| // Copyright (c) 2011 The Chromium OS Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "shill/rtnl_message.h" |
| |
| #include <base/logging.h> |
| |
| #include <sys/socket.h> |
| #include <linux/netlink.h> |
| #include <linux/rtnetlink.h> |
| |
| namespace shill { |
| |
| struct RTNLHeader { |
| RTNLHeader() { |
| memset(this, 0, sizeof(*this)); |
| } |
| struct nlmsghdr hdr; |
| union { |
| struct ifinfomsg ifi; |
| struct ifaddrmsg ifa; |
| struct rtmsg rtm; |
| struct rtgenmsg gen; |
| }; |
| }; |
| |
| RTNLMessage::RTNLMessage() |
| : type_(kMessageTypeUnknown), |
| mode_(kMessageModeUnknown), |
| flags_(0), |
| interface_index_(0), |
| family_(IPAddress::kAddressFamilyUnknown) {} |
| |
| RTNLMessage::RTNLMessage(MessageType type, |
| MessageMode mode, |
| unsigned int flags, |
| uint32 seq, |
| uint32 pid, |
| int interface_index, |
| IPAddress::Family family) |
| : type_(type), |
| mode_(mode), |
| flags_(flags), |
| seq_(seq), |
| pid_(pid), |
| interface_index_(interface_index), |
| family_(family) {} |
| |
| bool RTNLMessage::Decode(const ByteString &msg) { |
| bool ret = DecodeInternal(msg); |
| if (!ret) { |
| mode_ = kMessageModeUnknown; |
| type_ = kMessageTypeUnknown; |
| } |
| return ret; |
| } |
| |
| bool RTNLMessage::DecodeInternal(const ByteString &msg) { |
| const RTNLHeader *hdr = |
| reinterpret_cast<const RTNLHeader *>(msg.GetConstData()); |
| |
| if (msg.GetLength() < sizeof(hdr->hdr) || |
| msg.GetLength() < hdr->hdr.nlmsg_len) |
| return false; |
| |
| MessageMode mode = kMessageModeUnknown; |
| switch (hdr->hdr.nlmsg_type) { |
| case RTM_NEWLINK: |
| case RTM_NEWADDR: |
| case RTM_NEWROUTE: |
| mode = kMessageModeAdd; |
| break; |
| |
| case RTM_DELLINK: |
| case RTM_DELADDR: |
| case RTM_DELROUTE: |
| mode = kMessageModeDelete; |
| break; |
| |
| default: |
| return false; |
| } |
| |
| rtattr *attr_data = NULL; |
| int attr_length = 0; |
| |
| switch (hdr->hdr.nlmsg_type) { |
| case RTM_NEWLINK: |
| case RTM_DELLINK: |
| if (!DecodeLink(hdr, mode, &attr_data, &attr_length)) |
| return false; |
| break; |
| |
| case RTM_NEWADDR: |
| case RTM_DELADDR: |
| if (!DecodeAddress(hdr, mode, &attr_data, &attr_length)) |
| return false; |
| break; |
| |
| case RTM_NEWROUTE: |
| case RTM_DELROUTE: |
| if (!DecodeRoute(hdr, mode, &attr_data, &attr_length)) |
| return false; |
| break; |
| |
| default: |
| NOTREACHED(); |
| } |
| |
| flags_ = hdr->hdr.nlmsg_flags; |
| seq_ = hdr->hdr.nlmsg_seq; |
| pid_ = hdr->hdr.nlmsg_pid; |
| |
| while (attr_data && RTA_OK(attr_data, attr_length)) { |
| SetAttribute( |
| attr_data->rta_type, |
| ByteString(reinterpret_cast<unsigned char *>(RTA_DATA(attr_data)), |
