindex);
return do_rtm_link_req(RTM_NEWLINK, nde, nlsk, link_info);
}
#ifndef VETH_INFO_MAX
enum {
VETH_INFO_UNSPEC,
VETH_INFO_PEER,
__VETH_INFO_MAX
#define VETH_INFO_MAX (__VETH_INFO_MAX - 1)
};
#endif
#if IFLA_MAX <= 28
#define IFLA_NET_NS_FD 28
#endif
static int veth_link_info(NetDeviceEntry *nde, struct newlink_req *req)
{
int ns_fd = get_service_fd(NS_FD_OFF);
struct rtattr *veth_data, *peer_data;
struct ifinfomsg ifm;
struct veth_pair *n;
BUG_ON(ns_fd < 0);
addattr_l(&req->h, sizeof(*req), IFLA_INFO_KIND, "veth", 4);
veth_data = NLMSG_TAIL(&req->h);
addattr_l(&req->h, sizeof(*req), IFLA_INFO_DATA, NULL, 0);
peer_data = NLMSG_TAIL(&req->h);
memset(&ifm, 0, sizeof(ifm));
addattr_l(&req->h, sizeof(*req), VETH_INFO_PEER, &ifm, sizeof(ifm));
list_for_each_entry(n, &opts.veth_pairs, node) {
if (!strcmp(nde->name, n->inside))
break;
}
if (&n->node != &opts.veth_pairs)
addattr_l(&req->h, sizeof(*req), IFLA_IFNAME, n->outside, strlen(n->outside));
addattr_l(&req->h, sizeof(*req), IFLA_NET_NS_FD, &ns_fd, sizeof(ns_fd));
peer_data->rta_len = (void *)NLMSG_TAIL(&req->h) - (void *)peer_data;
veth_data->rta_len = (void *)NLMSG_TAIL(&req->h) - (void *)veth_data;
return 0;
}
static int venet_link_info(NetDeviceEntry *nde, struct newlink_req *req)
{
int ns_fd = get_service_fd(NS_FD_OFF);
struct rtattr *venet_data;
BUG_ON(ns_fd < 0);
venet_data = NLMSG_TAIL(&req->h);
addattr_l(&req->h, sizeof(*req), IFLA_INFO_KIND, "venet", 5);
addattr_l(&req->h, sizeof(*req), IFLA_INFO_DATA, NULL, 0);
addattr_l(&req->h, sizeof(*req), IFLA_NET_NS_FD, &ns_fd, sizeof(ns_fd));
venet_data->rta_len = (void *)NLMSG_TAIL(&req->h) - (void *)venet_data;
return 0;
}
static int bridge_link_info(NetDeviceEntry *nde, struct newlink_req *req)
{
struct rtattr *bridge_data;
bridge_data = NLMSG_TAIL(&req->h);
addattr_l(&req->h, sizeof(*req), IFLA_INFO_KIND, "bridge", sizeof("bridge"));
bridge_data->rta_len = (void *)NLMSG_TAIL(&req->h) - (void *)bridge_data;
return 0;
}
static int restore_link(NetDeviceEntry *nde, int nlsk)
{
pr_info("Restoring link %s type %d\n", nde->name, nde->type);
switch (nde->type) {
case ND_TYPE__LOOPBACK: /* fallthrough */
case ND_TYPE__EXTLINK: /* see comment in protobuf/netdev.proto */
return restore_link_parms(nde, nlsk);
case ND_TYPE__VENET:
return restore_one_link(nde, nlsk, venet_link_info);
case ND_TYPE__VETH:
return restore_one_link(nde, nlsk, veth_link_info);
case ND_TYPE__TUN:
return restore_one_tun(nde, nlsk);
case ND_TYPE__BRIDGE:
return restore_one_link(nde, nlsk, bridge_link_info);
default:
pr_err("Unsupported link type %d\n", nde->type);
break;
}
return -1;
}
static int restore_links(int pid, NetnsEntry **netns)
{
int nlsk, ret;
struct cr_img *img;
NetDeviceEntry *nde;
img = open_image(CR_FD_NETDEV, O_RSTR, pid);
if (!img)
return -1;
nlsk = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
if (nlsk < 0) {
pr_perror("Can't create nlk socket");
