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netlink: improve RTM_GETADDR handling.

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* Allow filtering by ifa_family & ifa_index.
* Add common RTM_<NEW|DEL|GET>ADDR parser
* Add tests verifying RTM_GETADDR filtering behaviour & output
* Factor out common netlink socket test methods into NetlinkTestTemplate
* Add NLMSG_DONE message handler

Reviewed By: pauamma
Differential Revision: https://reviews.freebsd.org/D37970
This commit is contained in:
Alexander V. Chernikov 2023-01-07 16:18:39 +00:00
parent 4ffe60e683
commit c1871a3372
7 changed files with 321 additions and 67 deletions
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17
share/man/man4/rtnetlink.4
View File

@ -403,14 +403,27 @@ Not supported
.Ss RTM_DELADDR
Not supported
.Ss RTM_GETADDR
Fetches interface addresses in the current VNET matching conditions.
Each address is reported as a
.Dv RTM_NEWADDR
message.
The following filters are recognised by the kernel:
.Pp
.Bd -literal -offset indent -compact
ifa_family required family or AF_UNSPEC
ifa_index matching interface index or 0
.Ed
.Ss TLVs
.Bl -tag -width indent
.It Dv IFA_ADDRESS
(binary) masked interface address or destination address for p2p interfaces.
.It Dv IFA_LOCAL
(binary) local interface address
(binary) local interface address.
Set for IPv4 and p2p addresses.
.It Dv IFA_LABEL
(string) interface name.
.It Dv IFA_BROADCAST
(binary) broacast interface address
(binary) broacast interface address.
.El
.Ss Groups
The following groups are defined:

87
sys/netlink/route/iface.c
View File

@ -672,6 +672,36 @@ rtnl_handle_newlink(struct nlmsghdr *hdr, struct nlpcb *nlp, struct nl_pstate *n
return (modify_link(hdr, &attrs, &bm, nlp, npt));
}
struct nl_parsed_ifa {
uint8_t ifa_family;
uint8_t ifa_prefixlen;
uint8_t ifa_scope;
uint32_t ifa_index;
uint32_t ifa_flags;
struct sockaddr *ifa_address;
struct sockaddr *ifa_local;
};
#define _IN(_field) offsetof(struct ifaddrmsg, _field)
#define _OUT(_field) offsetof(struct nl_parsed_ifa, _field)
static const struct nlfield_parser nlf_p_ifa[] = {
{ .off_in = _IN(ifa_family), .off_out = _OUT(ifa_family), .cb = nlf_get_u8 },
{ .off_in = _IN(ifa_prefixlen), .off_out = _OUT(ifa_prefixlen), .cb = nlf_get_u8 },
{ .off_in = _IN(ifa_scope), .off_out = _OUT(ifa_scope), .cb = nlf_get_u8 },
{ .off_in = _IN(ifa_flags), .off_out = _OUT(ifa_flags), .cb = nlf_get_u8_u32 },
{ .off_in = _IN(ifa_index), .off_out = _OUT(ifa_index), .cb = nlf_get_u32 },
};
static const struct nlattr_parser nla_p_ifa[] = {
{ .type = IFA_ADDRESS, .off = _OUT(ifa_address), .cb = nlattr_get_ip },
{ .type = IFA_LOCAL, .off = _OUT(ifa_local), .cb = nlattr_get_ip },
{ .type = IFA_FLAGS, .off = _OUT(ifa_flags), .cb = nlattr_get_uint32 },
};
#undef _IN
#undef _OUT
NL_DECLARE_PARSER(ifaddrmsg_parser, struct ifaddrmsg, nlf_p_ifa, nla_p_ifa);
/*
{ifa_family=AF_INET, ifa_prefixlen=8, ifa_flags=IFA_F_PERMANENT, ifa_scope=RT_SCOPE_HOST, ifa_index=if_nametoindex("lo")},
@ -826,15 +856,39 @@ dump_iface_addr(struct nl_writer *nw, struct ifnet *ifp, struct ifaddr *ifa,
}
static int
rtnl_handle_getaddr(struct nlmsghdr *hdr, struct nlpcb *nlp, struct nl_pstate *npt)
dump_iface_addrs(struct netlink_walkargs *wa, struct ifnet *ifp)
{
struct ifaddr *ifa;
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (wa->family != 0 && wa->family != ifa->ifa_addr->sa_family)
continue;
if (ifa->ifa_addr->sa_family == AF_LINK)
continue;
wa->count++;
if (!dump_iface_addr(wa->nw, ifp, ifa, &wa->hdr))
return (ENOMEM);
wa->dumped++;
}
return (0);
}
static int
rtnl_handle_getaddr(struct nlmsghdr *hdr, struct nlpcb *nlp, struct nl_pstate *npt)
{
struct ifnet *ifp;
int error = 0;
struct nl_parsed_ifa attrs = {};
error = nl_parse_nlmsg(hdr, &ifaddrmsg_parser, npt, &attrs);
if (error != 0)
return (error);
struct netlink_walkargs wa = {
.so = nlp,
.nw = npt->nw,
.family = attrs.ifa_family,
.hdr.nlmsg_pid = hdr->nlmsg_pid,
.hdr.nlmsg_seq = hdr->nlmsg_seq,
.hdr.nlmsg_flags = hdr->nlmsg_flags | NLM_F_MULTI,
@ -843,22 +897,19 @@ rtnl_handle_getaddr(struct nlmsghdr *hdr, struct nlpcb *nlp, struct nl_pstate *n
NL_LOG(LOG_DEBUG2, "Start dump");
CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (wa.family != 0 && wa.family != ifa->ifa_addr->sa_family)
continue;
if (ifa->ifa_addr->sa_family == AF_LINK)
continue;
wa.count++;
if (!dump_iface_addr(wa.nw, ifp, ifa, &wa.hdr)) {
error = ENOMEM;
break;
}
wa.dumped++;
}
if (error != 0)
break;
}
if (attrs.ifa_index != 0) {
ifp = ifnet_byindex(attrs.ifa_index);
if (ifp == NULL)
error = ENOENT;
else
error = dump_iface_addrs(&wa, ifp);
} else {
CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
error = dump_iface_addrs(&wa, ifp);
if (error != 0)
break;
}
}
NL_LOG(LOG_DEBUG2, "End dump, iterated %d dumped %d", wa.count, wa.dumped);
@ -991,7 +1042,7 @@ static const struct rtnl_cmd_handler cmd_handlers[] = {
},
};
static const struct nlhdr_parser *all_parsers[] = { &ifmsg_parser };
static const struct nlhdr_parser *all_parsers[] = { &ifmsg_parser, &ifaddrmsg_parser };
void
rtnl_iface_add_cloner(struct nl_cloner *cloner)

2
sys/netlink/route/ifaddrs.h
View File

@ -52,7 +52,7 @@ enum {
IFA_UNSPEC,
IFA_ADDRESS = 1, /* binary, prefix address (destination for p2p) */
IFA_LOCAL = 2, /* binary, interface address */
IFA_LABEL = 3, /* not supported */
IFA_LABEL = 3, /* string, interface name */
IFA_BROADCAST = 4, /* binary, broadcast ifa */
IFA_ANYCAST = 5, /* not supported */
IFA_CACHEINFO = 6, /* not supported */

