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Commit ae22a220 by S.Çağlar Onur Committed by Stéphane Graber
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make lxcapi_get_interfaces and lxcapi_get_ips unprivileged container aware

Based on Stéphane's suggestion, those two API methods now; * fork a new process, * switch to appropriate namespace(s), * do what we want, * return the data over a pipe to the parent which returns the result to the original caller. For the whole thread please see; https://lists.linuxcontainers.org/pipermail/lxc-devel/2014-January/007362.html This patch also makes lxc-ls and lxc-info call those functions. I'm adding Stéphane as an author here since both the idea as well as the initial setns code come from him. Author: S.Çağlar Onur <caglar@10ur.org> Author: Stéphane Graber <stgraber@ubuntu.com> Signed-off-by: 's avatarS.Çağlar Onur <caglar@10ur.org> Acked-by: 's avatarStéphane Graber <stgraber@ubuntu.com> Acked-by: 's avatarSerge E. Hallyn <serge.hallyn@ubuntu.com>
parent adf4b408
Showing with 186 additions and 116 deletions
src/lxc/lxc-ls
......@@ -265,7 +265,7 @@ for container_name in lxc.list_containers(config_path=nest_lxcpath):
# FIXME: We should get get_ips working as non-root
if container.running:
if not SUPPORT_SETNS_NET or os.geteuid() != 0:
if not SUPPORT_SETNS_NET:
entry[protocol] = 'UNKNOWN'
continue
......
src/lxc/lxc_info.c
......@@ -310,19 +310,15 @@ static int print_info(const char *name, const char *lxcpath)
}
if (ips) {
if (geteuid() == 0) {
char **addresses = c->get_ips(c, NULL, NULL, 0);
if (addresses) {
char *address;
i = 0;
while (addresses[i]) {
address = addresses[i];
print_info_msg_str("IP:", address);
i++;
}
char **addresses = c->get_ips(c, NULL, NULL, 0);
if (addresses) {
char *address;
i = 0;
while (addresses[i]) {
address = addresses[i];
print_info_msg_str("IP:", address);
i++;
}
} else {
print_info_msg_str("IP:", "UNKNOWN");
}
}
......
src/lxc/lxccontainer.c
......@@ -1372,48 +1372,51 @@ static bool lxcapi_clear_config_item(struct lxc_container *c, const char *key)
return ret == 0;
}
static inline void exit_from_ns(struct lxc_container *c, int *old_netns, int *new_netns) {
/* Switch back to original netns */
if (*old_netns >= 0 && setns(*old_netns, CLONE_NEWNET))
SYSERROR("failed to setns");
if (*new_netns >= 0)
close(*new_netns);
if (*old_netns >= 0)
close(*old_netns);
}
static inline bool enter_to_ns(struct lxc_container *c, int *old_netns, int *new_netns) {
int ret = 0;
static inline bool enter_to_ns(struct lxc_container *c) {
int netns, userns, ret = 0, init_pid = 0;;
char new_netns_path[MAXPATHLEN];
char new_userns_path[MAXPATHLEN];
if (!c->is_running(c))
goto out;
/* Save reference to old netns */
*old_netns = open("/proc/self/ns/net", O_RDONLY);
if (*old_netns < 0) {
SYSERROR("failed to open /proc/self/ns/net");
goto out;
init_pid = c->init_pid(c);
/* Switch to new userns */
if (geteuid() && access("/proc/self/ns/user", F_OK) == 0) {
ret = snprintf(new_userns_path, MAXPATHLEN, "/proc/%d/ns/user", init_pid);
if (ret < 0 || ret >= MAXPATHLEN)
goto out;
userns = open(new_userns_path, O_RDONLY);
if (userns < 0) {
SYSERROR("failed to open %s", new_userns_path);
goto out;
}
if (setns(userns, CLONE_NEWUSER)) {
SYSERROR("failed to setns for CLONE_NEWUSER");
goto out;
}
}
/* Switch to new netns */
ret = snprintf(new_netns_path, MAXPATHLEN, "/proc/%d/ns/net", c->init_pid(c));
ret = snprintf(new_netns_path, MAXPATHLEN, "/proc/%d/ns/net", init_pid);
if (ret < 0 || ret >= MAXPATHLEN)
goto out;
*new_netns = open(new_netns_path, O_RDONLY);
