along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
-#include <errno.h>
#include <sys/socket.h>
#include <net/if.h>
#include <asm/types.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
-#include <linux/netlink.h>
-#include <linux/rtnetlink.h>
#include "util.h"
#include "macro.h"
#include "loopback-setup.h"
#include "socket-util.h"
+#include "sd-rtnl.h"
+#include "rtnl-util.h"
-#define NLMSG_TAIL(nmsg) \
- ((struct rtattr *) (((uint8_t*) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
+/* this is hardcoded in the kernel, so don't look it up */
+#define LOOPBACK_IFINDEX 1
-static int add_rtattr(struct nlmsghdr *n, size_t max_length, int type, const void *data, size_t data_length) {
- size_t length;
- struct rtattr *rta;
-
- length = RTA_LENGTH(data_length);
-
- if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(length) > max_length)
- return -E2BIG;
-
- rta = NLMSG_TAIL(n);
- rta->rta_type = type;
- rta->rta_len = length;
- memcpy(RTA_DATA(rta), data, data_length);
- n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(length);
-
- return 0;
-}
-
-static ssize_t sendto_loop(int fd, const void *buf, size_t buf_len, int flags, const struct sockaddr *sa, socklen_t sa_len) {
-
- for (;;) {
- ssize_t l;
-
- l = sendto(fd, buf, buf_len, flags, sa, sa_len);
- if (l >= 0)
- return l;
-
- if (errno != EINTR)
- return -errno;
- }
-}
-
-static ssize_t recvfrom_loop(int fd, void *buf, size_t buf_len, int flags, struct sockaddr *sa, socklen_t *sa_len) {
-
- for (;;) {
- ssize_t l;
-
- l = recvfrom(fd, buf, buf_len, flags, sa, sa_len);
- if (l >= 0)
- return l;
-
- if (errno != EINTR)
- return -errno;
- }
-}
-
-static int add_adresses(int fd, int if_loopback, unsigned *requests) {
- union {
- struct sockaddr sa;
- struct sockaddr_nl nl;
- } sa;
- union {
- struct nlmsghdr header;
- uint8_t buf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
- NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
- RTA_LENGTH(sizeof(struct in6_addr))];
- } request;
-
- struct ifaddrmsg *ifaddrmsg;
- uint32_t ipv4_address = htonl(INADDR_LOOPBACK);
+static int start_loopback(sd_rtnl *rtnl) {
+ _cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL;
int r;
- zero(request);
-
- request.header.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
- request.header.nlmsg_type = RTM_NEWADDR;
- request.header.nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE|NLM_F_ACK;
- request.header.nlmsg_seq = *requests + 1;
-
- ifaddrmsg = NLMSG_DATA(&request.header);
- ifaddrmsg->ifa_family = AF_INET;
- ifaddrmsg->ifa_prefixlen = 8;
- ifaddrmsg->ifa_flags = IFA_F_PERMANENT;
- ifaddrmsg->ifa_scope = RT_SCOPE_HOST;
- ifaddrmsg->ifa_index = if_loopback;
-
- r = add_rtattr(&request.header, sizeof(request), IFA_LOCAL, &ipv4_address, sizeof(ipv4_address));
+ r = sd_rtnl_message_new_link(rtnl, &req, RTM_SETLINK, LOOPBACK_IFINDEX);
if (r < 0)
return r;
- zero(sa);
- sa.nl.nl_family = AF_NETLINK;
-
- if (sendto_loop(fd, &request, request.header.nlmsg_len, 0, &sa.sa, sizeof(sa)) < 0)
- return -errno;
- (*requests)++;
-
- if (!socket_ipv6_is_supported())
- return 0;
-
- request.header.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
- request.header.nlmsg_seq = *requests + 1;
-
- ifaddrmsg->ifa_family = AF_INET6;
- ifaddrmsg->ifa_prefixlen = 128;
-
- r = add_rtattr(&request.header, sizeof(request), IFA_LOCAL, &in6addr_loopback, sizeof(in6addr_loopback));
+ r = sd_rtnl_message_link_set_flags(req, IFF_UP, IFF_UP);
if (r < 0)
return r;
- if (sendto_loop(fd, &request, request.header.nlmsg_len, 0, &sa.sa, sizeof(sa)) < 0)
- return -errno;
- (*requests)++;
-
- return 0;
-}
-
-static int start_interface(int fd, int if_loopback, unsigned *requests) {
- union {
- struct sockaddr sa;
- struct sockaddr_nl nl;
- } sa;
- union {
- struct nlmsghdr header;
- uint8_t buf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
- NLMSG_ALIGN(sizeof(struct ifinfomsg))];
- } request;
-
- struct ifinfomsg *ifinfomsg;
-
- zero(request);
-
- request.header.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
- request.header.nlmsg_type = RTM_NEWLINK;