close_image(img);
return -1;
}
while (1) {
ret = pb_read_one_eof(img, &nde, PB_NETDEV);
if (ret <= 0)
break;
ret = restore_link(nde, nlsk);
if (ret) {
pr_err("Can't restore link\n");
goto exit;
}
if (nde->conf) {
NetnsEntry **def_netns = netns;
/*
* optimize restore of devices configuration except lo
* lo is created with namespace and before default is set
* so we cant optimize its restore
*/
if (nde->type == ND_TYPE__LOOPBACK)
def_netns = NULL;
ret = ipv4_conf_op(nde->name, nde->conf, nde->n_conf, CTL_WRITE, def_netns);
}
exit:
net_device_entry__free_unpacked(nde, NULL);
if (ret)
break;
}
close(nlsk);
close_image(img);
return ret;
}
static int run_ip_tool(char *arg1, char *arg2, char *arg3, int fdin, int fdout, unsigned flags)
{
char *ip_tool_cmd;
int ret;
pr_debug("\tRunning ip %s %s\n", arg1, arg2);
ip_tool_cmd = getenv("CR_IP_TOOL");
if (!ip_tool_cmd)
ip_tool_cmd = "ip";
ret = cr_system(fdin, fdout, -1, ip_tool_cmd,
(char *[]) { "ip", arg1, arg2, arg3, NULL }, flags);
if (ret) {
if (!(flags & CRS_CAN_FAIL))
pr_err("IP tool failed on %s %s\n", arg1, arg2);
return -1;
}
return 0;
}
static int run_iptables_tool(char *def_cmd, int fdin, int fdout)
{
int ret;
char *cmd;
cmd = getenv("CR_IPTABLES");
if (!cmd)
cmd = def_cmd;
pr_debug("\tRunning %s for %s\n", cmd, def_cmd);
ret = cr_system(fdin, fdout, -1, "sh", (char *[]) { "sh", "-c", cmd, NULL }, 0);
if (ret)
pr_err("%s failed\n", def_cmd);
return ret;
}
static inline int dump_ifaddr(struct cr_imgset *fds)
{
struct cr_img *img = img_from_set(fds, CR_FD_IFADDR);
return run_ip_tool("addr", "save", NULL, -1, img_raw_fd(img), 0);
}
static inline int dump_route(struct cr_imgset *fds)
{
struct cr_img *img;
img = img_from_set(fds, CR_FD_ROUTE);
if (run_ip_tool("route", "save", NULL, -1, img_raw_fd(img), 0))
return -1;
/* If ipv6 is disabled, "ip -6 route dump" dumps all routes */
if (!kdat.ipv6)
return 0;
img = img_from_set(fds, CR_FD_ROUTE6);
if (run_ip_tool("-6", "route", "save", -1, img_raw_fd(img), 0))
return -1;
return 0;
}
static inline int dump_rule(struct cr_imgset *fds)
{
struct cr_img *img;
char *path;
img = img_from_set(fds, CR_FD_RULE);
path = xstrdup(img->path);
if (!path)
return -1;
if (run_ip_tool("rule", "save", NULL, -1, img_raw_fd(img), CRS_CAN_FAIL)) {
pr_warn("Check if \"ip rule save\" is supported!\n");
unlinkat(get_service_fd(IMG_FD_OFF), path, 0);
}
free(path);
return 0;
}
static inline int dump_iptables(struct cr_imgset *fds)
{
struct cr_img *img;
img = img_from_set(fds, CR_FD_IPTABLES);
if (run_iptables_tool("iptables-save", -1, img_raw_fd(img)))
return -1;
if (kdat.ipv6) {
img = img_from_set(fds, CR_FD_IP6TABLES);
if (run_iptables_tool("ip6tables-save", -1, img_raw_fd(img)))
return -1;
}
return 0;
}
static int dump_netns_conf(struct cr_imgset *fds)
{
int ret, n;
NetnsEntry netns = NETNS_ENTRY__INIT;
netns.n_def_conf = ARRAY_SIZE(devconfs);
netns.n_all_conf = ARRAY_SIZE(devconfs);
