[PATCH] New getaddinfo implementation
Thorsten Kukuk
kukuk@suse.de
Wed Mar 26 10:17:00 GMT 2003
Hi,
I wrote a new getaddrinfo implementation for Linux, which uses the
netlink kernel interface and works with IPv6, too.
Thorsten
--
Thorsten Kukuk http://www.suse.de/~kukuk/ kukuk@suse.de
SuSE Linux AG Deutschherrnstr. 15-19 D-90429 Nuernberg
--------------------------------------------------------------------
Key fingerprint = A368 676B 5E1B 3E46 CFCE 2D97 F8FD 4E23 56C6 FB4B
-------------- next part --------------
2003-03-24 Thorsten Kukuk <kukuk@suse.de>
* sysdeps/unix/sysv/linux/Dist: add ifaddrs.c
* sysdeps/unix/sysv/linux/ifaddrs.c: New implementation for Linux
* inet/test-ifaddrs.c: Allow AF_PACKET.
--- sysdeps/unix/sysv/linux/Dist
+++ sysdeps/unix/sysv/linux/Dist 2003/03/24 10:09:13
@@ -5,6 +5,7 @@
exit-thread.S
getdirentries.c
getdirentries64.c
+ifaddrs.c
ipc_priv.h
kernel-features.h
kernel_sigaction.h
--- sysdeps/unix/sysv/linux/ifaddrs.c
+++ sysdeps/unix/sysv/linux/ifaddrs.c 2003/03/23 21:10:20
@@ -0,0 +1,595 @@
+/* getifaddrs -- get names and addresses of all network interfaces
+ Copyright (C) 2003 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <time.h>
+#include <errno.h>
+#include <net/if.h>
+#include <ifaddrs.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <netpacket/packet.h>
+
+#include <asm/types.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+#include <stdio.h>
+
+struct netlink_res {
+ struct netlink_res *next;
+ struct nlmsghdr *nlh;
+ size_t size; /* size of response. */
+ uint32_t seq; /* sequentiel number we used. */
+};
+
+struct netlink_handle {
+ int fd; /* netlink file descriptor. */
+ pid_t pid; /* Process ID. */
+ uint32_t seq; /* the sequentiell number we use currently. */
+ struct netlink_res *nlm_list; /* pointer to list of responses. */
+ struct netlink_res *end_ptr; /* for faster append of new entries. */
+};
+typedef struct netlink_handle netlink_handle;
+
+static void
+free_netlink_handle (netlink_handle *h)
+{
+ struct netlink_res *ptr;
+ int saved_errno = errno;
+
+ if (h->nlm_list == NULL)
+ return;
+
+ ptr = h->nlm_list;
+ while (ptr)
+ {
+ struct netlink_res *tmpptr;
+
+ if (ptr->nlh)
+ free (ptr->nlh);
+ tmpptr = ptr->next;
+ free (ptr);
+ ptr = tmpptr;
+ }
+
+ errno = saved_errno;
+}
+
+static int
+netlink_sendreq (netlink_handle *h, int type)
+{
+ struct {
+ struct nlmsghdr nlh;
+ struct rtgenmsg g;
+ } req;
+ struct sockaddr_nl nladdr;
+
+ if (h->seq == 0)
+ h->seq = time (NULL);
+
+ req.nlh.nlmsg_len = sizeof(req);
+ req.nlh.nlmsg_type = type;
+ req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
+ req.nlh.nlmsg_pid = 0;
+ req.nlh.nlmsg_seq = h->seq;
+ req.g.rtgen_family = AF_UNSPEC;
+
+ memset(&nladdr, 0, sizeof(nladdr));
+ nladdr.nl_family = AF_NETLINK;
+
+ return sendto (h->fd, (void*)&req, sizeof (req), 0,
