diff options
Diffstat (limited to 'sysdeps/unix')
| -rw-r--r-- | sysdeps/unix/sysv/linux/ifaddrs.c | 770 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/kernel-features.h | 6 |
2 files changed, 776 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/ifaddrs.c b/sysdeps/unix/sysv/linux/ifaddrs.c new file mode 100644 index 0000000000..3921c40dc7 --- /dev/null +++ b/sysdeps/unix/sysv/linux/ifaddrs.c @@ -0,0 +1,770 @@ +/* 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 <assert.h> +#include <errno.h> +#include <ifaddrs.h> +#include <net/if.h> +#include <netinet/in.h> +#include <netpacket/packet.h> +#include <stdbool.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> +#include <sys/socket.h> +#include <sysdep.h> +#include <time.h> +#include <unistd.h> + +#include <asm/types.h> +#include <linux/netlink.h> +#include <linux/rtnetlink.h> + +#include "kernel-features.h" + +/* We don't know if we have NETLINK support compiled in in our + Kernel, so include the old implementation as fallback. */ +#if __ASSUME_NETLINK_SUPPORT == 0 +static int no_netlink_support; + +#define getifaddrs fallback_getifaddrs +#include "sysdeps/gnu/ifaddrs.c" +#undef getifaddrs + +#endif + + +struct netlink_res +{ + struct netlink_res *next; + struct nlmsghdr *nlh; + size_t size; /* Size of response. */ + uint32_t seq; /* sequential number we used. */ +}; + + +struct netlink_handle +{ + int fd; /* Netlink file descriptor. */ + pid_t pid; /* Process ID. */ + uint32_t seq; /* The sequence 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. */ +}; + + +/* struct to hold the data for one ifaddrs entry, so we can allocate + everything at once. */ +struct ifaddrs_storage +{ + struct ifaddrs ifa; + union + { + /* Save space for the biggest of the four used sockaddr types and + avoid a lot of casts. */ + struct sockaddr sa; + struct sockaddr_ll sl; + struct sockaddr_in s4; + struct sockaddr_in6 s6; + } addr, netmask, broadaddr; + char name[IF_NAMESIZE + 1]; +}; + + +static void +free_netlink_handle (struct netlink_handle *h) +{ + struct netlink_res *ptr; + int saved_errno = errno; + + ptr = h->nlm_list; + while (ptr != NULL) + { + struct netlink_res *tmpptr; + + free (ptr->nlh); + tmpptr = ptr->next; + free (ptr); + ptr = tmpptr; + } + + errno = saved_errno; +} + + +static int +netlink_sendreq (struct 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 TEMP_FAILURE_RETRY (sendto (h->fd, (void *) &req, sizeof (req), 0, + (struct sockaddr *) &nladdr, + sizeof (nladdr))); +} + + +static int +netlink_receive (struct netlink_handle *h) +{ + struct netlink_res *nlm_next; + char buf[4096]; + struct iovec iov = { buf, sizeof (buf) }; + struct sockaddr_nl nladdr; + struct nlmsghdr *nlmh; + int read_len; + bool done = false; + + while (! done) + { + struct msghdr msg = + { + (void *) &nladdr, sizeof (nladdr), + &iov, 1, + NULL, 0, + 0 + }; + + read_len = TEMP_FAILURE_RETRY (recvmsg (h->fd, &msg, 0)); + if (read_len < 0) + return -1; + + if (msg.msg_flags & MSG_TRUNC) + return -1; + + nlm_next = (struct netlink_res *) malloc (sizeof (struct netlink_res)); + if (nlm_next == NULL) + return -1; + nlm_next->next = NULL; + nlm_next->nlh = (struct nlmsghdr *) malloc (read_len); + if (nlm_next->nlh == NULL) + { + free (nlm_next); + return -1; + } + 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 (nlmh = (struct nlmsghdr *) buf; + NLMSG_OK (nlmh, (size_t) read_len); + nlmh = (struct nlmsghdr *) NLMSG_NEXT (nlmh, read_len)) + { + if ((pid_t) nlmh->nlmsg_pid != h->pid || nlmh->nlmsg_seq != h->seq) + continue; + + if (nlmh->nlmsg_type == NLMSG_DONE) + { + /* we found the end, leave the loop. */ + done = true; + break; + } + if (nlmh->nlmsg_type == NLMSG_ERROR) + { + struct nlmsgerr *nlerr = (struct nlmsgerr *) NLMSG_DATA (nlmh); + if (nlmh->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) +{ + /* Don't modify errno. */ + INTERNAL_SYSCALL_DECL (err); + (void) INTERNAL_SYSCALL (close, err, 1, h->fd); +} + + +/* Open a NETLINK socket. */ +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; +} + + +/* We know the number of RTM_NEWLINK entries, so we reserve the first + # of entries for this type. All RTM_NEWADDR entries have an index + pointer to the RTM_NEWLINK entry. To find the entry, create + a table to map kernel index entries to our index numbers. + Since we get at first all RTM_NEWLINK entries, it can never happen + that a RTM_NEWADDR index is not known to this map. */ +static int +map_newlink (int index, int *map, int max) +{ + int i; + + for (i = 0; i < max; i++) + { + if (map[i] == -1) + { + map[i] = index; + return i; + } + else if (map[i] == index) + return i; + } + /* This should never be reached. If this will be reached, we have + very big problem. */ + abort (); +} + + +/* 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) +{ + struct netlink_handle nh = { 0, 0, 0, NULL, NULL }; + struct netlink_res *nlp; + struct ifaddrs_storage *ifas; + unsigned int i, newlink, newaddr, newaddr_idx; + int *map_newlink_data; + size_t ifa_data_size = 0; /* Size to allocate for all ifa_data. */ + char *ifa_data_ptr; /* Pointer to the unused part of memory for + ifa_data. */ + + if (ifap) + *ifap = NULL; + + if (netlink_open (&nh) < 0) + { +#if __ASSUME_NETLINK_SUPPORT == 0 + no_netlink_support = 1; +#else + return -1; +#endif + } + +#if __ASSUME_NETLINK_SUPPORT == 0 + if (no_netlink_support) + return fallback_getifaddrs (ifap); +#endif + + nh.pid = getpid (); + + /* Tell the kernel that we wish to get a list of all + active interfaces. */ + if (netlink_sendreq (&nh, RTM_GETLINK) < 0) + { + netlink_close (&nh); + return -1; + } + /* Collect all data for every interface. */ + if (netlink_receive (&nh) < 0) + { + free_netlink_handle (&nh); + netlink_close (&nh); + return -1; + } + + + /* Now ask the kernel for all addresses which are assigned + to an interface. Since we store the addresses after the + interfaces in the list, we will later always find the + interface before the corresponding addresses. */ + ++nh.seq; + if (netlink_sendreq (&nh, RTM_GETADDR) < 0) + { + free_netlink_handle (&nh); + netlink_close (&nh); + return -1; + } + /* Collect all data for every inerface. */ + if (netlink_receive (&nh) < 0) + { + free_netlink_handle (&nh); + netlink_close (&nh); + return -1; + } + + /* Count all RTM_NEWLINK and RTM_NEWADDR 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; + + /* Walk through all entries we got from the kernel and look, which + message type they contain. */ + 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) + { + /* A RTM_NEWLINK message can have IFLA_STATS data. We need to + know the size before creating the list to allocate enough + memory. */ + struct ifinfomsg *ifim = (struct ifinfomsg *) NLMSG_DATA (nlh); + struct rtattr *rta = IFLA_RTA (ifim); + size_t rtasize = IFLA_PAYLOAD (nlh); + + while (RTA_OK (rta, rtasize)) + { + size_t rta_payload = RTA_PAYLOAD (rta); + + if (rta->rta_type == IFLA_STATS) + { + ifa_data_size += rta_payload; + break; + } + else + rta = RTA_NEXT (rta, rtasize); + } + ++newlink; + } + else if (nlh->nlmsg_type == RTM_NEWADDR) + ++newaddr; + } + } + + /* Return if no interface is up. */ + if ((newlink + newaddr) == 0) + { + free_netlink_handle (&nh); + netlink_close (&nh); + return 0; + } + + /* Table for mapping kernel index to entry in our list. */ + map_newlink_data = alloca (newlink * sizeof (int)); + + /* Allocate memory for all entries we have and initialize next + pointer. */ + ifas = (struct ifaddrs_storage *) calloc (1, + (newlink + newaddr) + * sizeof (struct ifaddrs_storage) + + ifa_data_size); + if (ifas == NULL) + { + free_netlink_handle (&nh); + netlink_close (&nh); + return -1; + } + + for (i = 0; i < newlink + newaddr - 1; i++) + { + ifas[i].ifa.ifa_next = &ifas[i + 1].ifa; + map_newlink_data[i] = -1; + } + ifa_data_ptr = (char *)&ifas[newlink + newaddr]; + newaddr_idx = 0; /* Counter for newaddr index. */ + + /* Walk through the list of data we got from the kernel. */ + for (nlp = nh.nlm_list; nlp; nlp = nlp->next) + { + struct nlmsghdr *nlh; + size_t size = nlp->size; + + if (nlp->nlh == NULL) + continue; + + /* Walk through one message and look at the type: If it is our + message, we need RTM_NEWLINK/RTM_NEWADDR and stop if we reach + the end or we find the end marker (in this case we ignore the + following data. */ + for (nlh = nlp->nlh; NLMSG_OK (nlh, size); nlh = NLMSG_NEXT (nlh, size)) + { + int 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) + { + /* We found a new interface. Now extract everything from the + interface data we got and need. */ + struct ifinfomsg *ifim = (struct ifinfomsg *) NLMSG_DATA (nlh); + struct rtattr *rta = IFLA_RTA (ifim); + size_t rtasize = IFLA_PAYLOAD (nlh); + + /* interfaces are stored in the first "newlink" entries + of our list, starting in the order as we got from the + kernel. */ + ifa_index = map_newlink (ifim->ifi_index - 1, + map_newlink_data, newlink); + ifas[ifa_index].ifa.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: + ifas[ifa_index].addr.sl.sll_family = AF_PACKET; + memcpy (ifas[ifa_index].addr.sl.sll_addr, + (char *) rta_data, rta_payload); + ifas[ifa_index].addr.sl.sll_halen = rta_payload; + ifas[ifa_index].addr.sl.sll_ifindex = ifim->ifi_index; + ifas[ifa_index].addr.sl.sll_hatype = ifim->ifi_type; + + ifas[ifa_index].ifa.ifa_addr = &ifas[ifa_index].addr.sa; + break; + + case IFLA_BROADCAST: + ifas[ifa_index].broadaddr.sl.sll_family = AF_PACKET; + memcpy (ifas[ifa_index].broadaddr.sl.sll_addr, + (char *) rta_data, rta_payload); + ifas[ifa_index].broadaddr.sl.sll_halen = rta_payload; + ifas[ifa_index].broadaddr.sl.sll_ifindex + = ifim->ifi_index; + ifas[ifa_index].broadaddr.sl.sll_hatype = ifim->ifi_type; + + ifas[ifa_index].ifa.ifa_broadaddr + = &ifas[ifa_index].broadaddr.sa; + break; + + case IFLA_IFNAME: /* Name of Interface */ + if ((rta_payload + 1) <= sizeof (ifas[ifa_index].name)) + { + ifas[ifa_index].ifa.ifa_name = ifas[ifa_index].name; + strncpy (ifas[ifa_index].name, rta_data, + rta_payload); + ifas[ifa_index].name[rta_payload] = '\0'; + } + break; + + case IFLA_STATS: /* Statistics of Interface */ + ifas[ifa_index].ifa.ifa_data = ifa_data_ptr; + ifa_data_ptr += rta_payload; + memcpy (ifas[ifa_index].ifa.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); + + /* New Addresses are stored in the order we got them from + the kernel after interfaces. Theoretical it is possible + that we have holes in the interface part of the list, + but we always have already the interface for this address. */ + ifa_index = newlink + newaddr_idx; + ifas[ifa_index].ifa.ifa_flags + = ifas[map_newlink (ifam->ifa_index - 1, + map_newlink_data, newlink)].ifa.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; + + if (ifas[ifa_index].ifa.ifa_addr != NULL) + { + /* In a point-to-poing network IFA_ADDRESS + contains the destination address, local + address is supplied in IFA_LOCAL attribute. + destination address and broadcast address + are stored in an union, so it doesn't matter + which name we use. */ + ifas[ifa_index].ifa.ifa_broadaddr + = &ifas[ifa_index].broadaddr.sa; + sa = &ifas[ifa_index].broadaddr.sa; + } + else + { + ifas[ifa_index].ifa.ifa_addr + = &ifas[ifa_index].addr.sa; + sa = &ifas[ifa_index].