netns.def_conf = xmalloc(sizeof(int) * netns.n_def_conf);
if (!netns.def_conf)
return -1;
netns.all_conf = xmalloc(sizeof(int) * netns.n_all_conf);
if (!netns.all_conf) {
xfree(netns.def_conf);
return -1;
}
n = netns.n_def_conf;
ret = ipv4_conf_op("default", netns.def_conf, n, CTL_READ, NULL);
if (ret < 0)
goto err_free;
ret = ipv4_conf_op("all", netns.all_conf, n, CTL_READ, NULL);
if (ret < 0)
goto err_free;
ret = pb_write_one(img_from_set(fds, CR_FD_NETNS), &netns, PB_NETNS);
err_free:
xfree(netns.def_conf);
xfree(netns.all_conf);
return ret;
}
static int restore_ip_dump(int type, int pid, char *cmd)
{
int ret = -1;
struct cr_img *img;
img = open_image(type, O_RSTR, pid);
if (empty_image(img)) {
close_image(img);
return 0;
}
if (img) {
ret = run_ip_tool(cmd, "restore", NULL, img_raw_fd(img), -1, 0);
close_image(img);
}
return ret;
}
static inline int restore_ifaddr(int pid)
{
return restore_ip_dump(CR_FD_IFADDR, pid, "addr");
}
static inline int restore_route(int pid)
{
if (restore_ip_dump(CR_FD_ROUTE, pid, "route"))
return -1;
if (restore_ip_dump(CR_FD_ROUTE6, pid, "route"))
return -1;
return 0;
}
static inline int restore_rule(int pid)
{
struct cr_img *img;
int ret = 0;
img = open_image(CR_FD_RULE, O_RSTR, pid);
if (!img) {
ret = -1;
goto out;
}
if (empty_image(img))
goto close;
/*
* Delete 3 default rules to prevent duplicates. See kernel's
* function fib_default_rules_init() for the details.
*/
run_ip_tool("rule", "delete", NULL, -1, -1, 0);
run_ip_tool("rule", "delete", NULL, -1, -1, 0);
run_ip_tool("rule", "delete", NULL, -1, -1, 0);
if (restore_ip_dump(CR_FD_RULE, pid, "rule"))
ret = -1;
close:
close_image(img);
out:
return ret;
}
static inline int restore_iptables(int pid)
{
int ret = -1;
struct cr_img *img;
img = open_image(CR_FD_IPTABLES, O_RSTR, pid);
if (img) {
ret = run_iptables_tool("iptables-restore", img_raw_fd(img), -1);
close_image(img);
}
if (ret)
return ret;
img = open_image(CR_FD_IP6TABLES, O_RSTR, pid);
if (img == NULL)
return -1;
if (empty_image(img))
goto out;
ret = run_iptables_tool("ip6tables-restore", img_raw_fd(img), -1);
out:
close_image(img);
return ret;
}
static int restore_netns_conf(int pid, NetnsEntry **netns)
{
int ret = 0, n;
struct cr_img *img;
img = open_image(CR_FD_NETNS, O_RSTR, pid);
if (!img)
return -1;
if (empty_image(img))
/* Backward compatibility */
goto out;
ret = pb_read_one(img, netns, PB_NETNS);
if (ret < 0) {
pr_err("Can not read netns object\n");
return -1;
}
n = (*netns)->n_def_conf;
ret = ipv4_conf_op("default", (*netns)->def_conf, n, CTL_WRITE, NULL);
if (ret)
goto out;
ret = ipv4_conf_op("all", (*netns)->all_conf, n, CTL_WRITE, NULL);
out:
close_image(img);
return ret;
}
static int mount_ns_sysfs(void)
{
char sys_mount[] = "crtools-sys.XXXXXX";
BUG_ON(ns_sysfs_fd != -1);
/*
* A new mntns is required to avoid the race between
* open_detach_mount and creating mntns.
