def nl_send_simple(sk, type_, flags, buf=None, size=0):
"""Construct and transmit a Netlink message.
https://github.com/thom311/libnl/blob/libnl3_2_25/lib/nl.c#L549
Allocates a new Netlink message based on `type_` and `flags`. If `buf` points to payload of length `size` that
payload will be appended to the message.
Sends out the message using `nl_send_auto()`.
Positional arguments:
sk -- Netlink socket (nl_sock class instance).
type_ -- Netlink message type (integer).
flags -- Netlink message flags (integer).
Keyword arguments:
buf -- payload data.
size -- size of `data` (integer).
Returns:
Number of characters sent on success or a negative error code.
"""
msg = nlmsg_alloc_simple(type_, flags)
if buf is not None and size:
err = nlmsg_append(msg, buf, size, NLMSG_ALIGNTO)
if err < 0:
return err
return nl_send_auto(sk, msg)
def nl_send_simple(sk, type_, flags, buf=None, size=0):
"""Construct and transmit a Netlink message.
https://github.com/thom311/libnl/blob/libnl3_2_25/lib/nl.c#L549
Allocates a new Netlink message based on `type_` and `flags`. If `buf` points to payload of length `size` that
payload will be appended to the message.
Sends out the message using `nl_send_auto()`.
Positional arguments:
sk -- Netlink socket (nl_sock class instance).
type_ -- Netlink message type (integer).
flags -- Netlink message flags (integer).
Keyword arguments:
buf -- payload data.
size -- size of `data` (integer).
Returns:
Number of characters sent on success or a negative error code.
"""
msg = nlmsg_alloc_simple(type_, flags)
if buf is not None and size:
err = nlmsg_append(msg, buf, size, NLMSG_ALIGNTO)
if err < 0:
return err
return nl_send_auto(sk, msg)
def test_s_proto():
"""Test socket protocol."""
sk = nl_socket_alloc()
nl_connect(sk, NETLINK_ROUTE)
msg = nlmsg_alloc_simple(0, 0)
assert -1 == msg.nm_protocol
nl_complete_msg(sk, msg)
assert NETLINK_ROUTE == msg.nm_protocol
nl_socket_free(sk)
def test_nm_protocol():
"""Test protocol."""
sk = nl_socket_alloc()
msg = nlmsg_alloc_simple(0, 0)
assert -1 == msg.nm_protocol
msg.nm_protocol = 10
nl_complete_msg(sk, msg)
assert 10 == msg.nm_protocol
nl_socket_free(sk)
def test_nlmsg_pid():
"""Test pid."""
sk = nl_socket_alloc()
msg = nlmsg_alloc_simple(0, 0)
assert 0 == msg.nm_nlh.nlmsg_pid
msg.nm_nlh.nlmsg_pid = 10
nl_complete_msg(sk, msg)
assert 10 == msg.nm_nlh.nlmsg_pid
nl_socket_free(sk)
def test_dissect(monkeypatch):
r"""Diff of C code (from test_bare()) to test against.
