Cleanroom libnl_2 library
By overriding the netlink cache pointer, able to pass nl80211 family id.
Scan and connecting open access point work
Added legal stuff to headers
Change-Id: I1c60452f35fdd1f80edebc03fef33067722d0543
diff --git a/libnl_2/netlink.c b/libnl_2/netlink.c
new file mode 100644
index 0000000..cc2f88e
--- /dev/null
+++ b/libnl_2/netlink.c
@@ -0,0 +1,273 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* NOTICE: This is a clean room re-implementation of libnl */
+
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include "netlink-types.h"
+
+#define NL_BUFFER_SZ (32768U)
+
+/* Checks message for completeness and sends it out */
+int nl_send_auto_complete(struct nl_sock *sk, struct nl_msg *msg)
+{
+ struct nlmsghdr *nlh = msg->nm_nlh;
+ struct timeval tv;
+
+ if (!nlh) {
+ int errsv = errno;
+ fprintf(stderr, "Netlink message header is NULL!\n");
+ return -errsv;
+ }
+
+ /* Complete the nl_msg header */
+ if (gettimeofday(&tv, NULL))
+ nlh->nlmsg_seq = 1;
+ else
+ nlh->nlmsg_seq = (int) tv.tv_sec;
+ nlh->nlmsg_pid = sk->s_local.nl_pid;
+ nlh->nlmsg_flags |= NLM_F_REQUEST | NLM_F_ACK;
+
+ return nl_send(sk, msg);
+}
+
+/* Receives a netlink message, allocates a buffer in *buf and stores
+ * the message content. The peer's netlink address is stored in
+ * *nla. The caller is responsible for freeing the buffer allocated in
+ * *buf if a positive value is returned. Interrupted system calls are
+ * handled by repeating the read. The input buffer size is determined
+ * by peeking before the actual read is done */
+int nl_recv(struct nl_sock *sk, struct sockaddr_nl *nla, \
+ unsigned char **buf, struct ucred **creds)
+{
+ int rc = -1;
+ int sk_flags;
+ int RECV_BUF_SIZE;
+ int errsv;
+ struct iovec recvmsg_iov;
+ struct msghdr msg;
+
+ /* Allocate buffer */
+ RECV_BUF_SIZE = getpagesize();
+ *buf = (unsigned char *) malloc(RECV_BUF_SIZE);
+ if (!buf) {
+ rc = -ENOMEM;
+ goto fail;
+ }
+
+ /* Prepare to receive message */
+ recvmsg_iov.iov_base = *buf;
+ recvmsg_iov.iov_len = RECV_BUF_SIZE;
+
+ msg.msg_name = (void *) &sk->s_peer;
+ msg.msg_namelen = sizeof(sk->s_peer);
+ msg.msg_iov = &recvmsg_iov;
+ msg.msg_iovlen = 1;
+ msg.msg_control = NULL;
+ msg.msg_controllen = 0;
+ msg.msg_flags = 0;
+
+ /* Make non blocking and then restore previous setting */
+ sk_flags = fcntl(sk->s_fd, F_GETFL, 0);
+ fcntl(sk->s_fd, F_SETFL, O_NONBLOCK);
+ rc = recvmsg(sk->s_fd, &msg, 0);
+ errsv = errno;
+ fcntl(sk->s_fd, F_SETFL, sk_flags);
+
+ if (rc < 0)
+ rc = -errsv;
+
+fail:
+ return rc;
+}
+
+/* Receive a set of messages from a netlink socket */
+/* NOTE: Does not currently support callback replacements!!! */
+int nl_recvmsgs(struct nl_sock *sk, struct nl_cb *cb)
+{
+ struct sockaddr_nl nla;
+ struct ucred *creds;
+
+ int rc, cb_rc = NL_OK, done = 0;
+
+ do {
+
+ unsigned char *buf;
+ int i, rem, flags;
+ struct nlmsghdr *nlh;
+ struct nlmsgerr *nlme;
+ struct nl_msg *msg;
+
+ done = 0;
+ rc = nl_recv(sk, &nla, &buf, &creds);
+ if (rc < 0)
+ break;
+
+ nlmsg_for_each_msg(nlh, (struct nlmsghdr *) buf, rc, rem) {
+
