/**
* Send a message verdict including the payload
* @arg nlh netlink messsage header
* @arg msg queue msg
* @arg payload_data packet payload data
* @arg payload_len payload length
* @return 0 on OK or error code
*/
int nfnl_queue_msg_send_verdict_payload(struct nl_sock *nlh,
const struct nfnl_queue_msg *msg,
const void *payload_data, unsigned payload_len)
{
struct nl_msg *nlmsg;
int err;
struct iovec iov[3];
struct nlattr nla;
nlmsg = nfnl_queue_msg_build_verdict(msg);
if (nlmsg == NULL)
return -NLE_NOMEM;
memset(iov, 0, sizeof(iov));
iov[0].iov_base = (void *) nlmsg_hdr(nlmsg);
iov[0].iov_len = nlmsg_hdr(nlmsg)->nlmsg_len;
nla.nla_type = NFQA_PAYLOAD;
nla.nla_len = payload_len + sizeof(nla);
nlmsg_hdr(nlmsg)->nlmsg_len += nla.nla_len;
iov[1].iov_base = (void *) &nla;
iov[1].iov_len = sizeof(nla);
iov[2].iov_base = (void *) payload_data;
iov[2].iov_len = NLA_ALIGN(payload_len);
nl_complete_msg(nlh, nlmsg);
err = nl_send_iovec(nlh, nlmsg, iov, 3);
nlmsg_free(nlmsg);
if (err < 0)
return err;
return wait_for_ack(nlh);
}
/**
* Send netlink message.
* @arg sk Netlink socket.
* @arg msg Netlink message to be sent.
* @arg iov iovec to be sent.
* @arg iovlen number of struct iovec to be sent.
* @see nl_sendmsg()
* @return Number of characters sent on success or a negative error code.
*/
int nl_send_iovec(struct nl_sock *sk, struct nl_msg *msg, struct iovec *iov, unsigned iovlen)
{
struct sockaddr_nl *dst;
struct ucred *creds;
struct msghdr hdr = {
.msg_name = (void *) &sk->s_peer,
.msg_namelen = sizeof(struct sockaddr_nl),
.msg_iov = iov,
.msg_iovlen = iovlen,
};
/* Overwrite destination if specified in the message itself, defaults
* to the peer address of the socket.
*/
dst = nlmsg_get_dst(msg);
if (dst->nl_family == AF_NETLINK)
hdr.msg_name = dst;
/* Add credentials if present. */
creds = nlmsg_get_creds(msg);
if (creds != NULL) {
char buf[CMSG_SPACE(sizeof(struct ucred))];
struct cmsghdr *cmsg;
hdr.msg_control = buf;
hdr.msg_controllen = sizeof(buf);
cmsg = CMSG_FIRSTHDR(&hdr);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_CREDENTIALS;
cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
memcpy(CMSG_DATA(cmsg), creds, sizeof(struct ucred));
}
return nl_sendmsg(sk, msg, &hdr);
}
/**
* Send netlink message.
* @arg sk Netlink socket.
* @arg msg Netlink message to be sent.
* @see nl_sendmsg()
* @return Number of characters sent on success or a negative error code.
*/
int nl_send(struct nl_sock *sk, struct nl_msg *msg)
{
struct iovec iov = {
.iov_base = (void *) nlmsg_hdr(msg),
.iov_len = nlmsg_hdr(msg)->nlmsg_len,
};
return nl_send_iovec(sk, msg, &iov, 1);
}
void nl_complete_msg(struct nl_sock *sk, struct nl_msg *msg)
{
struct nlmsghdr *nlh;
nlh = nlmsg_hdr(msg);
if (nlh->nlmsg_pid == 0)
nlh->nlmsg_pid = sk->s_local.nl_pid;
if (nlh->nlmsg_seq == 0)
nlh->nlmsg_seq = sk->s_seq_next++;
if (msg->nm_protocol == -1)
msg->nm_protocol = sk->s_proto;
nlh->nlmsg_flags |= NLM_F_REQUEST;
if (!(sk->s_flags & NL_NO_AUTO_ACK))
nlh->nlmsg_flags |= NLM_F_ACK;
}
void nl_auto_complete(struct nl_sock *sk, struct nl_msg *msg)
{
nl_complete_msg(sk, msg);
}
/**
* Automatically complete and send a netlink message
* @arg sk Netlink socket.
