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-rw-r--r--tools/testing/selftests/bpf/netlink_helpers.c358
1 files changed, 358 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/netlink_helpers.c b/tools/testing/selftests/bpf/netlink_helpers.c
new file mode 100644
index 0000000000..caf36eb1d0
--- /dev/null
+++ b/tools/testing/selftests/bpf/netlink_helpers.c
@@ -0,0 +1,358 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Taken & modified from iproute2's libnetlink.c
+ * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <time.h>
+#include <sys/socket.h>
+
+#include "netlink_helpers.h"
+
+static int rcvbuf = 1024 * 1024;
+
+void rtnl_close(struct rtnl_handle *rth)
+{
+ if (rth->fd >= 0) {
+ close(rth->fd);
+ rth->fd = -1;
+ }
+}
+
+int rtnl_open_byproto(struct rtnl_handle *rth, unsigned int subscriptions,
+ int protocol)
+{
+ socklen_t addr_len;
+ int sndbuf = 32768;
+ int one = 1;
+
+ memset(rth, 0, sizeof(*rth));
+ rth->proto = protocol;
+ rth->fd = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, protocol);
+ if (rth->fd < 0) {
+ perror("Cannot open netlink socket");
+ return -1;
+ }
+ if (setsockopt(rth->fd, SOL_SOCKET, SO_SNDBUF,
+ &sndbuf, sizeof(sndbuf)) < 0) {
+ perror("SO_SNDBUF");
+ goto err;
+ }
+ if (setsockopt(rth->fd, SOL_SOCKET, SO_RCVBUF,
+ &rcvbuf, sizeof(rcvbuf)) < 0) {
+ perror("SO_RCVBUF");
+ goto err;
+ }
+
+ /* Older kernels may no support extended ACK reporting */
+ setsockopt(rth->fd, SOL_NETLINK, NETLINK_EXT_ACK,
+ &one, sizeof(one));
+
+ memset(&rth->local, 0, sizeof(rth->local));
+ rth->local.nl_family = AF_NETLINK;
+ rth->local.nl_groups = subscriptions;
+
+ if (bind(rth->fd, (struct sockaddr *)&rth->local,
+ sizeof(rth->local)) < 0) {
+ perror("Cannot bind netlink socket");
+ goto err;
+ }
+ addr_len = sizeof(rth->local);
+ if (getsockname(rth->fd, (struct sockaddr *)&rth->local,
+ &addr_len) < 0) {
+ perror("Cannot getsockname");
+ goto err;
+ }
+ if (addr_len != sizeof(rth->local)) {
+ fprintf(stderr, "Wrong address length %d\n", addr_len);
+ goto err;
+ }
+ if (rth->local.nl_family != AF_NETLINK) {
+ fprintf(stderr, "Wrong address family %d\n",
+ rth->local.nl_family);
+ goto err;
+ }
+ rth->seq = time(NULL);
+ return 0;
+err:
+ rtnl_close(rth);
+ return -1;
+}
+
+int rtnl_open(struct rtnl_handle *rth, unsigned int subscriptions)
+{
+ return rtnl_open_byproto(rth, subscriptions, NETLINK_ROUTE);
+}
+
+static int __rtnl_recvmsg(int fd, struct msghdr *msg, int flags)
+{
+ int len;
+
+ do {
+ len = recvmsg(fd, msg, flags);
+ } while (len < 0 && (errno == EINTR || errno == EAGAIN));
+ if (len < 0) {
+ fprintf(stderr, "netlink receive error %s (%d)\n",
+ strerror(errno), errno);
+ return -errno;
+ }
+ if (len == 0) {
+ fprintf(stderr, "EOF on netlink\n");
+ return -ENODATA;
+ }
+ return len;
+}
+
+static int rtnl_recvmsg(int fd, struct msghdr *msg, char **answer)
+{
+ struct iovec *iov = msg->msg_iov;
+ char *buf;
+ int len;
+
+ iov->iov_base = NULL;
+ iov->iov_len = 0;
+
+ len = __rtnl_recvmsg(fd, msg, MSG_PEEK | MSG_TRUNC);
+ if (len < 0)
+ return len;
+ if (len < 32768)
+ len = 32768;
+ buf = malloc(len);
+ if (!buf) {
+ fprintf(stderr, "malloc error: not enough buffer\n");
+ return -ENOMEM;
+ }
+ iov->iov_base = buf;
+ iov->iov_len = len;
+ len = __rtnl_recvmsg(fd, msg, 0);
+ if (len < 0) {
+ free(buf);
+ return len;
+ }
+ if (answer)
+ *answer = buf;
+ else
+ free(buf);
+ return len;
+}
+
+static void rtnl_talk_error(struct nlmsghdr *h, struct nlmsgerr *err,
+ nl_ext_ack_fn_t errfn)
+{
+ fprintf(stderr, "RTNETLINK answers: %s\n",
+ strerror(-err->error));
+}
+
+static int __rtnl_talk_iov(struct rtnl_handle *rtnl, struct iovec *iov,
+ size_t iovlen, struct nlmsghdr **answer,
+ bool show_rtnl_err, nl_ext_ack_fn_t errfn)
+{
+ struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
+ struct iovec riov;
+ struct msghdr msg = {
+ .msg_name = &nladdr,
+ .msg_namelen = sizeof(nladdr),
+ .msg_iov = iov,
+ .msg_iovlen = iovlen,
+ };
+ unsigned int seq = 0;
+ struct nlmsghdr *h;
+ int i, status;
+ char *buf;
+
+ for (i = 0; i < iovlen; i++) {
+ h = iov[i].iov_base;
+ h->nlmsg_seq = seq = ++rtnl->seq;
+ if (answer == NULL)
+ h->nlmsg_flags |= NLM_F_ACK;
+ }
+ status = sendmsg(rtnl->fd, &msg, 0);
+ if (status < 0) {
+ perror("Cannot talk to rtnetlink");
+ return -1;
+ }
+ /* change msg to use the response iov */