+ (struct sockaddr*)&nladdr, sizeof (nladdr));
+}
+
+
+static int
+netlink_receive (struct netlink_handle *h)
+{
+ char buf[4096];
+ struct iovec iov = {buf, sizeof(buf)};
+ struct sockaddr_nl nladdr;
+ struct nlmsghdr *nh;
+ int read_len, done = 0;
+
+ while (!done)
+ {
+ struct msghdr msg = {
+ (void*)&nladdr, sizeof (nladdr),
+ &iov, 1,
+ NULL, 0,
+ 0
+ };
+
+ do {
+ read_len = recvmsg (h->fd, &msg, 0);
+ } while ((read_len < 0) && (errno == EINTR));
+
+ if (read_len < 0)
+ return -1;
+
+ if (msg.msg_flags & MSG_TRUNC)
+ return -1;
+
+ if (buf)
+ {
+ struct netlink_res *nlm_next =
+ (struct netlink_res *)malloc (sizeof (struct netlink_res));
+
+ if (nlm_next == NULL)
+ return -1;
+ else
+ {
+ nlm_next->next = NULL;
+ nlm_next->nlh = malloc (read_len);
+ memcpy (nlm_next->nlh, buf, read_len);
+ nlm_next->size = read_len;
+ nlm_next->seq = h->seq;
+ if (h->nlm_list == NULL)
+ {
+ h->nlm_list = nlm_next;
+ h->end_ptr = nlm_next;
+ }
+ else
+ {
+ h->end_ptr->next = nlm_next;
+ h->end_ptr = nlm_next;
+ }
+ }
+ }
+
+ for (nh = (struct nlmsghdr *)buf;
+ NLMSG_OK(nh, (size_t)read_len);
+ nh = (struct nlmsghdr *)NLMSG_NEXT(nh, read_len))
+ {
+ if ((pid_t)nh->nlmsg_pid != h->pid ||
+ nh->nlmsg_seq != h->seq)
+ continue;
+
+ if (nh->nlmsg_type == NLMSG_DONE)
+ {
+ /* we found the end, leave the loop. */
+ ++done;
+ break;
+ }
+ if (nh->nlmsg_type == NLMSG_ERROR)
+ {
+ struct nlmsgerr *nlerr = (struct nlmsgerr *)NLMSG_DATA(nh);
+ if (nh->nlmsg_len < NLMSG_LENGTH (sizeof(struct nlmsgerr)))
+ errno = EIO;
+ else
+ errno = -nlerr->error;
+ return -1;
+ }
+ }
+ }
+ return 0;
+}
+
+static void
+netlink_close (struct netlink_handle *h)
+{
+ /* save errno, so that netlink_close will not overwrite previous
+ error code. */
+ int saved_errno = errno;
+
+ close (h->fd);
+
+ errno = saved_errno;
+}
+
+static int
+netlink_open (struct netlink_handle *h)
+{
+ struct sockaddr_nl nladdr;
+
+ h->fd = socket (PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+ if (h->fd < 0)
+ return -1;
+
+ memset (&nladdr, 0, sizeof (nladdr));
+ nladdr.nl_family = AF_NETLINK;
+ if (bind (h->fd, (struct sockaddr*)&nladdr, sizeof(nladdr)) < 0)
+ {
+ netlink_close (h);
+ return -1;
+ }
+ return 0;
+}
+
+/* Create a linked list of `struct ifaddrs' structures, one for each
+ network interface on the host machine. If successful, store the
+ list in *IFAP and return 0. On errors, return -1 and set `errno'. */
+int
+getifaddrs (struct ifaddrs **ifap)
+{
+ netlink_handle nh = {0, 0, 0, NULL, NULL};
+ struct netlink_res *nlp;
+ struct ifaddrs *ifas;
+ uint32_t i, newlink, newaddr, newaddr_idx;
+
+ if (ifap)
+ *ifap = NULL;
+
+ if (netlink_open (&nh) < 0)
+ return -1;
+
+ nh.pid = getpid ();
+
+ if (netlink_sendreq (&nh, RTM_GETLINK) < 0)
+ {
+ netlink_close (&nh);
+ return -1;
+ }