--- test_bare.c 2015-02-08 12:43:15.543135855 -0800
+++ test_dissect.c 2015-02-08 13:25:31.375715668 -0800
@@ -16,8 +16,22 @@
sk->s_local.nl_pid = 0;
sk->s_seq_next = 0;
- int ret = nl_send_simple(sk, RTM_GETLINK, 0, NULL, 0);
+ struct rtgenmsg rt_hdr = { .rtgen_family = AF_PACKET, };
+ struct nl_msg *msg = nlmsg_alloc_simple(RTM_GETLINK, NLM_F_REQUEST | NLM_F_DUMP);
+ nlmsg_append(msg, &rt_hdr, sizeof(rt_hdr), NLMSG_ALIGNTO);
+ nl_complete_msg(sk, msg);
+ struct nlmsghdr *nlh = nlmsg_hdr(msg);
+ printf("%d == nlh->nlmsg_len\n", nlh->nlmsg_len);
+ printf("%d == nlh->nlmsg_type\n", nlh->nlmsg_type);
+ printf("%d == nlh->nlmsg_flags\n", nlh->nlmsg_flags);
+ printf("%d == nlh->nlmsg_seq\n", nlh->nlmsg_seq);
+ printf("%d == nlh->nlmsg_pid\n", nlh->nlmsg_pid);
+
+ struct iovec iov = { .iov_base = nlh, .iov_len = nlh->nlmsg_len };
+ struct msghdr hdr = { .msg_iov = &iov, .msg_iovlen = 1, };
+
+ int ret = nl_sendmsg(sk, msg, &hdr);
printf("Bytes: %d\n", ret);
return 0;
}
"""
monkeypatch.setattr(libnl.socket_, 'generate_local_port', lambda: 0)
sk = nl_socket_alloc()
nl_connect(sk, NETLINK_ROUTE)
sk.socket_instance.close()
sk.s_local.nl_pid = 0
sk.s_seq_next = 0
rt_hdr = rtgenmsg(rtgen_family=socket.AF_PACKET)
msg = nlmsg_alloc_simple(RTM_GETLINK, NLM_F_REQUEST | NLM_F_DUMP)
nlmsg_append(msg, rt_hdr, rt_hdr.SIZEOF, NLMSG_ALIGNTO)
nl_complete_msg(sk, msg)
nlh = nlmsg_hdr(msg)
assert 20 == nlh.nlmsg_len
assert 18 == nlh.nlmsg_type
assert 773 == nlh.nlmsg_flags
assert 0 == nlh.nlmsg_seq
assert 0 == nlh.nlmsg_pid
assert b'FAAAABIABQMAAAAAAAAAABEAAAA=' == base64.b64encode(
buffer(nlh.bytearray[:nlh.nlmsg_len]))
nl_socket_free(sk)
def test_dissect(monkeypatch):
r"""Diff of C code (from test_bare()) to test against.
--- test_bare.c 2015-02-08 12:43:15.543135855 -0800
+++ test_dissect.c 2015-02-08 13:25:31.375715668 -0800
@@ -16,8 +16,22 @@
sk->s_local.nl_pid = 0;
sk->s_seq_next = 0;
- int ret = nl_send_simple(sk, RTM_GETLINK, 0, NULL, 0);
+ struct rtgenmsg rt_hdr = { .rtgen_family = AF_PACKET, };
+ struct nl_msg *msg = nlmsg_alloc_simple(RTM_GETLINK, NLM_F_REQUEST | NLM_F_DUMP);
+ nlmsg_append(msg, &rt_hdr, sizeof(rt_hdr), NLMSG_ALIGNTO);
+ nl_complete_msg(sk, msg);
+ struct nlmsghdr *nlh = nlmsg_hdr(msg);
+ printf("%d == nlh->nlmsg_len\n", nlh->nlmsg_len);
+ printf("%d == nlh->nlmsg_type\n", nlh->nlmsg_type);
+ printf("%d == nlh->nlmsg_flags\n", nlh->nlmsg_flags);
+ printf("%d == nlh->nlmsg_seq\n", nlh->nlmsg_seq);
+ printf("%d == nlh->nlmsg_pid\n", nlh->nlmsg_pid);
+
+ struct iovec iov = { .iov_base = nlh, .iov_len = nlh->nlmsg_len };
+ struct msghdr hdr = { .msg_iov = &iov, .msg_iovlen = 1, };
+
+ int ret = nl_sendmsg(sk, msg, &hdr);
printf("Bytes: %d\n", ret);
return 0;
}
"""
monkeypatch.setattr(libnl.socket_, 'generate_local_port', lambda: 0)
sk = nl_socket_alloc()
nl_connect(sk, NETLINK_ROUTE)
sk.socket_instance.close()
sk.s_local.nl_pid = 0
sk.s_seq_next = 0
rt_hdr = rtgenmsg(rtgen_family=socket.AF_PACKET)
msg = nlmsg_alloc_simple(RTM_GETLINK, NLM_F_REQUEST | NLM_F_DUMP)
nlmsg_append(msg, rt_hdr, rt_hdr.SIZEOF, NLMSG_ALIGNTO)
nl_complete_msg(sk, msg)
nlh = nlmsg_hdr(msg)
assert 20 == nlh.nlmsg_len
assert 18 == nlh.nlmsg_type
assert 773 == nlh.nlmsg_flags
assert 0 == nlh.nlmsg_seq
assert 0 == nlh.nlmsg_pid
assert b'FAAAABIABQMAAAAAAAAAABEAAAA=' == base64.b64encode(buffer(nlh.bytearray[:nlh.nlmsg_len]))
nl_socket_free(sk)
def test_error_nle_bad_sock():
"""Test for NLE_BAD_SOCK."""