| RTA_PAYLOAD(attr_data))); |
| attr_data = RTA_NEXT(attr_data, attr_length); |
| } |
| |
| if (attr_length) { |
| // We hit a parse error while going through the attributes |
| attributes_.clear(); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| bool RTNLMessage::DecodeLink(const RTNLHeader *hdr, |
| MessageMode mode, |
| rtattr **attr_data, |
| int *attr_length) { |
| if (hdr->hdr.nlmsg_len < NLMSG_LENGTH(sizeof(hdr->ifi))) { |
| return false; |
| } |
| |
| mode_ = mode; |
| *attr_data = IFLA_RTA(NLMSG_DATA(&hdr->hdr)); |
| *attr_length = IFLA_PAYLOAD(&hdr->hdr); |
| |
| type_ = kMessageTypeLink; |
| family_ = hdr->ifi.ifi_family; |
| interface_index_ = hdr->ifi.ifi_index; |
| set_link_status(LinkStatus(hdr->ifi.ifi_type, |
| hdr->ifi.ifi_flags, |
| hdr->ifi.ifi_change)); |
| return true; |
| } |
| |
| bool RTNLMessage::DecodeAddress(const RTNLHeader *hdr, |
| MessageMode mode, |
| rtattr **attr_data, |
| int *attr_length) { |
| if (hdr->hdr.nlmsg_len < NLMSG_LENGTH(sizeof(hdr->ifa))) { |
| return false; |
| } |
| mode_ = mode; |
| *attr_data = IFA_RTA(NLMSG_DATA(&hdr->hdr)); |
| *attr_length = IFA_PAYLOAD(&hdr->hdr); |
| |
| type_ = kMessageTypeAddress; |
| family_ = hdr->ifa.ifa_family; |
| interface_index_ = hdr->ifa.ifa_index; |
| set_address_status(AddressStatus(hdr->ifa.ifa_prefixlen, |
| hdr->ifa.ifa_flags, |
| hdr->ifa.ifa_scope)); |
| return true; |
| } |
| |
| bool RTNLMessage::DecodeRoute(const RTNLHeader *hdr, |
| MessageMode mode, |
| rtattr **attr_data, |
| int *attr_length) { |
| if (hdr->hdr.nlmsg_len < NLMSG_LENGTH(sizeof(hdr->rtm))) { |
| return false; |
| } |
| mode_ = mode; |
| *attr_data = RTM_RTA(NLMSG_DATA(&hdr->hdr)); |
| *attr_length = RTM_PAYLOAD(&hdr->hdr); |
| |
| type_ = kMessageTypeRoute; |
| family_ = hdr->rtm.rtm_family; |
| set_route_status(RouteStatus(hdr->rtm.rtm_dst_len, |
| hdr->rtm.rtm_src_len, |
| hdr->rtm.rtm_table, |
| hdr->rtm.rtm_protocol, |
| hdr->rtm.rtm_scope, |
| hdr->rtm.rtm_type, |
| hdr->rtm.rtm_flags)); |
| return true; |
| } |
| |
| ByteString RTNLMessage::Encode() { |
| if (type_ != kMessageTypeLink && |
| type_ != kMessageTypeAddress && |
| type_ != kMessageTypeRoute) { |
| return ByteString(); |
| } |
| |
| RTNLHeader hdr; |
| hdr.hdr.nlmsg_flags = flags_; |
| hdr.hdr.nlmsg_seq = seq_; |
| hdr.hdr.nlmsg_pid = pid_; |
| hdr.hdr.nlmsg_seq = 0; |
| |
| if (mode_ == kMessageModeGet) { |
| if (type_ == kMessageTypeLink) { |
| hdr.hdr.nlmsg_type = RTM_GETLINK; |
| } else if (type_ == kMessageTypeAddress) { |
| hdr.hdr.nlmsg_type = RTM_GETADDR; |
| } else if (type_ == kMessageTypeRoute) { |
| hdr.hdr.nlmsg_type = RTM_GETROUTE; |
| } |