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: + if (ifas[ifa_index].ifa.ifa_addr != NULL) + { + /* If ifa_addr is set and we get IFA_LOCAL, + assume we have a point-to-point network. + Move address to correct field. */ + ifas[ifa_index].broadaddr = ifas[ifa_index].addr; + ifas[ifa_index].ifa.ifa_broadaddr + = &ifas[ifa_index].broadaddr.sa; + memset (&ifas[ifa_index].addr, '\0', + sizeof (ifas[ifa_index].addr)); + } + + ifas[ifa_index].ifa.ifa_addr = &ifas[ifa_index].addr.sa; + ifas[ifa_index].ifa.ifa_addr->sa_family + = ifam->ifa_family; + + switch (ifam->ifa_family) + { + case AF_INET: + memcpy (&ifas[ifa_index].addr.s4.sin_addr, + rta_data, rta_payload); + break; + + case AF_INET6: + memcpy (&ifas[ifa_index].addr.s6.sin6_addr, + rta_data, rta_payload); + if (IN6_IS_ADDR_LINKLOCAL (rta_data) || + IN6_IS_ADDR_MC_LINKLOCAL (rta_data)) + ifas[ifa_index].addr.s6.sin6_scope_id = + ifam->ifa_scope; + break; + + default: + memcpy (ifas[ifa_index].addr.sa.sa_data, + rta_data, rta_payload); + break; + } + break; + + case IFA_BROADCAST: + /* We get IFA_BROADCAST, so IFA_LOCAL was too much. */ + if (ifas[ifa_index].ifa.ifa_broadaddr != NULL) + memset (&ifas[ifa_index].broadaddr, '\0', + sizeof (ifas[ifa_index].broadaddr)); + + ifas[ifa_index].ifa.ifa_broadaddr + = &ifas[ifa_index].broadaddr.sa; + ifas[ifa_index].ifa.ifa_broadaddr->sa_family + = ifam->ifa_family; + + switch (ifam->ifa_family) + { + case AF_INET: + memcpy (&ifas[ifa_index].broadaddr.s4.sin_addr, + rta_data, rta_payload); + break; + + case AF_INET6: + memcpy (&ifas[ifa_index].broadaddr.s6.sin6_addr, + rta_data, rta_payload); + if (IN6_IS_ADDR_LINKLOCAL (rta_data) || + IN6_IS_ADDR_MC_LINKLOCAL (rta_data)) + ifas[ifa_index].broadaddr.s6.sin6_scope_id = + ifam->ifa_scope; + break; + + default: + memcpy (&ifas[ifa_index].broadaddr.sa.sa_data, + rta_data, rta_payload); + break; + } + break; + + case IFA_LABEL: + if (rta_payload + 1 <= sizeof (ifas[ifa_index].name)) + { + ifas[ifa_index].ifa.ifa_name = ifas[ifa_index].name; + strncpy (ifas[ifa_index].name, rta_data, + rta_payload); + ifas[ifa_index].name[rta_payload] = '\0'; + } + else + abort (); + break; + + case IFA_UNSPEC: + break; + case IFA_CACHEINFO: + break; + default: + break; + } + + rta = RTA_NEXT (rta, rtasize); + } + + /* If we didn't get the interface name with the + address, use the name from the interface entry. */ + if (ifas[ifa_index].ifa.ifa_name == NULL) + ifas[ifa_index].ifa.ifa_name + = ifas[map_newlink (ifam->ifa_index - 1, + map_newlink_data, newlink)].ifa.ifa_name; + + /* Calculate the netmask. */ + if (ifas[ifa_index].ifa.ifa_addr + && ifas[ifa_index].ifa.ifa_addr->sa_family != AF_UNSPEC + && ifas[ifa_index].ifa.ifa_addr->sa_family != AF_PACKET) + { + uint32_t max_prefixlen = 0; + char *cp = NULL; + + ifas[ifa_index].ifa.ifa_netmask + = &ifas[ifa_index].netmask.sa; + + switch (ifas[ifa_index].ifa.ifa_addr->sa_family) + { + case AF_INET: + cp = (char *) &ifas[ifa_index].netmask.s4.sin_addr; + max_prefixlen = 32; + break; + + case AF_INET6: + cp = (char *) &ifas[ifa_index].netmask.s6.sin6_addr; + max_prefixlen = 128; + break; + } + + ifas[ifa_index].ifa.ifa_netmask->sa_family + = ifas[ifa_index].ifa.ifa_addr->sa_family; + + if (cp != NULL) + { + 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[0].ifa; + + return 0; +} + + +#if __ASSUME_NETLINK_SUPPORT != 0 +void +freeifaddrs (struct ifaddrs *ifa) +{ + free (ifa); +} +#endif diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h index 9909b75393..b016b6c077 100644 --- a/sysdeps/unix/sysv/linux/kernel-features.h +++ b/sysdeps/unix/sysv/linux/kernel-features.h @@ -279,3 +279,9 @@ && (defined __ia64__ || defined __s390__ || defined __powerpc__) # define __ASSUME_CLONE_THREAD_FLAGS 1 #endif + +/* With kernel 2.4.17 we always have netlink support. */ +#if __LINUX_KERNEL_VERSION >= (132096+17) +# define __ASSUME_NETLINK_SUPPORT 1 +#endif + |