--- /dev/null
+/*
+Copyright (c) 2013, Kenneth MacKay
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+ * Redistributions of source code must retain the above copyright notice, this
+ list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include "ifaddrs.h"
+
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <net/if_arp.h>
+#include <netinet/in.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+typedef struct NetlinkList
+{
+ struct NetlinkList *m_next;
+ struct nlmsghdr *m_data;
+ unsigned int m_size;
+} NetlinkList;
+
+static int netlink_socket(void)
+{
+ int l_socket = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+ if(l_socket < 0)
+ {
+ return -1;
+ }
+
+ struct sockaddr_nl l_addr;
+ memset(&l_addr, 0, sizeof(l_addr));
+ l_addr.nl_family = AF_NETLINK;
+ if(bind(l_socket, (struct sockaddr *)&l_addr, sizeof(l_addr)) < 0)
+ {
+ close(l_socket);
+ return -1;
+ }
+
+ return l_socket;
+}
+
+static int netlink_send(int p_socket, int p_request)
+{
+ char l_buffer[NLMSG_ALIGN(sizeof(struct nlmsghdr)) + NLMSG_ALIGN(sizeof(struct rtgenmsg))];
+ memset(l_buffer, 0, sizeof(l_buffer));
+ struct nlmsghdr *l_hdr = (struct nlmsghdr *)l_buffer;
+ struct rtgenmsg *l_msg = (struct rtgenmsg *)NLMSG_DATA(l_hdr);
+
+ l_hdr->nlmsg_len = NLMSG_LENGTH(sizeof(*l_msg));
+ l_hdr->nlmsg_type = p_request;
+ l_hdr->nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
+ l_hdr->nlmsg_pid = 0;
+ l_hdr->nlmsg_seq = p_socket;
+ l_msg->rtgen_family = AF_UNSPEC;
+
+ struct sockaddr_nl l_addr;
+ memset(&l_addr, 0, sizeof(l_addr));
+ l_addr.nl_family = AF_NETLINK;
+ return (sendto(p_socket, l_hdr, l_hdr->nlmsg_len, 0, (struct sockaddr *)&l_addr, sizeof(l_addr)));
+}
+
+static int netlink_recv(int p_socket, void *p_buffer, size_t p_len)
+{
+ struct msghdr l_msg;
+ struct iovec l_iov = { p_buffer, p_len };
+ struct sockaddr_nl l_addr;
+
+ for(;;)
+ {
+ l_msg.msg_name = (void *)&l_addr;
+ l_msg.msg_namelen = sizeof(l_addr);
+ l_msg.msg_iov = &l_iov;
+ l_msg.msg_iovlen = 1;
+ l_msg.msg_control = NULL;
+ l_msg.msg_controllen = 0;
+ l_msg.msg_flags = 0;
+ int l_result = recvmsg(p_socket, &l_msg, 0);
+
+ if(l_result < 0)
+ {
+ if(errno == EINTR)
+ {
+ continue;
+ }
+ return -2;
+ }
+
+ if(l_msg.msg_flags & MSG_TRUNC)
+ { // buffer was too small
+ return -1;
+ }
+ return l_result;
+ }
+}
+
+static struct nlmsghdr *getNetlinkResponse(int p_socket, int *p_size, int *p_done)
+{
+ size_t l_size = 4096;
+ void *l_buffer = NULL;
+
+ for(;;)
+ {
+ free(l_buffer);
+ l_buffer = malloc(l_size);
+
+ int l_read = netlink_recv(p_socket, l_buffer, l_size);
+ *p_size = l_read;
+ if(l_read == -2)
+ {
+ free(l_buffer);
+ return NULL;
+ }
+ if(l_read >= 0)
+ {
+ pid_t l_pid = getpid();
+ struct nlmsghdr *l_hdr;
+ for(l_hdr = (struct nlmsghdr *)l_buffer; NLMSG_OK(l_hdr, (unsigned int)l_read); l_hdr = (struct nlmsghdr *)NLMSG_NEXT(l_hdr, l_read))