- request.header.nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK;
- request.header.nlmsg_seq = *requests + 1;
-
- ifinfomsg = NLMSG_DATA(&request.header);
- ifinfomsg->ifi_family = AF_UNSPEC;
- ifinfomsg->ifi_index = if_loopback;
- ifinfomsg->ifi_flags = IFF_UP;
- ifinfomsg->ifi_change = IFF_UP;
-
- zero(sa);
- sa.nl.nl_family = AF_NETLINK;
-
- if (sendto_loop(fd, &request, request.header.nlmsg_len, 0, &sa.sa, sizeof(sa)) < 0)
- return -errno;
-
- (*requests)++;
+ r = sd_rtnl_call(rtnl, req, 0, NULL);
+ if (r < 0)
+ return r;
return 0;
}
-static int read_response(int fd, unsigned requests_max) {
- union {
- struct sockaddr sa;
- struct sockaddr_nl nl;
- } sa;
- union {
- struct nlmsghdr header;
- uint8_t buf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
- NLMSG_ALIGN(sizeof(struct nlmsgerr))];
- } response;
-
- ssize_t l;
- socklen_t sa_len = sizeof(sa);
- struct nlmsgerr *nlmsgerr;
-
- l = recvfrom_loop(fd, &response, sizeof(response), 0, &sa.sa, &sa_len);
- if (l < 0)
- return -errno;
-
- if (sa_len != sizeof(sa.nl) ||
- sa.nl.nl_family != AF_NETLINK)
- return -EIO;
-
- if (sa.nl.nl_pid != 0)
- return 0;
-
- if ((size_t) l < sizeof(struct nlmsghdr))
- return -EIO;
-
- if (response.header.nlmsg_type != NLMSG_ERROR ||
- (pid_t) response.header.nlmsg_pid != getpid() ||
- response.header.nlmsg_seq >= requests_max)
- return 0;
-
- if ((size_t) l < NLMSG_LENGTH(sizeof(struct nlmsgerr)) ||
- response.header.nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
- return -EIO;
-
- nlmsgerr = NLMSG_DATA(&response.header);
-
- if (nlmsgerr->error < 0 && nlmsgerr->error != -EEXIST)
- return nlmsgerr->error;
-
- return response.header.nlmsg_seq;
-}
-
-static int check_loopback(void) {
- int r, fd;
- union {
- struct sockaddr sa;
- struct sockaddr_in in;
- } sa;
-
- /* If we failed to set up the loop back device, check whether
- * it might already be set up */
-
- fd = socket(AF_INET, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
- if (fd < 0)
- return -errno;
+static bool check_loopback(sd_rtnl *rtnl) {
+ _cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL, *reply = NULL;
+ unsigned flags;
+ int r;
- zero(sa);
- sa.in.sin_family = AF_INET;
- sa.in.sin_addr.s_addr = INADDR_LOOPBACK;
+ r = sd_rtnl_message_new_link(rtnl, &req, RTM_GETLINK, LOOPBACK_IFINDEX);
+ if (r < 0)
+ return false;
- if (bind(fd, &sa.sa, sizeof(sa.in)) >= 0)
- r = 1;
- else
- r = errno == EADDRNOTAVAIL ? 0 : -errno;
+ r = sd_rtnl_call(rtnl, req, 0, &reply);
+ if (r < 0)
+ return false;
- close_nointr_nofail(fd);
+ r = sd_rtnl_message_link_get_flags(reply, &flags);
+ if (r < 0)
+ return false;
- return r;
+ return flags & IFF_UP;
}
int loopback_setup(void) {
- int r, if_loopback;
- union {
- struct sockaddr sa;
- struct sockaddr_nl nl;
- } sa;
- unsigned requests = 0, i;
- int fd;
- bool eperm = false;
-
- errno = 0;
- if_loopback = (int) if_nametoindex("lo");
- if (if_loopback <= 0)
- return errno ? -errno : -ENODEV;
-
- fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
- if (fd < 0)
- return -errno;
-
- zero(sa);
- sa.nl.nl_family = AF_NETLINK;
- if (bind(fd, &sa.sa, sizeof(sa)) < 0) {
- r = -errno;
- goto finish;
- }
-
- r = add_adresses(fd, if_loopback, &requests);
- if (r < 0)
- goto finish;
+ _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
+ int r;
- r = start_interface(fd, if_loopback, &requests);
+ r = sd_rtnl_open(&rtnl, 0);
if (r < 0)
- goto finish;
-
- for (i = 0; i < requests; i++) {
- r = read_response(fd, requests);
-
- if (r == -EPERM)
- eperm = true;
- else if (r < 0)
- goto finish;
- }
-
- if (eperm && check_loopback() < 0) {
- r = -EPERM;
- goto finish;
- }
-
- r = 0;
+ return r;
-finish:
- if (r < 0)
- log_warning("Failed to configure loopback device: %s", strerror(-r));
+ r = start_loopback(rtnl);
+ if (r == -EPERM) {
+ if (!check_loopback(rtnl))
+ return log_warning_errno(EPERM, "Failed to configure loopback device: %m");
+ } else if (r < 0)
+ return log_warning_errno(r, "Failed to configure loopback device: %m");
- if (fd >= 0)
- close_nointr_nofail(fd);
- return r;
+ return 0;
}
~ianmdlvl / elogind.git / blobdiff