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Commit fed29fad by Tycho Andersen Committed by Serge Hallyn
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c/r: refactor the way we pass data to criu/scripts

We previously wrote a bunch of files (eth*, veth*, and bridge*) as hard coded files which we used as the names of interfaces to restore via criu's --veth-pair. This meant that if people, e.g. gave a different bridge on their new host, we would use our saved bridge in bridge* and try to restore to the wrong bridge. Instead, we can just generate a new veth id (if the user hasn't provided one), and use whatever the user configured values for the interface name and bridge are. This allows people to switch the bridge that they restore onto simply by migrating the rootfs and config, and then changing the bridge name in the container's configuration before running lxc-checkpoint. Signed-off-by: 's avatarTycho Andersen <tycho.andersen@canonical.com> Signed-off-by: 's avatarSerge Hallyn <serge.hallyn@ubuntu.com>
parent bbd4e13e
Showing with 68 additions and 74 deletions
src/lxc/lxc-restore-net
#!/bin/sh #!/bin/sh
[ -z "$CRTOOLS_IMAGE_DIR" ] && exit 1
set -e set -e
dir="$CRTOOLS_IMAGE_DIR"
i=0 i=0
while [ -f "$dir/eth$i" ] && [ -f "$dir/veth$i" ] && [ -f "$dir/bridge$i" ]; do while true; do
veth=$(cat "$dir/veth$i") eval "bridge=\$LXC_CRIU_BRIDGE$i"
bridge=$(cat "$dir/bridge$i") eval "veth=\$LXC_CRIU_VETH$i"
if [ -z "$bridge" ] || [ -z "$veth" ]; then
exit 0
fi
if [ "$CRTOOLS_SCRIPT_ACTION" = "network-lock" ]; then if [ "$CRTOOLS_SCRIPT_ACTION" = "network-lock" ]; then
brctl delif $bridge $veth brctl delif $bridge $veth
...@@ -22,3 +22,5 @@ while [ -f "$dir/eth$i" ] && [ -f "$dir/veth$i" ] && [ -f "$dir/bridge$i" ]; do ...@@ -22,3 +22,5 @@ while [ -f "$dir/eth$i" ] && [ -f "$dir/veth$i" ] && [ -f "$dir/bridge$i" ]; do
i=$((i+1)) i=$((i+1))
done done
exit 1
src/lxc/lxccontainer.c
...@@ -55,6 +55,7 @@ ...@@ -55,6 +55,7 @@
#include "attach.h" #include "attach.h"
#include "monitor.h" #include "monitor.h"
#include "namespace.h" #include "namespace.h"
#include "network.h"
#include "lxclock.h" #include "lxclock.h"
#include "sync.h" #include "sync.h"
...@@ -3536,37 +3537,12 @@ struct criu_opts { ...@@ -3536,37 +3537,12 @@ struct criu_opts {
const char *cgroup_path; const char *cgroup_path;
}; };
/*
* @out must be 128 bytes long
*/
static int read_criu_file(const char *directory, const char *file, int netnr, char *out)
{
char path[PATH_MAX];
int ret;
FILE *f;
ret = snprintf(path, PATH_MAX, "%s/%s%d", directory, file, netnr);
if (ret < 0 || ret >= PATH_MAX) {
ERROR("%s: path too long", __func__);
return -1;
}
f = fopen(path, "r");
if (!f)
return -1;
ret = fscanf(f, "%127s", out);
fclose(f);
if (ret <= 0)
return -1;
return 0;
}
static void exec_criu(struct criu_opts *opts) static void exec_criu(struct criu_opts *opts)
{ {
char **argv, log[PATH_MAX]; char **argv, log[PATH_MAX], buf[257];
int static_args = 14, argc = 0, i, ret; int static_args = 14, argc = 0, i, ret;
int netnr = 0;
struct lxc_list *it;
/* The command line always looks like: /* The command line always looks like:
* criu $(action) --tcp-established --file-locks --link-remap --force-irmap \ * criu $(action) --tcp-established --file-locks --link-remap --force-irmap \