+ if (netlink_receive (&nh) < 0)
+ {
+ netlink_close (&nh);
+ return -1;
+ }
+
+ ++nh.seq;
+ if (netlink_sendreq (&nh, RTM_GETADDR) < 0)
+ {
+ netlink_close (&nh);
+ return -1;
+ }
+ if (netlink_receive (&nh) < 0)
+ {
+ netlink_close (&nh);
+ return -1;
+ }
+
+ /* Count all RTM_NEWLINK entries to allocate enough
+ memory. */
+ newlink = newaddr = 0;
+ for (nlp = nh.nlm_list; nlp; nlp = nlp->next)
+ {
+ struct nlmsghdr *nlh;
+ size_t size = nlp->size;
+
+ if (nlp->nlh == NULL)
+ continue;
+
+ for (nlh = nlp->nlh; NLMSG_OK(nlh, size);
+ nlh = NLMSG_NEXT(nlh, size))
+ {
+ /* check if the message is what we want */
+ if ((pid_t)nlh->nlmsg_pid != nh.pid ||
+ nlh->nlmsg_seq != nlp->seq)
+ continue;
+
+ if (nlh->nlmsg_type == NLMSG_DONE)
+ break; /* ok */
+
+ if (nlh->nlmsg_type == RTM_NEWLINK)
+ ++newlink;
+ else if (nlh->nlmsg_type == RTM_NEWADDR)
+ ++newaddr;
+ }
+ }
+
+ if ((newlink + newaddr) == 0)
+ return 0;
+
+ /* allocate memory for all entries we have and set next pointer. */
+ ifas = calloc (newlink + newaddr, sizeof (struct ifaddrs));
+ for (i = 0; i < newlink + newaddr - 1; i++)
+ ifas[i].ifa_next = &ifas[i+1];
+
+ newaddr_idx = 0; /* counter for newaddr index. */
+
+ for (nlp = nh.nlm_list; nlp; nlp = nlp->next)
+ {
+ struct nlmsghdr *nlh;
+ size_t size = nlp->size;
+
+ if (nlp->nlh == NULL)
+ continue;
+
+ for (nlh = nlp->nlh; NLMSG_OK(nlh, size);
+ nlh = NLMSG_NEXT(nlh, size))
+ {
+ uint32_t ifa_index = 0;
+
+ /* check if the message is the one we want */
+ if ((pid_t)nlh->nlmsg_pid != nh.pid ||
+ nlh->nlmsg_seq != nlp->seq)
+ continue;
+
+ if (nlh->nlmsg_type == NLMSG_DONE)
+ break; /* ok */
+ else if (nlh->nlmsg_type == RTM_NEWLINK)
+ {
+ struct ifinfomsg *ifim = (struct ifinfomsg *)NLMSG_DATA(nlh);
+ struct rtattr *rta = IFLA_RTA(ifim);
+ size_t rtasize = IFLA_PAYLOAD(nlh);
+
+ ifa_index = ifim->ifi_index - 1;
+ ifas[ifa_index].ifa_flags = ifim->ifi_flags;
+
+ while (RTA_OK (rta, rtasize))
+ {
+ char *rta_data = RTA_DATA(rta);
+ size_t rta_payload = RTA_PAYLOAD(rta);
+
+ switch (rta->rta_type)
+ {
+ case IFLA_ADDRESS:
+ {
+ struct sockaddr_ll *sa_ll;
+ /* struct sockaddr_ll has 8 bytes. */
+ sa_ll = calloc (1, sizeof (struct sockaddr_ll));
+ ifas[ifa_index].ifa_addr = (struct sockaddr *)sa_ll;
+
+ sa_ll->sll_family = AF_PACKET;
+ memcpy(sa_ll->sll_addr, (char *)rta_data, rta_payload);
+ sa_ll->sll_halen = rta_payload;
+ sa_ll->sll_ifindex = ifim->ifi_index;
+ sa_ll->sll_hatype = ifim->ifi_type;
+ }
+ break;
+ case IFLA_BROADCAST:
+ {
+ struct sockaddr_ll *sa_ll;
+ /* struct sockaddr_ll has 8 bytes. */
+ sa_ll = calloc (1, sizeof (struct sockaddr_ll));
+ ifas[ifa_index].ifa_broadaddr =
+ (struct sockaddr *)sa_ll;
+
+ sa_ll->sll_family = AF_PACKET;
+ memcpy(sa_ll->sll_addr, (char *)rta_data, rta_payload);
+ sa_ll->sll_halen = rta_payload;