+ {
+ if((pid_t)l_hdr->nlmsg_pid != l_pid || (int)l_hdr->nlmsg_seq != p_socket)
+ {
+ continue;
+ }
+
+ if(l_hdr->nlmsg_type == NLMSG_DONE)
+ {
+ *p_done = 1;
+ break;
+ }
+
+ if(l_hdr->nlmsg_type == NLMSG_ERROR)
+ {
+ free(l_buffer);
+ return NULL;
+ }
+ }
+ return l_buffer;
+ }
+
+ l_size *= 2;
+ }
+}
+
+static NetlinkList *newListItem(struct nlmsghdr *p_data, unsigned int p_size)
+{
+ NetlinkList *l_item = malloc(sizeof(NetlinkList));
+ l_item->m_next = NULL;
+ l_item->m_data = p_data;
+ l_item->m_size = p_size;
+ return l_item;
+}
+
+static void freeResultList(NetlinkList *p_list)
+{
+ NetlinkList *l_cur;
+ while(p_list)
+ {
+ l_cur = p_list;
+ p_list = p_list->m_next;
+ free(l_cur->m_data);
+ free(l_cur);
+ }
+}
+
+static NetlinkList *getResultList(int p_socket, int p_request)
+{
+ if(netlink_send(p_socket, p_request) < 0)
+ {
+ return NULL;
+ }
+
+ NetlinkList *l_list = NULL;
+ NetlinkList *l_end = NULL;
+ int l_size;
+ int l_done = 0;
+ while(!l_done)
+ {
+ struct nlmsghdr *l_hdr = getNetlinkResponse(p_socket, &l_size, &l_done);
+ if(!l_hdr)
+ { // error
+ freeResultList(l_list);
+ return NULL;
+ }
+
+ NetlinkList *l_item = newListItem(l_hdr, l_size);
+ if(!l_list)
+ {
+ l_list = l_item;
+ }
+ else
+ {
+ l_end->m_next = l_item;
+ }
+ l_end = l_item;
+ }
+ return l_list;
+}
+
+static size_t maxSize(size_t a, size_t b)
+{
+ return (a > b ? a : b);
+}
+
+static size_t calcAddrLen(sa_family_t p_family, int p_dataSize)
+{
+ switch(p_family)
+ {
+ case AF_INET:
+ return sizeof(struct sockaddr_in);
+ case AF_INET6:
+ return sizeof(struct sockaddr_in6);
+ case AF_PACKET:
+ return maxSize(sizeof(struct sockaddr_ll), offsetof(struct sockaddr_ll, sll_addr) + p_dataSize);
+ default:
+ return maxSize(sizeof(struct sockaddr), offsetof(struct sockaddr, sa_data) + p_dataSize);
+ }
+}
+
+static void makeSockaddr(sa_family_t p_family, struct sockaddr *p_dest, void *p_data, size_t p_size)
+{
+ switch(p_family)
+ {
+ case AF_INET:
+ memcpy(&((struct sockaddr_in*)p_dest)->sin_addr, p_data, p_size);
+ break;
+ case AF_INET6:
+ memcpy(&((struct sockaddr_in6*)p_dest)->sin6_addr, p_data, p_size);
+ break;
+ case AF_PACKET:
+ memcpy(((struct sockaddr_ll*)p_dest)->sll_addr, p_data, p_size);
+ ((struct sockaddr_ll*)p_dest)->sll_halen = p_size;
+ break;
+ default:
+ memcpy(p_dest->sa_data, p_data, p_size);
+ break;
+ }
+ p_dest->sa_family = p_family;
+}
+
+static void addToEnd(struct ifaddrs **p_resultList, struct ifaddrs *p_entry)
+{
+ if(!*p_resultList)
+ {
+ *p_resultList = p_entry;
+ }
+ else
+ {
+ struct ifaddrs *l_cur = *p_resultList;
+ while(l_cur->ifa_next)
+ {
+ l_cur = l_cur->ifa_next;
+ }
+ l_cur->ifa_next = p_entry;
+ }
+}
+
+static void interpretLink(struct nlmsghdr *p_hdr, struct ifaddrs **p_links, struct ifaddrs **p_resultList)
+{