if (*new_netns < 0) {
netns = open(new_netns_path, O_RDONLY);
if (netns < 0) {
SYSERROR("failed to open %s", new_netns_path);
goto out;
}
if (setns(*new_netns, CLONE_NEWNET)) {
SYSERROR("failed to setns");
if (setns(netns, CLONE_NEWNET)) {
SYSERROR("failed to setns for CLONE_NEWNET");
goto out;
}
return true;
out:
exit_from_ns(c, old_netns, new_netns);
return false;
}
......@@ -1490,135 +1493,206 @@ static bool remove_from_array(char ***names, char *cname, int size)
static char** lxcapi_get_interfaces(struct lxc_container *c)
{
int i, count = 0;
struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;
pid_t pid;
int i, count = 0, pipefd[2];
char **interfaces = NULL;
int old_netns = -1, new_netns = -1;
char interface[IFNAMSIZ];
if (am_unpriv()) {
ERROR(NOT_SUPPORTED_ERROR, __FUNCTION__);
goto out;
if(pipe(pipefd) < 0) {
SYSERROR("pipe failed");
return NULL;
}
if (!enter_to_ns(c, &old_netns, &new_netns))
goto out;
pid = fork();
if (pid < 0) {
SYSERROR("failed to fork task to get interfaces information\n");
close(pipefd[0]);
close(pipefd[1]);
return NULL;
}
/* Grab the list of interfaces */
if (getifaddrs(&interfaceArray)) {
SYSERROR("failed to get interfaces list");
goto out;
if (pid == 0) { // child
int ret = 1, nbytes;
struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;
/* close the read-end of the pipe */
close(pipefd[0]);
if (!enter_to_ns(c)) {
SYSERROR("failed to enter namespace");
goto out;
}
/* Grab the list of interfaces */
if (getifaddrs(&interfaceArray)) {
SYSERROR("failed to get interfaces list");
goto out;
}
/* Iterate through the interfaces */
for (tempIfAddr = interfaceArray; tempIfAddr != NULL; tempIfAddr = tempIfAddr->ifa_next) {
nbytes = write(pipefd[1], tempIfAddr->ifa_name, IFNAMSIZ);
if (nbytes < 0) {
ERROR("write failed");
goto out;
}
count++;
}
ret = 0;
out:
if (interfaceArray)
freeifaddrs(interfaceArray);
/* close the write-end of the pipe, thus sending EOF to the reader */
close(pipefd[1]);
exit(ret);
}
/* Iterate through the interfaces */
for (tempIfAddr = interfaceArray; tempIfAddr != NULL; tempIfAddr = tempIfAddr->ifa_next) {
if (array_contains(&interfaces, tempIfAddr->ifa_name, count))
continue;
/* close the write-end of the pipe */
close(pipefd[1]);
if(!add_to_array(&interfaces, tempIfAddr->ifa_name, count))
goto err;
while (read(pipefd[0], &interface, IFNAMSIZ) > 0) {
if (array_contains(&interfaces, interface, count))
continue;
if(!add_to_array(&interfaces, interface, count))
ERROR("PARENT: add_to_array failed");
count++;
}
out:
if (interfaceArray)
freeifaddrs(interfaceArray);
if (wait_for_pid(pid) != 0) {
for(i=0;i<count;i++)
free(interfaces[i]);
free(interfaces);
interfaces = NULL;
}
exit_from_ns(c, &old_netns, &new_netns);
/* close the read-end of the pipe */
close(pipefd[0]);
/* Append NULL to the array */
if(interfaces)
interfaces = (char **)lxc_append_null_to_array((void **)interfaces, count);
return interfaces;
err:
for(i=0;i<count;i++)
free(interfaces[i]);
free(interfaces);
interfaces = NULL;
goto out;
}
static char** lxcapi_get_ips(struct lxc_container *c, const char* interface, const char* family, int scope)
{
int i, count = 0;
struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;
char addressOutputBuffer[INET6_ADDRSTRLEN];
void *tempAddrPtr = NULL;
pid_t pid;
int i, count = 0, pipefd[2];
char **addresses = NULL;
char *address = NULL;
int old_netns = -1, new_netns = -1;
char address[INET6_ADDRSTRLEN];
if (am_unpriv()) {
ERROR(NOT_SUPPORTED_ERROR, __FUNCTION__);
goto out;
if(pipe(pipefd) < 0) {
SYSERROR("pipe failed");
return NULL;
}