* @arg msg Netlink message to be sent.
*
* This function takes a netlink message and passes it on to
* nl_auto_complete() for completion.
*
* Checks the netlink message \c nlh for completness and extends it
* as required before sending it out. Checked fields include pid,
* sequence nr, and flags.
*
* @see nl_send()
* @return Number of characters sent or a negative error code.
*/
int nl_send_auto(struct nl_sock *sk, struct nl_msg *msg)
{
struct nl_cb *cb = sk->s_cb;
nl_complete_msg(sk, msg);
if (cb->cb_send_ow)
return cb->cb_send_ow(sk, msg);
else
return nl_send(sk, msg);
}
int nl_send_auto_complete(struct nl_sock *sk, struct nl_msg *msg)
{
return nl_send_auto(sk, msg);
}
/**
* Send netlink message and wait for response (sync request-response)
* @arg sk Netlink socket
* @arg msg Netlink message to be sent
*
* This function takes a netlink message and sends it using nl_send_auto().
* It will then wait for the response (ACK or error message) to be
* received. Threfore this function will block until the operation has
* been completed.
*
* @note Disabling auto-ack (nl_socket_disable_auto_ack()) will cause
* this function to return immediately after sending. In this case,
* it is the responsibility of the caller to handle any eventual
* error messages returned.
*
* @see nl_send_auto().
*
* @return 0 on success or a negative error code.
*/
int nl_send_sync(struct nl_sock *sk, struct nl_msg *msg)
{
int err;
err = nl_send_auto(sk, msg);
nlmsg_free(msg);
if (err < 0)
return err;
return wait_for_ack(sk);
}
/**
* Transmit Netlink message (taking IO vector)
* @arg sk Netlink socket (required)
* @arg msg Netlink message to be sent (required)
* @arg iov IO vector to be sent (required)
* @arg iovlen Number of struct iovec to be sent (required)
*
* This function is identical to nl_send() except that instead of taking a
* `struct nl_msg` object it takes an IO vector. Please see the description
* of `nl_send()`.
*
* @callback This function triggers the `NL_CB_MSG_OUT` callback.
*
* @see nl_send()
*
* @return Number of bytes sent on success or a negative error code.
*
* @lowlevel
*/
int nl_send_iovec(struct nl_sock *sk, struct nl_msg *msg, struct iovec *iov, unsigned iovlen)
{
struct sockaddr_nl *dst;
struct ucred *creds;
struct msghdr hdr = {
.msg_name = (void *) &sk->s_peer,
.msg_namelen = sizeof(struct sockaddr_nl),
.msg_iov = iov,
.msg_iovlen = iovlen,
};
/* Overwrite destination if specified in the message itself, defaults
* to the peer address of the socket.
*/
dst = nlmsg_get_dst(msg);
if (dst->nl_family == AF_NETLINK)
hdr.msg_name = dst;
/* Add credentials if present. */
creds = nlmsg_get_creds(msg);
if (creds != NULL) {
char buf[CMSG_SPACE(sizeof(struct ucred))];
struct cmsghdr *cmsg;
hdr.msg_control = buf;
hdr.msg_controllen = sizeof(buf);
cmsg = CMSG_FIRSTHDR(&hdr);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_CREDENTIALS;
cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
memcpy(CMSG_DATA(cmsg), creds, sizeof(struct ucred));
}
return nl_sendmsg(sk, msg, &hdr);
}
/**
* Transmit Netlink message
* @arg sk Netlink socket (required)
* @arg msg Netlink message (required)
*
* Transmits the Netlink message `msg` over the Netlink socket using the
* `sendmsg()` system call. This function is based on `nl_send_iovec()` but
* takes care of initializing a `struct iovec` based on the `msg` object.
*
* The message is addressed to the peer as specified in the socket by either
* the nl_socket_set_peer_port() or nl_socket_set_peer_groups() function.
* The peer address can be overwritten by specifying an address in the `msg`
* object using nlmsg_set_dst().
*
* If present in the `msg`, credentials set by the nlmsg_set_creds() function
* are added to the control buffer of the message.
*
* @par Overwriting Capability:
* Calls to this function can be overwritten by providing an alternative using
* the nl_cb_overwrite_send() function.
*
* @callback This function triggers the `NL_CB_MSG_OUT` callback.