+ struct ifinfomsg *l_info = (struct ifinfomsg *)NLMSG_DATA(p_hdr);
+
+ size_t l_nameSize = 0;
+ size_t l_addrSize = 0;
+ size_t l_dataSize = 0;
+
+ size_t l_rtaSize = NLMSG_PAYLOAD(p_hdr, sizeof(struct ifinfomsg));
+ struct rtattr *l_rta;
+ for(l_rta = (struct rtattr *)(((char *)l_info) + NLMSG_ALIGN(sizeof(struct ifinfomsg))); RTA_OK(l_rta, l_rtaSize); l_rta = RTA_NEXT(l_rta, l_rtaSize))
+ {
+ size_t l_rtaDataSize = RTA_PAYLOAD(l_rta);
+ switch(l_rta->rta_type)
+ {
+ case IFLA_ADDRESS:
+ case IFLA_BROADCAST:
+ l_addrSize += NLMSG_ALIGN(calcAddrLen(AF_PACKET, l_rtaDataSize));
+ break;
+ case IFLA_IFNAME:
+ l_nameSize += NLMSG_ALIGN(l_rtaSize + 1);
+ break;
+ case IFLA_STATS:
+ l_dataSize += NLMSG_ALIGN(l_rtaSize);
+ break;
+ default:
+ break;
+ }
+ }
+
+ struct ifaddrs *l_entry = malloc(sizeof(struct ifaddrs) + l_nameSize + l_addrSize + l_dataSize);
+ memset(l_entry, 0, sizeof(struct ifaddrs));
+ l_entry->ifa_name = "";
+
+ char *l_name = ((char *)l_entry) + sizeof(struct ifaddrs);
+ char *l_addr = l_name + l_nameSize;
+ char *l_data = l_addr + l_addrSize;
+
+ l_entry->ifa_flags = l_info->ifi_flags;
+
+ l_rtaSize = NLMSG_PAYLOAD(p_hdr, sizeof(struct ifinfomsg));
+ for(l_rta = (struct rtattr *)(((char *)l_info) + NLMSG_ALIGN(sizeof(struct ifinfomsg))); RTA_OK(l_rta, l_rtaSize); l_rta = RTA_NEXT(l_rta, l_rtaSize))
+ {
+ void *l_rtaData = RTA_DATA(l_rta);
+ size_t l_rtaDataSize = RTA_PAYLOAD(l_rta);
+ switch(l_rta->rta_type)
+ {
+ case IFLA_ADDRESS:
+ case IFLA_BROADCAST:
+ {
+ size_t l_addrLen = calcAddrLen(AF_PACKET, l_rtaDataSize);
+ makeSockaddr(AF_PACKET, (struct sockaddr *)l_addr, l_rtaData, l_rtaDataSize);
+ ((struct sockaddr_ll *)l_addr)->sll_ifindex = l_info->ifi_index;
+ ((struct sockaddr_ll *)l_addr)->sll_hatype = l_info->ifi_type;
+ if(l_rta->rta_type == IFLA_ADDRESS)
+ {
+ l_entry->ifa_addr = (struct sockaddr *)l_addr;
+ }
+ else
+ {
+ l_entry->ifa_broadaddr = (struct sockaddr *)l_addr;
+ }
+ l_addr += NLMSG_ALIGN(l_addrLen);
+ break;
+ }
+ case IFLA_IFNAME:
+ strncpy(l_name, l_rtaData, l_rtaDataSize);
+ l_name[l_rtaDataSize] = '\0';
+ l_entry->ifa_name = l_name;
+ break;
+ case IFLA_STATS:
+ memcpy(l_data, l_rtaData, l_rtaDataSize);
+ l_entry->ifa_data = l_data;
+ break;
+ default:
+ break;
+ }
+ }
+
+ addToEnd(p_resultList, l_entry);
+ p_links[l_info->ifi_index - 1] = l_entry;
+}
+
+static void interpretAddr(struct nlmsghdr *p_hdr, struct ifaddrs **p_links, struct ifaddrs **p_resultList)
+{
+ struct ifaddrmsg *l_info = (struct ifaddrmsg *)NLMSG_DATA(p_hdr);
+
+ size_t l_nameSize = 0;
+ size_t l_addrSize = 0;
+
+ int l_addedNetmask = 0;
+
+ size_t l_rtaSize = NLMSG_PAYLOAD(p_hdr, sizeof(struct ifaddrmsg));
+ struct rtattr *l_rta;
+ for(l_rta = (struct rtattr *)(((char *)l_info) + NLMSG_ALIGN(sizeof(struct ifaddrmsg))); RTA_OK(l_rta, l_rtaSize); l_rta = RTA_NEXT(l_rta, l_rtaSize))
+ {