+ sa_ll->sll_ifindex = ifim->ifi_index;
+ sa_ll->sll_hatype = ifim->ifi_type;
+ }
+ break;
+ case IFLA_IFNAME:/* Name of Interface */
+ ifas[ifa_index].ifa_name = malloc (rta_payload + 1);
+ strncpy(ifas[ifa_index].ifa_name, rta_data, rta_payload);
+ ifas[ifa_index].ifa_name[rta_payload] = '\0';
+ break;
+ case IFLA_STATS:/* Statistics of Interface */
+ ifas[ifa_index].ifa_data = malloc (rta_payload);
+ memcpy (ifas[ifa_index].ifa_data, rta_data, rta_payload);
+ break;
+ case IFLA_UNSPEC:
+ break;
+ case IFLA_MTU:
+ break;
+ case IFLA_LINK:
+ break;
+ case IFLA_QDISC:
+ break;
+ default:
+ break;
+ }
+
+ rta = RTA_NEXT(rta, rtasize);
+ }
+ }
+ else if (nlh->nlmsg_type == RTM_NEWADDR)
+ {
+ struct ifaddrmsg *ifam = (struct ifaddrmsg *)NLMSG_DATA(nlh);
+ struct rtattr *rta = IFA_RTA (ifam);
+ size_t rtasize = IFA_PAYLOAD(nlh);
+
+ ifa_index = newlink + newaddr_idx;
+ ifas[ifa_index].ifa_flags = ifas[ifam->ifa_index - 1].ifa_flags;
+ ++newaddr_idx;
+
+ while (RTA_OK (rta, rtasize))
+ {
+ char *rta_data = RTA_DATA(rta);
+ size_t rta_payload = RTA_PAYLOAD(rta);
+
+ switch(rta->rta_type)
+ {
+ case IFA_ADDRESS:
+ {
+ struct sockaddr *sa;
+
+ sa = calloc (1, sizeof (struct sockaddr_storage));
+ if (ifas[ifa_index].ifa_addr != NULL)
+ /* P2P network. */
+ ifas[ifa_index].ifa_broadaddr = sa;
+ else
+ ifas[ifa_index].ifa_addr = sa;
+
+ sa->sa_family = ifam->ifa_family;
+ switch (ifam->ifa_family)
+ {
+ case AF_INET:
+ memcpy (&((struct sockaddr_in*)sa)->sin_addr,
+ rta_data, rta_payload);
+ break;
+ case AF_INET6:
+ memcpy (&((struct sockaddr_in6*)sa)->sin6_addr,
+ rta_data, rta_payload);
+ if (IN6_IS_ADDR_LINKLOCAL(rta_data) ||
+ IN6_IS_ADDR_MC_LINKLOCAL(rta_data))
+ ((struct sockaddr_in6*)sa)->sin6_scope_id =
+ ifam->ifa_scope;
+ break;
+ default:
+ memcpy (sa->sa_data, rta_data, rta_payload);
+ break;
+ }
+ }
+ break;
+ case IFA_LOCAL:
+ {
+ struct sockaddr *sa;
+
+ if (ifas[ifa_index].ifa_addr != NULL)
+ /* Could be a P2P network. Move address to
+ correct field. */
+ ifas[ifa_index].ifa_broadaddr =
+ ifas[ifa_index].ifa_addr;
+
+ sa = calloc (1, sizeof (struct sockaddr_storage));
+ ifas[ifa_index].ifa_addr = sa;
+ sa->sa_family = ifam->ifa_family;
+ switch (ifam->ifa_family)
+ {
+ case AF_INET:
+ memcpy (&((struct sockaddr_in*)sa)->sin_addr,
+ rta_data, rta_payload);
+ break;
+ case AF_INET6:
+ memcpy (&((struct sockaddr_in6*)sa)->sin6_addr,
+ rta_data, rta_payload);
+ if (IN6_IS_ADDR_LINKLOCAL(rta_data) ||
+ IN6_IS_ADDR_MC_LINKLOCAL(rta_data))
+ ((struct sockaddr_in6*)sa)->sin6_scope_id =
+ ifam->ifa_scope;
+ break;
+ default:
+ memcpy (sa->sa_data, rta_data, rta_payload);
+ break;
+ }
+ }
+ break;
+ case IFA_BROADCAST:
+ {
+ struct sockaddr *sa;
+
+ /* We get IFA_BROADCAST, so IFA_LOCAL was to much. */
+ if (ifas[ifa_index].ifa_broadaddr != NULL)