if (!enter_to_ns(c, &old_netns, &new_netns))
goto out;
/* Grab the list of interfaces */
if (getifaddrs(&interfaceArray)) {
SYSERROR("failed to get interfaces list");
goto out;
pid = fork();
if (pid < 0) {
SYSERROR("failed to fork task to get container ips\n");
close(pipefd[0]);
close(pipefd[1]);
return NULL;
}
/* Iterate through the interfaces */
for (tempIfAddr = interfaceArray; tempIfAddr != NULL; tempIfAddr = tempIfAddr->ifa_next) {
if (tempIfAddr->ifa_addr == NULL)
continue;
if (pid == 0) { // child
int ret = 1, nbytes;
struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;
char addressOutputBuffer[INET6_ADDRSTRLEN];
void *tempAddrPtr = NULL;
char *address = NULL;
if(tempIfAddr->ifa_addr->sa_family == AF_INET) {
if (family && strcmp(family, "inet"))
continue;
tempAddrPtr = &((struct sockaddr_in *)tempIfAddr->ifa_addr)->sin_addr;
/* close the read-end of the pipe */
close(pipefd[0]);
if (!enter_to_ns(c)) {
SYSERROR("failed to enter namespace");
goto out;
}
else {
if (family && strcmp(family, "inet6"))
/* Grab the list of interfaces */
if (getifaddrs(&interfaceArray)) {
SYSERROR("failed to get interfaces list");
goto out;
}
/* Iterate through the interfaces */
for (tempIfAddr = interfaceArray; tempIfAddr != NULL; tempIfAddr = tempIfAddr->ifa_next) {
if (tempIfAddr->ifa_addr == NULL)
continue;
if (((struct sockaddr_in6 *)tempIfAddr->ifa_addr)->sin6_scope_id != scope)
if(tempIfAddr->ifa_addr->sa_family == AF_INET) {
if (family && strcmp(family, "inet"))
continue;
tempAddrPtr = &((struct sockaddr_in *)tempIfAddr->ifa_addr)->sin_addr;
}
else {
if (family && strcmp(family, "inet6"))
continue;
if (((struct sockaddr_in6 *)tempIfAddr->ifa_addr)->sin6_scope_id != scope)
continue;
tempAddrPtr = &((struct sockaddr_in6 *)tempIfAddr->ifa_addr)->sin6_addr;
}
if (interface && strcmp(interface, tempIfAddr->ifa_name))
continue;
else if (!interface && strcmp("lo", tempIfAddr->ifa_name) == 0)
continue;
tempAddrPtr = &((struct sockaddr_in6 *)tempIfAddr->ifa_addr)->sin6_addr;
address = (char *)inet_ntop(tempIfAddr->ifa_addr->sa_family,
tempAddrPtr,
addressOutputBuffer,
sizeof(addressOutputBuffer));
if (!address)
continue;
nbytes = write(pipefd[1], address, INET6_ADDRSTRLEN);
if (nbytes < 0) {
ERROR("write failed");
goto out;
}
count++;
}
ret = 0;
if (interface && strcmp(interface, tempIfAddr->ifa_name))
continue;
else if (!interface && strcmp("lo", tempIfAddr->ifa_name) == 0)
continue;
out:
if(interfaceArray)
freeifaddrs(interfaceArray);
address = (char *)inet_ntop(tempIfAddr->ifa_addr->sa_family,
tempAddrPtr,
addressOutputBuffer,
sizeof(addressOutputBuffer));
if (!address)
continue;
/* close the write-end of the pipe, thus sending EOF to the reader */
close(pipefd[1]);
exit(ret);
}
/* close the write-end of the pipe */
close(pipefd[1]);
while (read(pipefd[0], &address, INET6_ADDRSTRLEN) > 0) {
if(!add_to_array(&addresses, address, count))
goto err;
ERROR("PARENT: add_to_array failed");
count++;
}
out:
if(interfaceArray)
freeifaddrs(interfaceArray);
if (wait_for_pid(pid) != 0) {
for(i=0;i<count;i++)
free(addresses[i]);
free(addresses);
addresses = NULL;
}
exit_from_ns(c, &old_netns, &new_netns);
/* close the read-end of the pipe */
close(pipefd[0]);
/* Append NULL to the array */
if(addresses)
addresses = (char **)lxc_append_null_to_array((void **)addresses, count);
return addresses;
err:
for(i=0;i<count;i++)
free(addresses[i]);
free(addresses);
addresses = NULL;
goto out;
}
static int lxcapi_get_config_item(struct lxc_container *c, const char *key, char *retv, int inlen)
......
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