sk = nl_socket_alloc()
msg = nlmsg_alloc_simple(0, 0)
nl_connect(sk, NETLINK_ROUTE)
sk.socket_instance.close()
nl_complete_msg(sk, msg)
message = 'Hello World!\n'
iov = bytes(message.encode('ascii'))
hdr = msghdr(msg_iov=iov)
assert -3 == nl_sendmsg(sk, msg, hdr)
def test_default(tcp_server):
r"""C code to test against.
// gcc a.c $(pkg-config --cflags --libs libnl-genl-3.0)
// (nc -l 2000 &); sleep 0.1; ./a.out
#include <netlink/msg.h>
struct nl_sock {
struct sockaddr_nl s_local; struct sockaddr_nl s_peer; int s_fd; int s_proto; unsigned int s_seq_next;
unsigned int s_seq_expect; int s_flags; struct nl_cb *s_cb; size_t s_bufsize;
};
int main() {
struct sockaddr_in sin = { .sin_port = htons(2000), .sin_family = AF_INET, };
sin.sin_addr.s_addr = inet_addr("127.0.0.1");
int fd = socket(AF_INET, SOCK_STREAM, 0);
connect(fd, (struct sockaddr *) &sin, sizeof(sin));
struct nl_sock *sk = nl_socket_alloc();
struct nl_msg *msg = nlmsg_alloc_simple(0, 0);
nl_connect(sk, NETLINK_ROUTE);
sk->s_fd = fd;
sk->s_local.nl_pid = 0;
nl_complete_msg(sk, msg);
char message[] = "Hello World!\n";
struct iovec iov = { .iov_base = message, .iov_len = sizeof(message), };
struct msghdr hdr = { .msg_iov = &iov, .msg_iovlen = 1, };
int ret = nl_sendmsg(sk, msg, &hdr);
printf("Bytes: %d\n", ret); // 14
return 0;
}
// Expected bash output:
// Hello World!
// Bytes: 14
"""
sk = nl_socket_alloc()
msg = nlmsg_alloc_simple(0, 0)
nl_connect(sk, NETLINK_ROUTE)
sk.socket_instance.close()
sk.socket_instance = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sk.socket_instance.connect(tcp_server.server.server_address)
sk.s_local.nl_pid = 0
nl_complete_msg(sk, msg)
message = 'Hello World!\n\0'
iov = bytes(message.encode('ascii'))
hdr = msghdr(msg_iov=iov)
assert 14 == nl_sendmsg(sk, msg, hdr)
assert [iov] == tcp_server.data
nl_socket_free(sk)
def test_defaults(log):
r"""C code to test against.
// gcc a.c $(pkg-config --cflags --libs libnl-genl-3.0) && NLDBG=4 ./a.out
#include <netlink/msg.h>
struct ucred { __u32 pid; __u32 uid; __u32 gid; };
struct nl_msg {
int nm_protocol; int nm_flags; struct sockaddr_nl nm_src; struct sockaddr_nl nm_dst; struct ucred nm_creds;
struct nlmsghdr *nm_nlh; size_t nm_size; int nm_refcnt;
};
struct nl_sock {
struct sockaddr_nl s_local; struct sockaddr_nl s_peer; int s_fd; int s_proto; unsigned int s_seq_next;
unsigned int s_seq_expect; int s_flags; struct nl_cb *s_cb; size_t s_bufsize;
};
void print(struct nl_msg *msg) {
printf("%d == msg.nm_protocol\n", msg->nm_protocol);
printf("%d == msg.nm_flags\n", msg->nm_flags);
printf("%d == msg.nm_src.nl_family\n", msg->nm_src.nl_family);
printf("%d == msg.nm_src.nl_pid\n", msg->nm_src.nl_pid);
printf("%d == msg.nm_src.nl_groups\n", msg->nm_src.nl_groups);
printf("%d == msg.nm_dst.nl_family\n", msg->nm_dst.nl_family);
printf("%d == msg.nm_dst.nl_pid\n", msg->nm_dst.nl_pid);
printf("%d == msg.nm_dst.nl_groups\n", msg->nm_dst.nl_groups);
printf("%d == msg.nm_nlh.nlmsg_type\n", msg->nm_nlh->nlmsg_type);
printf("%d == msg.nm_nlh.nlmsg_flags\n", msg->nm_nlh->nlmsg_flags);
printf("%d == msg.nm_nlh.nlmsg_pid\n", msg->nm_nlh->nlmsg_pid);
}
int main() {
printf("Begin main()\n");
struct nl_sock *sk = nl_socket_alloc();
printf("Allocated socket.\n");
struct nl_msg *msg = nlmsg_alloc_simple(0, 0);
printf("Allocated message.\n");
printf("%d == nl_socket_get_local_port(sk)\n", nl_socket_get_local_port(sk));
printf("%d == sk.s_proto\n", sk->s_proto);
printf("\n");
print(msg);
printf("\n");
nl_complete_msg(sk, msg);
print(msg);
return 0;
}
// Expected output (trimmed):
// nl_cache_mngt_register: Registered cache operations genl/family
// Begin main()
// Allocated socket.