102
tests/atf_python/sys/net/netlink.py
View File

@ -49,6 +49,12 @@ class Nlmsghdr(Structure):
]
class Nlmsgdone(Structure):
_fields_ = [
("error", c_int),
]
class Nlmsgerr(Structure):
_fields_ = [
("error", c_int),
@ -961,6 +967,8 @@ def prepare_attrs_map(attrs: List[AttrDescr]) -> Dict[str, Dict]:
),
]
nldone_attrs = []
nlerr_attrs = [
AttrDescr(NlErrattrType.NLMSGERR_ATTR_MSG, NlAttrStr),
AttrDescr(NlErrattrType.NLMSGERR_ATTR_OFFS, NlAttrU32),
@ -989,6 +997,7 @@ def prepare_attrs_map(attrs: List[AttrDescr]) -> Dict[str, Dict]:
rtnl_ifa_attrs = [
AttrDescr(IfattrType.IFA_ADDRESS, NlAttrIp),
AttrDescr(IfattrType.IFA_LOCAL, NlAttrIp),
AttrDescr(IfattrType.IFA_LABEL, NlAttrStr),
AttrDescr(IfattrType.IFA_BROADCAST, NlAttrIp),
AttrDescr(IfattrType.IFA_ANYCAST, NlAttrIp),
AttrDescr(IfattrType.IFA_FLAGS, NlAttrU32),
@ -1167,6 +1176,25 @@ def print_message(self):
nla.print_attr(" ")
class NetlinkDoneMessage(StdNetlinkMessage):
messages = [NlMsgType.NLMSG_DONE.value]
nl_attrs_map = prepare_attrs_map(nldone_attrs)
@property
def error_code(self):
return self.base_hdr.error
def parse_base_header(self, data):
if len(data) < sizeof(Nlmsgdone):
raise ValueError("length less than nlmsgdone header")
done_hdr = Nlmsgdone.from_buffer_copy(data)
sz = sizeof(Nlmsgdone)
return (done_hdr, sz)
def print_base_header(self, hdr, prepend=""):
print("{}error={}".format(prepend, hdr.error))
class NetlinkErrorMessage(StdNetlinkMessage):
messages = [NlMsgType.NLMSG_ERROR.value]
nl_attrs_map = prepare_attrs_map(nlerr_attrs)
@ -1340,6 +1368,7 @@ def build_msgmap(self):
NetlinkRtMessage,
NetlinkIflaMessage,
NetlinkIfaMessage,
NetlinkDoneMessage,
NetlinkErrorMessage,
]
xmap = {}
@ -1476,20 +1505,63 @@ def request_families(self):
self.write_data(msg_bytes)
def main():
helper = NlHelper()
if False:
nl = Nlsock(NlConst.NETLINK_GENERIC, helper)
nl.request_families()
else:
nl = Nlsock(NlConst.NETLINK_ROUTE, helper)
# nl.request_ifaddrs(socket.AF_INET)
# nl.request_raw()
nl.request_routes(0)
# nl.request_ifaces()
while True:
msg = nl.read_message()
class NetlinkMultipartIterator(object):
def __init__(self, obj, seq_number: int, msg_type):
self._obj = obj
self._seq = seq_number
self._msg_type = msg_type
def __iter__(self):
return self
def __next__(self):
msg = self._obj.read_message()
if self._seq != msg.nl_hdr.nlmsg_seq:
raise ValueError("bad sequence number")
if msg.is_type(NlMsgType.NLMSG_ERROR):
raise ValueError(
"error while handling multipart msg: {}".format(msg.error_code)
)
elif msg.is_type(NlMsgType.NLMSG_DONE):
if msg.error_code == 0:
raise StopIteration
raise ValueError(
"error listing some parts of the multipart msg: {}".format(
msg.error_code
)
)
elif not msg.is_type(self._msg_type):
raise ValueError("bad message type: {}".format(msg))
return msg
class NetlinkTestTemplate(object):
REQUIRED_MODULES = ["netlink"]
def setup_netlink(self, netlink_family: NlConst):
self.helper = NlHelper()
self.nlsock = Nlsock(netlink_family, self.helper)
def write_message(self, msg):
print("")
print("============= >> TX MESSAGE =============")
msg.print_message()
msg.print_as_bytes(msg._orig_data, "-- DATA --")
pass
self.nlsock.write_data(bytes(msg))
msg.print_as_bytes(bytes(msg), "-- DATA --")
def read_message(self):
msg = self.nlsock.read_message()
print("")
print("============= << RX MESSAGE =============")
msg.print_message()
return msg
def get_reply(self, tx_msg):
self.write_message(tx_msg)
while True:
rx_msg = self.read_message()
if tx_msg.nl_hdr.nlmsg_seq == rx_msg.nl_hdr.nlmsg_seq:
return rx_msg
def read_msg_list(self, seq, msg_type):
return list(NetlinkMultipartIterator(self, seq, msg_type))