+ msg.msg_iov = &riov;
+ msg.msg_iovlen = 1;
+ i = 0;
+ while (1) {
+next:
+ status = rtnl_recvmsg(rtnl->fd, &msg, &buf);
+ ++i;
+ if (status < 0)
+ return status;
+ if (msg.msg_namelen != sizeof(nladdr)) {
+ fprintf(stderr,
+ "Sender address length == %d!\n",
+ msg.msg_namelen);
+ exit(1);
+ }
+ for (h = (struct nlmsghdr *)buf; status >= sizeof(*h); ) {
+ int len = h->nlmsg_len;
+ int l = len - sizeof(*h);
+
+ if (l < 0 || len > status) {
+ if (msg.msg_flags & MSG_TRUNC) {
+ fprintf(stderr, "Truncated message!\n");
+ free(buf);
+ return -1;
+ }
+ fprintf(stderr,
+ "Malformed message: len=%d!\n",
+ len);
+ exit(1);
+ }
+ if (nladdr.nl_pid != 0 ||
+ h->nlmsg_pid != rtnl->local.nl_pid ||
+ h->nlmsg_seq > seq || h->nlmsg_seq < seq - iovlen) {
+ /* Don't forget to skip that message. */
+ status -= NLMSG_ALIGN(len);
+ h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
+ continue;
+ }
+ if (h->nlmsg_type == NLMSG_ERROR) {
+ struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
+ int error = err->error;
+
+ if (l < sizeof(struct nlmsgerr)) {
+ fprintf(stderr, "ERROR truncated\n");
+ free(buf);
+ return -1;
+ }
+ if (error) {
+ errno = -error;
+ if (rtnl->proto != NETLINK_SOCK_DIAG &&
+ show_rtnl_err)
+ rtnl_talk_error(h, err, errfn);
+ }
+ if (i < iovlen) {
+ free(buf);
+ goto next;
+ }
+ if (error) {
+ free(buf);
+ return -i;
+ }
+ if (answer)
+ *answer = (struct nlmsghdr *)buf;
+ else
+ free(buf);
+ return 0;
+ }
+ if (answer) {
+ *answer = (struct nlmsghdr *)buf;
+ return 0;
+ }
+ fprintf(stderr, "Unexpected reply!\n");
+ status -= NLMSG_ALIGN(len);
+ h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
+ }
+ free(buf);
+ if (msg.msg_flags & MSG_TRUNC) {
+ fprintf(stderr, "Message truncated!\n");
+ continue;
+ }
+ if (status) {
+ fprintf(stderr, "Remnant of size %d!\n", status);
+ exit(1);
+ }
+ }
+}
+
+static int __rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
+ struct nlmsghdr **answer, bool show_rtnl_err,
+ nl_ext_ack_fn_t errfn)
+{
+ struct iovec iov = {
+ .iov_base = n,
+ .iov_len = n->nlmsg_len,
+ };
+
+ return __rtnl_talk_iov(rtnl, &iov, 1, answer, show_rtnl_err, errfn);
+}
+
+int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
+ struct nlmsghdr **answer)
+{
+ return __rtnl_talk(rtnl, n, answer, true, NULL);
+}
+
+int addattr(struct nlmsghdr *n, int maxlen, int type)
+{
+ return addattr_l(n, maxlen, type, NULL, 0);
+}
+
+int addattr8(struct nlmsghdr *n, int maxlen, int type, __u8 data)
+{
+ return addattr_l(n, maxlen, type, &data, sizeof(__u8));
+}
+
+int addattr16(struct nlmsghdr *n, int maxlen, int type, __u16 data)
+{
+ return addattr_l(n, maxlen, type, &data, sizeof(__u16));
+}
+
+int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
+{
+ return addattr_l(n, maxlen, type, &data, sizeof(__u32));
+}
+
+int addattr64(struct nlmsghdr *n, int maxlen, int type, __u64 data)
+{
+ return addattr_l(n, maxlen, type, &data, sizeof(__u64));
+}
+
+int addattrstrz(struct nlmsghdr *n, int maxlen, int type, const char *str)
+{
+ return addattr_l(n, maxlen, type, str, strlen(str)+1);
+}
+
+int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
+ int alen)
+{
+ int len = RTA_LENGTH(alen);
+ struct rtattr *rta;
+
+ if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
+ fprintf(stderr, "%s: Message exceeded bound of %d\n",
+ __func__, maxlen);
+ return -1;
+ }
+ rta = NLMSG_TAIL(n);
+ rta->rta_type = type;
+ rta->rta_len = len;
+ if (alen)
+ memcpy(RTA_DATA(rta), data, alen);
+ n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
+ return 0;
+}
+
+int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len)
+{
+ if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) {
+ fprintf(stderr, "%s: Message exceeded bound of %d\n",
+ __func__, maxlen);
+ return -1;
+ }
+
+ memcpy(NLMSG_TAIL(n), data, len);
+ memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len);
+ n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len);
+ return 0;
+}
+
+struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type)
+{
+ struct rtattr *nest = NLMSG_TAIL(n);
+
+ addattr_l(n, maxlen, type, NULL, 0);
+ return nest;
+}
+
+int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest)
+{
+ nest->rta_len = (void *)NLMSG_TAIL(n) - (void *)nest;
+ return n->nlmsg_len;
+}
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