+ size_t l_rtaDataSize = RTA_PAYLOAD(l_rta);
+ if(l_info->ifa_family == AF_PACKET)
+ {
+ continue;
+ }
+
+ switch(l_rta->rta_type)
+ {
+ case IFA_ADDRESS:
+ case IFA_LOCAL:
+ if((l_info->ifa_family == AF_INET || l_info->ifa_family == AF_INET6) && !l_addedNetmask)
+ { // make room for netmask
+ l_addrSize += NLMSG_ALIGN(calcAddrLen(l_info->ifa_family, l_rtaDataSize));
+ l_addedNetmask = 1;
+ }
+ case IFA_BROADCAST:
+ l_addrSize += NLMSG_ALIGN(calcAddrLen(l_info->ifa_family, l_rtaDataSize));
+ break;
+ case IFA_LABEL:
+ l_nameSize += NLMSG_ALIGN(l_rtaSize + 1);
+ break;
+ default:
+ break;
+ }
+ }
+
+ struct ifaddrs *l_entry = malloc(sizeof(struct ifaddrs) + l_nameSize + l_addrSize);
+ memset(l_entry, 0, sizeof(struct ifaddrs));
+ l_entry->ifa_name = p_links[l_info->ifa_index - 1]->ifa_name;
+
+ char *l_name = ((char *)l_entry) + sizeof(struct ifaddrs);
+ char *l_addr = l_name + l_nameSize;
+
+ l_entry->ifa_flags = l_info->ifa_flags | p_links[l_info->ifa_index - 1]->ifa_flags;
+
+ l_rtaSize = NLMSG_PAYLOAD(p_hdr, sizeof(struct ifaddrmsg));
+ for(l_rta = (struct rtattr *)(((char *)l_info) + NLMSG_ALIGN(sizeof(struct ifaddrmsg))); RTA_OK(l_rta, l_rtaSize); l_rta = RTA_NEXT(l_rta, l_rtaSize))
+ {
+ void *l_rtaData = RTA_DATA(l_rta);
+ size_t l_rtaDataSize = RTA_PAYLOAD(l_rta);
+ switch(l_rta->rta_type)
+ {
+ case IFA_ADDRESS:
+ case IFA_BROADCAST:
+ case IFA_LOCAL:
+ {
+ size_t l_addrLen = calcAddrLen(l_info->ifa_family, l_rtaDataSize);
+ makeSockaddr(l_info->ifa_family, (struct sockaddr *)l_addr, l_rtaData, l_rtaDataSize);
+ if(l_info->ifa_family == AF_INET6)
+ {
+ if(IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)l_rtaData) || IN6_IS_ADDR_MC_LINKLOCAL((struct in6_addr *)l_rtaData))
+ {
+ ((struct sockaddr_in6 *)l_addr)->sin6_scope_id = l_info->ifa_index;
+ }
+ }
+
+ if(l_rta->rta_type == IFA_ADDRESS)
+ { // apparently in a point-to-point network IFA_ADDRESS contains the dest address and IFA_LOCAL contains the local address
+ if(l_entry->ifa_addr)
+ {
+ l_entry->ifa_dstaddr = (struct sockaddr *)l_addr;
+ }
+ else
+ {
+ l_entry->ifa_addr = (struct sockaddr *)l_addr;
+ }
+ }
+ else if(l_rta->rta_type == IFA_LOCAL)
+ {
+ if(l_entry->ifa_addr)
+ {
+ l_entry->ifa_dstaddr = l_entry->ifa_addr;
+ }
+ l_entry->ifa_addr = (struct sockaddr *)l_addr;
+ }
+ else
+ {
+ l_entry->ifa_broadaddr = (struct sockaddr *)l_addr;
+ }
+ l_addr += NLMSG_ALIGN(l_addrLen);
+ break;
+ }
+ case IFA_LABEL:
+ strncpy(l_name, l_rtaData, l_rtaDataSize);
+ l_name[l_rtaDataSize] = '\0';
+ l_entry->ifa_name = l_name;
+ break;
+ default:
+ break;
+ }
+ }
+
+ if(l_entry->ifa_addr && (l_entry->ifa_addr->sa_family == AF_INET || l_entry->ifa_addr->sa_family == AF_INET6))
+ {
+ unsigned l_maxPrefix = (l_entry->ifa_addr->sa_family == AF_INET ? 32 : 128);
+ unsigned l_prefix = (l_info->ifa_prefixlen > l_maxPrefix ? l_maxPrefix : l_info->ifa_prefixlen);