1
tests/sys/netlink/Makefile
View File

@ -7,6 +7,7 @@ TESTSDIR= ${TESTSBASE}/sys/netlink
ATF_TESTS_C += test_snl
ATF_TESTS_PYTEST += test_rtnl_iface.py
ATF_TESTS_PYTEST += test_rtnl_ifaddr.py
CFLAGS+= -I${.CURDIR:H:H:H}

35
tests/sys/netlink/test_rtnl_iface.py
View File

@ -6,49 +6,24 @@
from atf_python.sys.net.netlink import IflinkInfo
from atf_python.sys.net.netlink import IfLinkInfoDataVlan
from atf_python.sys.net.netlink import NetlinkIflaMessage
from atf_python.sys.net.netlink import NetlinkTestTemplate
from atf_python.sys.net.netlink import NlAttrNested
from atf_python.sys.net.netlink import NlAttrStr
from atf_python.sys.net.netlink import NlAttrStrn
from atf_python.sys.net.netlink import NlAttrU16
from atf_python.sys.net.netlink import NlAttrU32
from atf_python.sys.net.netlink import NlConst
from atf_python.sys.net.netlink import NlHelper
from atf_python.sys.net.netlink import NlmBaseFlags
from atf_python.sys.net.netlink import NlmNewFlags
from atf_python.sys.net.netlink import NlMsgType
from atf_python.sys.net.netlink import NlRtMsgType
from atf_python.sys.net.netlink import Nlsock
from atf_python.sys.net.vnet import SingleVnetTestTemplate
class TestRtNlIface(SingleVnetTestTemplate):
REQUIRED_MODULES = ["netlink"]
class TestRtNlIface(SingleVnetTestTemplate, NetlinkTestTemplate):
def setup_method(self, method):
super().setup_method(method)
self.helper = NlHelper()
self.nlsock = Nlsock(NlConst.NETLINK_ROUTE, self.helper)
def write_message(self, msg):
print("")
print("============= >> TX MESSAGE =============")
msg.print_message()
self.nlsock.write_data(bytes(msg))
msg.print_as_bytes(bytes(msg), "-- DATA --")
def read_message(self):
msg = self.nlsock.read_message()
print("")
print("============= << RX MESSAGE =============")
msg.print_message()
return msg
def get_reply(self, tx_msg):
self.write_message(tx_msg)
while True:
rx_msg = self.read_message()
if tx_msg.nl_hdr.nlmsg_seq == rx_msg.nl_hdr.nlmsg_seq:
return rx_msg
self.setup_netlink(NlConst.NETLINK_ROUTE)
def get_interface_byname(self, ifname):
msg = NetlinkIflaMessage(self.helper, NlRtMsgType.RTM_GETLINK.value)
@ -236,13 +211,11 @@ def test_delete_iface(self):
# *
# * {len=76, type=RTM_NEWLINK, flags=NLM_F_REQUEST|NLM_F_ACK|NLM_F_EXCL|NLM_F_CREATE, seq=1662892737, pid=0},
# * {ifi_family=AF_UNSPEC, ifi_type=ARPHRD_NETROM, ifi_index=0, ifi_flags=0, ifi_change=0},
# * [
# * {{nla_len=8, nla_type=IFLA_LINK}, 2},
# * {{nla_len=12, nla_type=IFLA_IFNAME}, "xvlan22"},
# * {{nla_len=24, nla_type=IFLA_LINKINFO},
# * [
# * {{nla_len=8, nla_type=IFLA_INFO_KIND}, "vlan"...},
# * {{nla_len=12, nla_type=IFLA_INFO_DATA}, "\x06\x00\x01\x00\x16\x00\x00\x00"}]}]}, iov_len=76}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 76
# * {{nla_len=12, nla_type=IFLA_INFO_DATA}, "\x06\x00\x01\x00\x16\x00\x00\x00"}
# */
@pytest.mark.skip(reason="vlan support needs more work")
@pytest.mark.require_user("root")