*
* @attention
* Unlike `nl_send_auto()`, this function does *not* finalize the message in
* terms of automatically adding needed flags or filling out port numbers.
*
* @see nl_send_auto()
* @see nl_send_iovec()
* @see nl_socket_set_peer_port()
* @see nl_socket_set_peer_groups()
* @see nlmsg_set_dst()
* @see nlmsg_set_creds()
* @see nl_cb_overwrite_send()
*
* @return Number of bytes sent on success or a negative error code.
*/
int nl_send(struct nl_sock *sk, struct nl_msg *msg)
{
struct nl_cb *cb = sk->s_cb;
if (cb->cb_send_ow)
return cb->cb_send_ow(sk, msg);
else {
struct iovec iov = {
.iov_base = (void *) nlmsg_hdr(msg),
.iov_len = nlmsg_hdr(msg)->nlmsg_len,
};
return nl_send_iovec(sk, msg, &iov, 1);
}
}
/**
* Finalize Netlink message
* @arg sk Netlink socket (required)
* @arg msg Netlink message (required)
*
* This function finalizes a Netlink message by completing the message with
* desirable flags and values depending on the socket configuration.
*
* - If not yet filled out, the source address of the message (`nlmsg_pid`)
* will be set to the local port number of the socket.
* - If not yet specified, the next available sequence number is assigned
* to the message (`nlmsg_seq`).
* - If not yet specified, the protocol field of the message will be set to
* the protocol field of the socket.
* - The `NLM_F_REQUEST` Netlink message flag will be set.
* - The `NLM_F_ACK` flag will be set if Auto-ACK mode is enabled on the
* socket.
*/
void nl_complete_msg(struct nl_sock *sk, struct nl_msg *msg)
{
struct nlmsghdr *nlh;
nlh = nlmsg_hdr(msg);
if (nlh->nlmsg_pid == NL_AUTO_PORT)
nlh->nlmsg_pid = nl_socket_get_local_port(sk);
if (nlh->nlmsg_seq == NL_AUTO_SEQ)
nlh->nlmsg_seq = sk->s_seq_next++;
if (msg->nm_protocol == -1)
msg->nm_protocol = sk->s_proto;
nlh->nlmsg_flags |= NLM_F_REQUEST;
if (!(sk->s_flags & NL_NO_AUTO_ACK))
nlh->nlmsg_flags |= NLM_F_ACK;
}
/**
* Finalize and transmit Netlink message
* @arg sk Netlink socket (required)
* @arg msg Netlink message (required)
*
* Finalizes the message by passing it to `nl_complete_msg()` and transmits it
* by passing it to `nl_send()`.
*
* @callback This function triggers the `NL_CB_MSG_OUT` callback.
*
* @see nl_complete_msg()
* @see nl_send()
*
* @return Number of bytes sent or a negative error code.
*/
int nl_send_auto(struct nl_sock *sk, struct nl_msg *msg)
{
nl_complete_msg(sk, msg);
return nl_send(sk, msg);
}
/**
* Finalize and transmit Netlink message and wait for ACK or error message
* @arg sk Netlink socket (required)
* @arg msg Netlink message (required)
*
* Passes the `msg` to `nl_send_auto()` to finalize and transmit it. Frees the
* message and waits (sleeps) for the ACK or error message to be received.
*
* @attention
* Disabling Auto-ACK (nl_socket_disable_auto_ack()) will cause this function
* to return immediately after transmitting the message. However, the peer may
* still be returning an error message in response to the request. It is the
* responsibility of the caller to handle such messages.
*
* @callback This function triggers the `NL_CB_MSG_OUT` callback.
*
* @attention
* This function frees the `msg` object after transmitting it by calling
* `nlmsg_free()`.
*
* @see nl_send_auto().
* @see nl_wait_for_ack()
*
* @return 0 on success or a negative error code.
*/
int nl_send_sync(struct nl_sock *sk, struct nl_msg *msg)
{
int err;
err = nl_send_auto(sk, msg);
nlmsg_free(msg);
if (err < 0)
return err;
return wait_for_ack(sk);
}
/**
* @deprecated Please use nl_complete_msg()
*/
void nl_auto_complete(struct nl_sock *sk, struct nl_msg *msg)
{
nl_complete_msg(sk, msg);
}