+ char l_mask[16] = {0};
+ unsigned i;
+ for(i=0; i<(l_prefix/8); ++i)
+ {
+ l_mask[i] = 0xff;
+ }
+ if (l_prefix % 8) {
+ l_mask[i] = 0xff << (8 - (l_prefix % 8));
+ }
+
+ makeSockaddr(l_entry->ifa_addr->sa_family, (struct sockaddr *)l_addr, l_mask, l_maxPrefix / 8);
+ l_entry->ifa_netmask = (struct sockaddr *)l_addr;
+ }
+
+ addToEnd(p_resultList, l_entry);
+}
+
+static void interpret(int p_socket, NetlinkList *p_netlinkList, struct ifaddrs **p_links, struct ifaddrs **p_resultList)
+{
+ pid_t l_pid = getpid();
+ for(; p_netlinkList; p_netlinkList = p_netlinkList->m_next)
+ {
+ unsigned int l_nlsize = p_netlinkList->m_size;
+ struct nlmsghdr *l_hdr;
+ for(l_hdr = p_netlinkList->m_data; NLMSG_OK(l_hdr, l_nlsize); l_hdr = NLMSG_NEXT(l_hdr, l_nlsize))
+ {
+ if((pid_t)l_hdr->nlmsg_pid != l_pid || (int)l_hdr->nlmsg_seq != p_socket)
+ {
+ continue;
+ }
+
+ if(l_hdr->nlmsg_type == NLMSG_DONE)
+ {
+ break;
+ }
+
+ if(l_hdr->nlmsg_type == RTM_NEWLINK)
+ {
+ interpretLink(l_hdr, p_links, p_resultList);
+ }
+ else if(l_hdr->nlmsg_type == RTM_NEWADDR)
+ {
+ interpretAddr(l_hdr, p_links, p_resultList);
+ }
+ }
+ }
+}
+
+static unsigned countLinks(int p_socket, NetlinkList *p_netlinkList)
+{
+ unsigned l_links = 0;
+ pid_t l_pid = getpid();
+ for(; p_netlinkList; p_netlinkList = p_netlinkList->m_next)
+ {
+ unsigned int l_nlsize = p_netlinkList->m_size;
+ struct nlmsghdr *l_hdr;
+ for(l_hdr = p_netlinkList->m_data; NLMSG_OK(l_hdr, l_nlsize); l_hdr = NLMSG_NEXT(l_hdr, l_nlsize))
+ {
+ if((pid_t)l_hdr->nlmsg_pid != l_pid || (int)l_hdr->nlmsg_seq != p_socket)
+ {
+ continue;
+ }
+
+ if(l_hdr->nlmsg_type == NLMSG_DONE)
+ {
+ break;
+ }
+
+ if(l_hdr->nlmsg_type == RTM_NEWLINK)
+ {
+ ++l_links;
+ }
+ }
+ }
+
+ return l_links;
+}
+
+int getifaddrs(struct ifaddrs **ifap)
+{
+ if(!ifap)
+ {
+ return -1;
+ }
+ *ifap = NULL;
+
+ int l_socket = netlink_socket();
+ if(l_socket < 0)
+ {
+ return -1;
+ }
+
+ NetlinkList *l_linkResults = getResultList(l_socket, RTM_GETLINK);
+ if(!l_linkResults)
+ {
+ close(l_socket);
+ return -1;
+ }
+
+ NetlinkList *l_addrResults = getResultList(l_socket, RTM_GETADDR);
+ if(!l_addrResults)
+ {
+ close(l_socket);
+ freeResultList(l_linkResults);
+ return -1;
+ }
+
+ unsigned l_numLinks = countLinks(l_socket, l_linkResults) + countLinks(l_socket, l_addrResults);
+ struct ifaddrs *l_links[l_numLinks];
+ memset(l_links, 0, l_numLinks * sizeof(struct ifaddrs *));
+
+ interpret(l_socket, l_linkResults, l_links, ifap);
+ interpret(l_socket, l_addrResults, l_links, ifap);
+
+ freeResultList(l_linkResults);
+ freeResultList(l_addrResults);
+ close(l_socket);
+ return 0;
+}
+
+void freeifaddrs(struct ifaddrs *ifa)
+{
+ struct ifaddrs *l_cur;
+ while(ifa)
+ {
+ l_cur = ifa;
+ ifa = ifa->ifa_next;
+ free(l_cur);
+ }
+}
projects / mirror_lxc.git / commitdiff