144
tests/sys/netlink/test_rtnl_ifaddr.py Normal file
View File

@ -0,0 +1,144 @@
import ipaddress
import socket
import struct
from atf_python.sys.net.netlink import IfattrType
from atf_python.sys.net.netlink import NetlinkIfaMessage
from atf_python.sys.net.netlink import NetlinkTestTemplate
from atf_python.sys.net.netlink import NlConst
from atf_python.sys.net.netlink import NlHelper
from atf_python.sys.net.netlink import NlmBaseFlags
from atf_python.sys.net.netlink import NlMsgType
from atf_python.sys.net.netlink import NlRtMsgType
from atf_python.sys.net.netlink import Nlsock
from atf_python.sys.net.netlink import RtScope
from atf_python.sys.net.vnet import SingleVnetTestTemplate
class TestRtNlIfaddr(SingleVnetTestTemplate, NetlinkTestTemplate):
def setup_method(self, method):
method_name = method.__name__
if "4" in method_name:
self.IPV4_PREFIXES = ["192.0.2.1/24"]
if "6" in method_name:
self.IPV6_PREFIXES = ["2001:db8::1/64"]
super().setup_method(method)
self.setup_netlink(NlConst.NETLINK_ROUTE)
def test_46_nofilter(self):
"""Tests that listing outputs both IPv4/IPv6 and interfaces"""
msg = NetlinkIfaMessage(self.helper, NlRtMsgType.RTM_GETADDR.value)
msg.nl_hdr.nlmsg_flags = (
NlmBaseFlags.NLM_F_ACK.value | NlmBaseFlags.NLM_F_REQUEST.value
)
self.write_message(msg)
ret = []
for rx_msg in self.read_msg_list(msg.nl_hdr.nlmsg_seq, NlRtMsgType.RTM_NEWADDR):
ifname = socket.if_indextoname(rx_msg.base_hdr.ifa_index)
family = rx_msg.base_hdr.ifa_family
ret.append((ifname, family, rx_msg))
ifname = "lo0"
assert len([r for r in ret if r[0] == ifname]) > 0
ifname = self.vnet.iface_alias_map["if1"].name
assert len([r for r in ret if r[0] == ifname and r[1] == socket.AF_INET]) == 1
assert len([r for r in ret if r[0] == ifname and r[1] == socket.AF_INET6]) == 2
def test_46_filter_iface(self):
"""Tests that listing outputs both IPv4/IPv6 for the specific interface"""
epair_ifname = self.vnet.iface_alias_map["if1"].name
msg = NetlinkIfaMessage(self.helper, NlRtMsgType.RTM_GETADDR.value)
msg.nl_hdr.nlmsg_flags = (
NlmBaseFlags.NLM_F_ACK.value | NlmBaseFlags.NLM_F_REQUEST.value
)
msg.base_hdr.ifa_index = socket.if_nametoindex(epair_ifname)
self.write_message(msg)
ret = []
for rx_msg in self.read_msg_list(msg.nl_hdr.nlmsg_seq, NlRtMsgType.RTM_NEWADDR):
ifname = socket.if_indextoname(rx_msg.base_hdr.ifa_index)
family = rx_msg.base_hdr.ifa_family
ret.append((ifname, family, rx_msg))
ifname = epair_ifname
assert len([r for r in ret if r[0] == ifname and r[1] == socket.AF_INET]) == 1
assert len([r for r in ret if r[0] == ifname and r[1] == socket.AF_INET6]) == 2
assert len(ret) == 3
def filter_iface_family(self, family, num_items):