...@@ -3648,9 +3624,6 @@ static void exec_criu(struct criu_opts *opts) ...@@ -3648,9 +3624,6 @@ static void exec_criu(struct criu_opts *opts)
if (!opts->stop) if (!opts->stop)
DECLARE_ARG("--leave-running"); DECLARE_ARG("--leave-running");
} else if (strcmp(opts->action, "restore") == 0) { } else if (strcmp(opts->action, "restore") == 0) {
int netnr = 0;
struct lxc_list *it;
DECLARE_ARG("--root"); DECLARE_ARG("--root");
DECLARE_ARG(opts->c->lxc_conf->rootfs.mount); DECLARE_ARG(opts->c->lxc_conf->rootfs.mount);
DECLARE_ARG("--restore-detached"); DECLARE_ARG("--restore-detached");
...@@ -3661,18 +3634,24 @@ static void exec_criu(struct criu_opts *opts) ...@@ -3661,18 +3634,24 @@ static void exec_criu(struct criu_opts *opts)
DECLARE_ARG(opts->cgroup_path); DECLARE_ARG(opts->cgroup_path);
lxc_list_for_each(it, &opts->c->lxc_conf->network) { lxc_list_for_each(it, &opts->c->lxc_conf->network) {
char eth[128], veth[128], buf[257]; char eth[128], *veth;
void *m; void *m;
struct lxc_netdev *n = it->elem;
if (n->name) {
if (strlen(n->name) >= 128)
goto err;
strncpy(eth, n->name, 128);
} else
sprintf(eth, "eth%d", netnr);
veth = n->priv.veth_attr.pair;
if (read_criu_file(opts->directory, "veth", netnr, veth))
goto err;
if (read_criu_file(opts->directory, "eth", netnr, eth))
goto err;
ret = snprintf(buf, 257, "%s=%s", eth, veth); ret = snprintf(buf, 257, "%s=%s", eth, veth);
if (ret < 0 || ret >= 257) if (ret < 0 || ret >= 257)
goto err; goto err;
/* final NULL and --veth-pair eth0:vethASDF */ /* final NULL and --veth-pair eth0=vethASDF */
m = realloc(argv, (argc + 1 + 2) * sizeof(*argv)); m = realloc(argv, (argc + 1 + 2) * sizeof(*argv));
if (!m) if (!m)
goto err; goto err;
...@@ -3682,12 +3661,43 @@ static void exec_criu(struct criu_opts *opts) ...@@ -3682,12 +3661,43 @@ static void exec_criu(struct criu_opts *opts)
DECLARE_ARG(buf); DECLARE_ARG(buf);
argv[argc] = NULL; argv[argc] = NULL;
netnr++;
} }
} }
#undef DECLARE_ARG netnr = 0;
lxc_list_for_each(it, &opts->c->lxc_conf->network) {
struct lxc_netdev *n = it->elem;
char veth[128];
/*
* Here, we set some parameters that lxc-restore-net
* will examine to figure out the right network to
* restore.
*/
snprintf(buf, sizeof(buf), "LXC_CRIU_BRIDGE%d", netnr);
if (setenv(buf, n->link, 1))
goto err;
if (strcmp("restore", opts->action) == 0)
strncpy(veth, n->priv.veth_attr.pair, sizeof(veth));
else {
char *tmp;
ret = snprintf(buf, sizeof(buf), "lxc.network.%d.veth.pair", netnr);
if (ret < 0 || ret >= sizeof(buf))
goto err;
tmp = lxcapi_get_running_config_item(opts->c, buf);
strncpy(veth, tmp, sizeof(veth));
free(tmp);
}
snprintf(buf, sizeof(buf), "LXC_CRIU_VETH%d", netnr);
if (setenv(buf, veth, 1))
goto err;
netnr++;
}
#undef DECLARE_ARG
execv(argv[0], argv); execv(argv[0], argv);
err: err:
for (i = 0; argv[i]; i++) for (i = 0; argv[i]; i++)
...@@ -3771,10 +3781,6 @@ static bool dump_net_info(struct lxc_container *c, char *directory) ...@@ -3771,10 +3781,6 @@ static bool dump_net_info(struct lxc_container *c, char *directory)
break; break;
} }
pret = snprintf(veth_path, PATH_MAX, "lxc.network.%d.link", netnr);
if (pret < 0 || pret >= PATH_MAX)
goto out;
bridge = lxcapi_get_running_config_item(c, veth_path); bridge = lxcapi_get_running_config_item(c, veth_path);
if (!bridge) if (!bridge)
goto out; goto out;