+ free (ifas[ifa_index].ifa_broadaddr);
+
+ sa = calloc (1, sizeof (struct sockaddr_storage));
+ ifas[ifa_index].ifa_broadaddr = sa;
+ sa->sa_family = ifam->ifa_family;
+ switch (ifam->ifa_family)
+ {
+ case AF_INET:
+ memcpy (&((struct sockaddr_in*)sa)->sin_addr,
+ rta_data, rta_payload);
+ break;
+ case AF_INET6:
+ memcpy (&((struct sockaddr_in6*)sa)->sin6_addr,
+ rta_data, rta_payload);
+ if (IN6_IS_ADDR_LINKLOCAL(rta_data) ||
+ IN6_IS_ADDR_MC_LINKLOCAL(rta_data))
+ ((struct sockaddr_in6*)sa)->sin6_scope_id =
+ ifam->ifa_scope;
+ break;
+ default:
+ memcpy (sa->sa_data, rta_data, rta_payload);
+ break;
+ }
+ }
+ break;
+ case IFA_LABEL:
+ ifas[ifa_index].ifa_name = malloc (rta_payload + 1);
+ strncpy (ifas[ifa_index].ifa_name, rta_data, rta_payload);
+ ifas[ifa_index].ifa_name[rta_payload] = '\0';
+ break;
+ case IFA_UNSPEC:
+ break;
+ case IFA_CACHEINFO:
+ break;
+ default:
+ break;
+ }
+
+ rta = RTA_NEXT(rta, rtasize);
+ }
+
+ if (ifas[ifa_index].ifa_name == NULL)
+ ifas[ifa_index].ifa_name =
+ strdup (ifas[ifam->ifa_index - 1].ifa_name);
+
+ if (ifas[ifa_index].ifa_addr &&
+ ifas[ifa_index].ifa_addr->sa_family != AF_UNSPEC &&
+ ifas[ifa_index].ifa_addr->sa_family != AF_PACKET)
+ {
+ uint32_t max_prefixlen = 0;
+ char *cp = NULL;
+
+ ifas[ifa_index].ifa_netmask =
+ calloc (1, sizeof (struct sockaddr_storage));
+ switch (ifas[ifa_index].ifa_addr->sa_family)
+ {
+ case AF_INET:
+ cp = (char *)&((struct sockaddr_in*)ifas[ifa_index].ifa_netmask)->sin_addr;
+ max_prefixlen = 32;
+ break;
+ case AF_INET6:
+ cp = (char *)&((struct sockaddr_in6*)ifas[ifa_index].ifa_netmask)->sin6_addr;
+ max_prefixlen = 128;
+ break;
+ }
+ ifas[ifa_index].ifa_netmask->sa_family = ifas[ifa_index].ifa_addr->sa_family;
+ if (cp)
+ {
+ char c;
+ unsigned int preflen;
+
+ if ((max_prefixlen > 0) &&
+ (ifam->ifa_prefixlen > max_prefixlen))
+ preflen = max_prefixlen;
+ else
+ preflen = ifam->ifa_prefixlen;
+
+ for (i = 0; i < (preflen / 8); i++)
+ *cp++ = 0xff;
+ c = 0xff;
+ c <<= (8 - (preflen % 8));
+ *cp = c;
+ }
+ }
+ }
+ }
+ }
+
+ free_netlink_handle (&nh);
+ netlink_close (&nh);
+ if (ifap != NULL)
+ *ifap = ifas;
+
+ return 0;
+}
+
+void
+freeifaddrs (struct ifaddrs *ifa)
+{
+ struct ifaddrs *ptr;
+
+ ptr = ifa;
+ while (ptr)
+ {
+ if (ptr->ifa_name)
+ free (ptr->ifa_name);
+ if (ptr->ifa_addr)
+ free (ptr->ifa_addr);
+ if (ptr->ifa_netmask)
+ free (ptr->ifa_netmask);
+ if (ptr->ifa_broadaddr)
+ free (ptr->ifa_broadaddr);
+ if (ptr->ifa_data)
+ free (ptr->ifa_data);
+ ptr = ptr->ifa_next;
+ }
+
+ free (ifa);
+}
--- inet/test-ifaddrs.c
+++ inet/test-ifaddrs.c 2003/03/24 13:33:14
@@ -69,6 +69,10 @@
#endif
case AF_UNSPEC:
return "---";
+
+ case AF_PACKET:
+ return "<packet>";
+
default:
++failures;
printf ("sa_family=%d %08x\n", sa->sa_family,
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