// __nlmsg_alloc: msg 0x1e9c0b8: Allocated new message, maxlen=4096
// nlmsg_alloc_simple: msg 0x1e9c0b8: Allocated new simple message
// Allocated message.
// 10083 == nl_socket_get_local_port(sk)
// 0 == sk.s_proto
//
// -1 == msg.nm_protocol
// 0 == msg.nm_flags
// 0 == msg.nm_src.nl_family
// 0 == msg.nm_src.nl_pid
// 0 == msg.nm_src.nl_groups
// 0 == msg.nm_dst.nl_family
// 0 == msg.nm_dst.nl_pid
// 0 == msg.nm_dst.nl_groups
// 0 == msg.nm_nlh.nlmsg_type
// 0 == msg.nm_nlh.nlmsg_flags
// 0 == msg.nm_nlh.nlmsg_pid
//
// 0 == msg.nm_protocol
// 0 == msg.nm_flags
// 0 == msg.nm_src.nl_family
// 0 == msg.nm_src.nl_pid
// 0 == msg.nm_src.nl_groups
// 0 == msg.nm_dst.nl_family
// 0 == msg.nm_dst.nl_pid
// 0 == msg.nm_dst.nl_groups
// 0 == msg.nm_nlh.nlmsg_type
// 5 == msg.nm_nlh.nlmsg_flags
// 10083 == msg.nm_nlh.nlmsg_pid
// nl_cache_mngt_unregister: Unregistered cache operations genl/family
"""
del log[:]
sk = nl_socket_alloc()
msg = nlmsg_alloc_simple(0, 0)
assert re.match('nlmsg_alloc: msg 0x[a-f0-9]+: Allocated new message', log.pop(0))
assert re.match('nlmsg_alloc_simple: msg 0x[a-f0-9]+: Allocated new simple message', log.pop(0))
local_port = int(nl_socket_get_local_port(sk))
proto = int(sk.s_proto)
assert 0 < local_port
assert 0 == proto
assert -1 == msg.nm_protocol
assert 0 == msg.nm_flags
assert 0 == msg.nm_src.nl_family
assert 0 == msg.nm_src.nl_pid
assert 0 == msg.nm_src.nl_groups
assert 0 == msg.nm_dst.nl_family
assert 0 == msg.nm_dst.nl_pid
assert 0 == msg.nm_dst.nl_groups
assert 0 == msg.nm_nlh.nlmsg_type
assert 0 == msg.nm_nlh.nlmsg_flags
assert 0 == msg.nm_nlh.nlmsg_pid
nl_complete_msg(sk, msg)
assert proto == msg.nm_protocol
assert 0 == msg.nm_flags
assert 0 == msg.nm_src.nl_family
assert 0 == msg.nm_src.nl_pid
assert 0 == msg.nm_src.nl_groups
assert 0 == msg.nm_dst.nl_family
assert 0 == msg.nm_dst.nl_pid
assert 0 == msg.nm_dst.nl_groups
assert 0 == msg.nm_nlh.nlmsg_type
assert 5 == msg.nm_nlh.nlmsg_flags
assert local_port == msg.nm_nlh.nlmsg_pid
assert not log
nl_socket_free(sk)