...@@ -3783,10 +3789,6 @@ static bool dump_net_info(struct lxc_container *c, char *directory) ...@@ -3783,10 +3789,6 @@ static bool dump_net_info(struct lxc_container *c, char *directory)
if (pret < 0 || pret >= PATH_MAX || print_to_file(veth_path, veth) < 0) if (pret < 0 || pret >= PATH_MAX || print_to_file(veth_path, veth) < 0)
goto out; goto out;
pret = snprintf(veth_path, PATH_MAX, "%s/bridge%d", directory, netnr);
if (pret < 0 || pret >= PATH_MAX || print_to_file(veth_path, bridge) < 0)
goto out;
if (n->name) { if (n->name) {
if (strlen(n->name) >= 128) if (strlen(n->name) >= 128)
goto out; goto out;
...@@ -3794,10 +3796,6 @@ static bool dump_net_info(struct lxc_container *c, char *directory) ...@@ -3794,10 +3796,6 @@ static bool dump_net_info(struct lxc_container *c, char *directory)
} else } else
sprintf(eth, "eth%d", netnr); sprintf(eth, "eth%d", netnr);
pret = snprintf(veth_path, PATH_MAX, "%s/eth%d", directory, netnr);
if (pret < 0 || pret >= PATH_MAX || print_to_file(veth_path, eth) < 0)
goto out;
has_error = false; has_error = false;
out: out:
if (veth) if (veth)
...@@ -3856,30 +3854,24 @@ static bool lxcapi_checkpoint(struct lxc_container *c, char *directory, bool sto ...@@ -3856,30 +3854,24 @@ static bool lxcapi_checkpoint(struct lxc_container *c, char *directory, bool sto
} }
} }
static bool restore_net_info(struct lxc_container *c, char *directory) static bool restore_net_info(struct lxc_container *c)
{ {
struct lxc_list *it; struct lxc_list *it;
bool has_error = true; bool has_error = true;
int netnr = 0;
if (container_mem_lock(c)) if (container_mem_lock(c))
return false; return false;
lxc_list_for_each(it, &c->lxc_conf->network) { lxc_list_for_each(it, &c->lxc_conf->network) {
char eth[128], veth[128];
struct lxc_netdev *netdev = it->elem; struct lxc_netdev *netdev = it->elem;
char template[IFNAMSIZ];
snprintf(template, sizeof(template), "vethXXXXXX");
if (read_criu_file(directory, "veth", netnr, veth)) if (!netdev->priv.veth_attr.pair)
goto out_unlock; netdev->priv.veth_attr.pair = lxc_mkifname(template);
if (read_criu_file(directory, "eth", netnr, eth))
goto out_unlock;
netdev->priv.veth_attr.pair = strdup(veth);
if (!netdev->priv.veth_attr.pair) if (!netdev->priv.veth_attr.pair)
goto out_unlock; goto out_unlock;
netnr++;
} }
has_error = false; has_error = false;
...@@ -3922,6 +3914,11 @@ static bool lxcapi_restore(struct lxc_container *c, char *directory, bool verbos ...@@ -3922,6 +3914,11 @@ static bool lxcapi_restore(struct lxc_container *c, char *directory, bool verbos
goto out_fini_handler; goto out_fini_handler;
} }
if (!restore_net_info(c)) {
ERROR("failed restoring network info");
goto out_fini_handler;
}
pid = fork(); pid = fork();
if (pid < 0) if (pid < 0)
goto out_fini_handler; goto out_fini_handler;
...@@ -3992,11 +3989,6 @@ static bool lxcapi_restore(struct lxc_container *c, char *directory, bool verbos ...@@ -3992,11 +3989,6 @@ static bool lxcapi_restore(struct lxc_container *c, char *directory, bool verbos
goto out_fini_handler; goto out_fini_handler;
} }
if (!restore_net_info(c, directory)) {
ERROR("failed restoring network info");
goto out_fini_handler;
}
if (lxc_set_state(c->name, handler, RUNNING)) if (lxc_set_state(c->name, handler, RUNNING))
goto out_fini_handler; goto out_fini_handler;
} }
......
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