"""Tests that listing outputs IPv4 for the specific interface"""
epair_ifname = self.vnet.iface_alias_map["if1"].name
msg = NetlinkIfaMessage(self.helper, NlRtMsgType.RTM_GETADDR.value)
msg.nl_hdr.nlmsg_flags = (
NlmBaseFlags.NLM_F_ACK.value | NlmBaseFlags.NLM_F_REQUEST.value
)
msg.base_hdr.ifa_family = family
msg.base_hdr.ifa_index = socket.if_nametoindex(epair_ifname)
self.write_message(msg)
ret = []
for rx_msg in self.read_msg_list(msg.nl_hdr.nlmsg_seq, NlRtMsgType.RTM_NEWADDR):
assert family == rx_msg.base_hdr.ifa_family
assert epair_ifname == socket.if_indextoname(rx_msg.base_hdr.ifa_index)
ret.append(rx_msg)
assert len(ret) == num_items
return ret
def test_4_broadcast(self):
"""Tests header/attr output for listing IPv4 ifas on broadcast iface"""
ret = self.filter_iface_family(socket.AF_INET, 1)
# Should be 192.0.2.1/24
msg = ret[0]
# Family and ifindex has been checked already
assert msg.base_hdr.ifa_prefixlen == 24
# Ignore IFA_FLAGS for now
assert msg.base_hdr.ifa_scope == RtScope.RT_SCOPE_UNIVERSE.value
assert msg.get_nla(IfattrType.IFA_ADDRESS).addr == "192.0.2.1"
assert msg.get_nla(IfattrType.IFA_LOCAL).addr == "192.0.2.1"
assert msg.get_nla(IfattrType.IFA_BROADCAST).addr == "192.0.2.255"
epair_ifname = self.vnet.iface_alias_map["if1"].name
assert msg.get_nla(IfattrType.IFA_LABEL).text == epair_ifname
def test_6_broadcast(self):
"""Tests header/attr output for listing IPv6 ifas on broadcast iface"""
ret = self.filter_iface_family(socket.AF_INET6, 2)
# Should be 192.0.2.1/24
if ret[0].base_hdr.ifa_scope == RtScope.RT_SCOPE_UNIVERSE.value:
(gmsg, lmsg) = ret
else:
(lmsg, gmsg) = ret
# Start with global ( 2001:db8::1/64 )
msg = gmsg
# Family and ifindex has been checked already
assert msg.base_hdr.ifa_prefixlen == 64
# Ignore IFA_FLAGS for now
assert msg.base_hdr.ifa_scope == RtScope.RT_SCOPE_UNIVERSE.value
assert msg.get_nla(IfattrType.IFA_ADDRESS).addr == "2001:db8::1"
assert msg.get_nla(IfattrType.IFA_LOCAL) is None
assert msg.get_nla(IfattrType.IFA_BROADCAST) is None
epair_ifname = self.vnet.iface_alias_map["if1"].name
assert msg.get_nla(IfattrType.IFA_LABEL).text == epair_ifname
# Local: fe80::/64
msg = lmsg
assert msg.base_hdr.ifa_prefixlen == 64
# Ignore IFA_FLAGS for now
assert msg.base_hdr.ifa_scope == RtScope.RT_SCOPE_LINK.value
addr = ipaddress.ip_address(msg.get_nla(IfattrType.IFA_ADDRESS).addr)
assert addr.is_link_local
# Verify that ifindex is not emmbedded
assert struct.unpack("!H", addr.packed[2:4])[0] == 0
assert msg.get_nla(IfattrType.IFA_LOCAL) is None
assert msg.get_nla(IfattrType.IFA_BROADCAST) is None
epair_ifname = self.vnet.iface_alias_map["if1"].name
assert msg.get_nla(IfattrType.IFA_LABEL).text == epair_ifname