*/
if (unshare(CLONE_NEWNS)) {
pr_perror("Can't create new mount namespace");
return -1;
}
if (mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL)) {
pr_perror("Can't mark the root mount as private");
return -1;
}
if (mkdtemp(sys_mount) == NULL) {
pr_perror("mkdtemp failed %s", sys_mount);
return -1;
}
/*
* The setns() is called, so we're in proper context,
* no need in pulling the mountpoint from parasite.
*/
pr_info("Mount ns' sysfs in %s\n", sys_mount);
if (mount("sysfs", sys_mount, "sysfs", MS_MGC_VAL, NULL)) {
pr_perror("mount failed");
rmdir(sys_mount);
return -1;
}
ns_sysfs_fd = open_detach_mount(sys_mount);
return ns_sysfs_fd >= 0 ? 0 : -1;
}
int dump_net_ns(int ns_id)
{
struct cr_imgset *fds;
int ret;
fds = cr_imgset_open(ns_id, NETNS, O_DUMP);
if (fds == NULL)
return -1;
ret = mount_ns_sysfs();
if (!ret)
ret = dump_netns_conf(fds);
if (!ret)
ret = dump_links(fds);
if (!ret)
ret = dump_ifaddr(fds);
if (!ret)
ret = dump_route(fds);
if (!ret)
ret = dump_rule(fds);
if (!ret)
ret = dump_iptables(fds);
close(ns_sysfs_fd);
ns_sysfs_fd = -1;
close_cr_imgset(&fds);
return ret;
}
int prepare_net_ns(int pid)
{
int ret;
NetnsEntry *netns = NULL;
ret = restore_netns_conf(pid, &netns);
if (!ret)
ret = restore_links(pid, &netns);
if (netns)
netns_entry__free_unpacked(netns, NULL);
if (!ret)
ret = restore_ifaddr(pid);
if (!ret)
ret = restore_route(pid);
if (!ret)
ret = restore_rule(pid);
if (!ret)
ret = restore_iptables(pid);
close_service_fd(NS_FD_OFF);
return ret;
}
int netns_keep_nsfd(void)
{
int ns_fd, ret;
if (!(root_ns_mask & CLONE_NEWNET))
return 0;
/*
* When restoring a net namespace we need to communicate
* with the original (i.e. -- init) one. Thus, prepare for
* that before we leave the existing namespaces.
*/
ns_fd = open("/proc/self/ns/net", O_RDONLY | O_CLOEXEC);
if (ns_fd < 0) {
pr_perror("Can't cache net fd");
return -1;
}
ret = install_service_fd(NS_FD_OFF, ns_fd);
if (ret < 0)
pr_err("Can't install ns net reference\n");
else
pr_info("Saved netns fd for links restore\n");
close(ns_fd);
return ret >= 0 ? 0 : -1;
}
/*
* If we want to modify iptables, we need to recevied the current
* configuration, change it and load a new one into the kernel.
* iptables can change or add only one rule.
* iptables-restore allows to make a few changes for one iteration,
* so it works faster.
*/
static int iptables_restore(bool ipv6, char *buf, int size)
{
int pfd[2], ret = -1;
char *cmd4[] = {"iptables-restore", "--noflush", NULL};
char *cmd6[] = {"ip6tables-restore", "--noflush", NULL};
char **cmd = ipv6 ? cmd6 : cmd4;;
if (pipe(pfd) < 0) {
pr_perror("Unable to create pipe");
return -1;
}
if (write(pfd[1], buf, size) < size) {
pr_perror("Unable to write iptables configugration");
goto err;
}
close_safe(&pfd[1]);
ret = cr_system(pfd[0], -1, -1, cmd[0], cmd, 0);
err:
close_safe(&pfd[1]);
close_safe(&pfd[0]);
return ret;
}