| hdr.hdr.nlmsg_len = NLMSG_LENGTH(sizeof(hdr.gen)); |
| hdr.gen.rtgen_family = family_; |
| } else { |
| switch (type_) { |
| case kMessageTypeLink: |
| EncodeLink(&hdr); |
| break; |
| |
| case kMessageTypeAddress: |
| EncodeAddress(&hdr); |
| break; |
| |
| case kMessageTypeRoute: |
| EncodeRoute(&hdr); |
| break; |
| |
| default: |
| NOTREACHED(); |
| } |
| } |
| |
| size_t header_length = hdr.hdr.nlmsg_len; |
| ByteString attributes; |
| |
| base::hash_map<uint16, ByteString>::iterator attr; |
| for (attr = attributes_.begin(); attr != attributes_.end(); ++attr) { |
| size_t len = RTA_LENGTH(attr->second.GetLength()); |
| hdr.hdr.nlmsg_len = NLMSG_ALIGN(hdr.hdr.nlmsg_len) + RTA_ALIGN(len); |
| |
| struct rtattr rt_attr = { len, attr->first }; |
| ByteString attr_header(reinterpret_cast<unsigned char *>(&rt_attr), |
| sizeof(rt_attr)); |
| attr_header.Resize(RTA_ALIGN(attr_header.GetLength())); |
| attributes.Append(attr_header); |
| |
| ByteString attr_data(attr->second); |
| attr_data.Resize(RTA_ALIGN(attr_data.GetLength())); |
| attributes.Append(attr_data); |
| } |
| |
| ByteString packet(reinterpret_cast<unsigned char *>(&hdr), header_length); |
| packet.Append(attributes); |
| |
| return packet; |
| } |
| |
| void RTNLMessage::EncodeLink(RTNLHeader *hdr) { |
| hdr->hdr.nlmsg_type = (mode_ == kMessageModeAdd) ? RTM_NEWLINK : RTM_DELLINK; |
| hdr->hdr.nlmsg_len = NLMSG_LENGTH(sizeof(hdr->ifi)); |
| hdr->ifi.ifi_family = family_; |
| hdr->ifi.ifi_type = link_status_.type; |
| hdr->ifi.ifi_flags = link_status_.flags; |
| hdr->ifi.ifi_change = link_status_.change; |
| } |
| |
| void RTNLMessage::EncodeAddress(RTNLHeader *hdr) { |
| hdr->hdr.nlmsg_type = (mode_ == kMessageModeAdd) ? RTM_NEWADDR : RTM_DELADDR; |
| hdr->hdr.nlmsg_len = NLMSG_LENGTH(sizeof(hdr->ifa)); |
| hdr->ifa.ifa_family = family_; |
| hdr->ifa.ifa_prefixlen = address_status_.prefix_len; |
| hdr->ifa.ifa_flags = address_status_.flags; |
| hdr->ifa.ifa_scope = address_status_.scope; |
| hdr->ifa.ifa_index = interface_index_; |
| } |
| |
| void RTNLMessage::EncodeRoute(RTNLHeader *hdr) { |
| hdr->hdr.nlmsg_type = |
| (mode_ == kMessageModeAdd) ? RTM_NEWROUTE : RTM_DELROUTE; |
| hdr->hdr.nlmsg_len = NLMSG_LENGTH(sizeof(hdr->rtm)); |
| hdr->rtm.rtm_family = family_; |
| hdr->rtm.rtm_dst_len = route_status_.dst_prefix; |
| hdr->rtm.rtm_src_len = route_status_.src_prefix; |
| hdr->rtm.rtm_table = route_status_.table; |
| hdr->rtm.rtm_protocol = route_status_.protocol; |
| hdr->rtm.rtm_scope = route_status_.scope; |
| hdr->rtm.rtm_type = route_status_.type; |
| hdr->rtm.rtm_flags = route_status_.flags; |
| } |
| |
| } // namespace shill |