+ if (rc <= 0 || cb_rc == NL_STOP)
+ break;
+
+ /* Check for callbacks */
+
+ msg = (struct nl_msg *)malloc(sizeof(struct nl_msg));
+ memset(msg, 0, sizeof(*msg));
+ msg->nm_nlh = nlh;
+
+ /* Check netlink message type */
+
+ switch (msg->nm_nlh->nlmsg_type) {
+ case NLMSG_ERROR: /* Used for ACK too */
+ /* Certainly we should be doing some
+ * checking here to make sure this
+ * message is intended for us */
+ nlme = nlmsg_data(msg->nm_nlh);
+ if (nlme->error == 0)
+ msg->nm_nlh->nlmsg_flags |= NLM_F_ACK;
+
+ rc = nlme->error;
+ cb_rc = cb->cb_err(&nla, nlme, cb->cb_err_arg);
+ nlme = NULL;
+ break;
+
+ case NLMSG_DONE:
+ done = 1;
+
+ case NLMSG_OVERRUN:
+ case NLMSG_NOOP:
+ default:
+ break;
+ };
+
+ for (i = 0; i <= NL_CB_TYPE_MAX; i++) {
+
+ if (cb->cb_set[i]) {
+ switch (i) {
+ case NL_CB_VALID:
+ if (rc > 0)
+ cb_rc = cb->cb_set[i](msg, cb->cb_args[i]);
+ break;
+
+ case NL_CB_FINISH:
+ if ((msg->nm_nlh->nlmsg_flags & NLM_F_MULTI) &&
+ (msg->nm_nlh->nlmsg_type & NLMSG_DONE))
+ cb_rc = cb->cb_set[i](msg, cb->cb_args[i]);
+
+ break;
+
+ case NL_CB_ACK:
+ if (msg->nm_nlh->nlmsg_flags & NLM_F_ACK)
+ cb_rc = cb->cb_set[i](msg, cb->cb_args[i]);
+
+ break;
+ default:
+ break;
+ }
+ }
+ }
+
+ free(msg);
+ if (done)
+ break;
+ }
+
+ free(buf);
+ buf = NULL;
+
+ if (done)
+ break;
+ } while (rc > 0 && cb_rc != NL_STOP);
+
+success:
+fail:
+ return rc;
+}
+
+/* Send raw data over netlink socket */
+int nl_send(struct nl_sock *sk, struct nl_msg *msg)
+{
+ struct nlmsghdr *nlh = nlmsg_hdr(msg);
+ struct iovec msg_iov;
+
+ /* Create IO vector with Netlink message */
+ msg_iov.iov_base = nlh;
+ msg_iov.iov_len = nlh->nlmsg_len;
+
+ return nl_send_iovec(sk, msg, &msg_iov, 1);
+}
+
+/* Send netlink message */
+int nl_send_iovec(struct nl_sock *sk, struct nl_msg *msg,
+ struct iovec *iov, unsigned iovlen)
+{
+ int rc;
+
+ /* Socket message */
+ struct msghdr mh = {
+ .msg_name = (void *) &sk->s_peer,
+ .msg_namelen = sizeof(sk->s_peer),
+ .msg_iov = iov,
+ .msg_iovlen = iovlen,
+ .msg_control = NULL,
+ .msg_controllen = 0,
+ .msg_flags = 0
+ };
+
+ /* Send message and verify sent */
+ rc = nl_sendmsg(sk, (struct nl_msg *) &mh, 0);
+ if (rc < 0)
+ fprintf(stderr, "Error sending netlink message: %d\n", errno);
+ return rc;
+
+}
+
+/* Send netlink message with control over sendmsg() message header */
+int nl_sendmsg(struct nl_sock *sk, struct nl_msg *msg, struct msghdr *hdr)
+{
+ return sendmsg(sk->s_fd, (struct msghdr *) msg, (int) hdr);
+}
+
+/* Create and connect netlink socket */
+int nl_connect(struct nl_sock *sk, int protocol)
+{
+ struct sockaddr addr;
+ socklen_t addrlen;
+ int rc;
+
+ /* Create RX socket */
+ sk->s_fd = socket(PF_NETLINK, SOCK_RAW, protocol);
+ if (sk->s_fd < 0)
+ return -errno;
+
+ /* Set size of RX and TX buffers */
+ if (nl_socket_set_buffer_size(sk, NL_BUFFER_SZ, NL_BUFFER_SZ) < 0)
+ return -errno;
+
+ /* Bind RX socket */
+ rc = bind(sk->s_fd, (struct sockaddr *)&sk->s_local, \
+ sizeof(sk->s_local));
+ if (rc < 0)
+ return -errno;
+ addrlen = sizeof(addr);
+ getsockname(sk->s_fd, &addr, &addrlen);
+
+ return 0;
+
+}