diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/ifaddrs.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/ifaddrs.c | 138 |
1 files changed, 87 insertions, 51 deletions
diff --git a/sysdeps/unix/sysv/linux/ifaddrs.c b/sysdeps/unix/sysv/linux/ifaddrs.c index 8a052e212d..02e6935538 100644 --- a/sysdeps/unix/sysv/linux/ifaddrs.c +++ b/sysdeps/unix/sysv/linux/ifaddrs.c @@ -1,5 +1,5 @@ /* getifaddrs -- get names and addresses of all network interfaces - Copyright (C) 2003, 2004 Free Software Foundation, Inc. + Copyright (C) 2003, 2004, 2005, 2006, 2007 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 @@ -17,6 +17,7 @@ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ +#include <alloca.h> #include <assert.h> #include <errno.h> #include <ifaddrs.h> @@ -24,6 +25,7 @@ #include <netinet/in.h> #include <netpacket/packet.h> #include <stdbool.h> +#include <stdint.h> #include <stdlib.h> #include <string.h> #include <sys/ioctl.h> @@ -84,13 +86,14 @@ __netlink_free_handle (struct netlink_handle *h) } -int +static int __netlink_sendreq (struct netlink_handle *h, int type) { - struct + struct req { struct nlmsghdr nlh; struct rtgenmsg g; + char pad[0]; } req; struct sockaddr_nl nladdr; @@ -103,6 +106,8 @@ __netlink_sendreq (struct netlink_handle *h, int type) req.nlh.nlmsg_pid = 0; req.nlh.nlmsg_seq = h->seq; req.g.rtgen_family = AF_UNSPEC; + if (sizeof (req) != offsetof (struct req, pad)) + memset (req.pad, '\0', sizeof (req) - offsetof (struct req, pad)); memset (&nladdr, '\0', sizeof (nladdr)); nladdr.nl_family = AF_NETLINK; @@ -114,16 +119,40 @@ __netlink_sendreq (struct netlink_handle *h, int type) int -__netlink_receive (struct netlink_handle *h) +__netlink_request (struct netlink_handle *h, int type) { struct netlink_res *nlm_next; - char buf[4096]; - struct iovec iov = { buf, sizeof (buf) }; struct sockaddr_nl nladdr; struct nlmsghdr *nlmh; - int read_len; + ssize_t read_len; bool done = false; +#ifdef PAGE_SIZE + /* Help the compiler optimize out the malloc call if PAGE_SIZE + is constant and smaller or equal to PTHREAD_STACK_MIN/4. */ + const size_t buf_size = PAGE_SIZE; +#else + const size_t buf_size = __getpagesize (); +#endif + bool use_malloc = false; + char *buf; + + if (__libc_use_alloca (buf_size)) + buf = alloca (buf_size); + else + { + buf = malloc (buf_size); + if (buf != NULL) + use_malloc = true; + else + goto out_fail; + } + + struct iovec iov = { buf, buf_size }; + + if (__netlink_sendreq (h, type) < 0) + goto out_fail; + while (! done) { struct msghdr msg = @@ -136,33 +165,25 @@ __netlink_receive (struct netlink_handle *h) read_len = TEMP_FAILURE_RETRY (__recvmsg (h->fd, &msg, 0)); if (read_len < 0) - return -1; + goto out_fail; - if (msg.msg_flags & MSG_TRUNC) - return -1; + if (nladdr.nl_pid != 0) + continue; - nlm_next = (struct netlink_res *) malloc (sizeof (struct netlink_res) - + read_len); - if (nlm_next == NULL) - return -1; - nlm_next->next = NULL; - nlm_next->nlh = memcpy (nlm_next + 1, buf, read_len); - nlm_next->size = read_len; - nlm_next->seq = h->seq; - if (h->nlm_list == NULL) - h->nlm_list = nlm_next; - else - h->end_ptr->next = nlm_next; - h->end_ptr = nlm_next; + if (__builtin_expect (msg.msg_flags & MSG_TRUNC, 0)) + goto out_fail; + size_t count = 0; + size_t remaining_len = read_len; for (nlmh = (struct nlmsghdr *) buf; - NLMSG_OK (nlmh, (size_t) read_len); - nlmh = (struct nlmsghdr *) NLMSG_NEXT (nlmh, read_len)) + NLMSG_OK (nlmh, remaining_len); + nlmh = (struct nlmsghdr *) NLMSG_NEXT (nlmh, remaining_len)) { - if (nladdr.nl_pid != 0 || (pid_t) nlmh->nlmsg_pid != h->pid + if ((pid_t) nlmh->nlmsg_pid != h->pid || nlmh->nlmsg_seq != h->seq) continue; + ++count; if (nlmh->nlmsg_type == NLMSG_DONE) { /* We found the end, leave the loop. */ @@ -176,11 +197,38 @@ __netlink_receive (struct netlink_handle *h) errno = EIO; else errno = -nlerr->error; - return -1; + goto out_fail; } } + + /* If there was nothing with the expected nlmsg_pid and nlmsg_seq, + there is no point to record it. */ + if (count == 0) + continue; + + nlm_next = (struct netlink_res *) malloc (sizeof (struct netlink_res) + + read_len); + if (nlm_next == NULL) + goto out_fail; + nlm_next->next = NULL; + nlm_next->nlh = memcpy (nlm_next + 1, buf, read_len); + nlm_next->size = read_len; + nlm_next->seq = h->seq; + if (h->nlm_list == NULL) + h->nlm_list = nlm_next; + else + h->end_ptr->next = nlm_next; + h->end_ptr = nlm_next; } + + if (use_malloc) + free (buf); return 0; + +out_fail: + if (use_malloc) + free (buf); + return -1; } @@ -268,12 +316,11 @@ getifaddrs (struct ifaddrs **ifap) 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 + char *ifa_data_ptr; /* Pointer to the unused part of memory for ifa_data. */ int result = 0; - if (ifap) - *ifap = NULL; + *ifap = NULL; if (! __no_netlink_support && __netlink_open (&nh) < 0) { @@ -288,28 +335,20 @@ getifaddrs (struct ifaddrs **ifap) #endif /* Tell the kernel that we wish to get a list of all - active interfaces. */ - if (__netlink_sendreq (&nh, RTM_GETLINK) < 0) - { - result = -1; - goto exit_close; - } - /* Collect all data for every interface. */ - if (__netlink_receive (&nh) < 0) + active interfaces, collect all data for every interface. */ + if (__netlink_request (&nh, RTM_GETLINK) < 0) { result = -1; goto exit_free; } - /* 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. */ + to an interface and collect all data for every 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 - /* Collect all data for every interface. */ - || __netlink_receive (&nh) < 0) + if (__netlink_request (&nh, RTM_GETADDR) < 0) { result = -1; goto exit_free; @@ -327,7 +366,7 @@ getifaddrs (struct ifaddrs **ifap) continue; /* Walk through all entries we got from the kernel and look, which - message type they contain. */ + 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. */ @@ -423,7 +462,7 @@ getifaddrs (struct ifaddrs **ifap) /* 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, ifas, + ifa_index = map_newlink (ifim->ifi_index - 1, ifas, map_newlink_data, newlink); ifas[ifa_index].ifa.ifa_flags = ifim->ifi_flags; @@ -762,13 +801,10 @@ getifaddrs (struct ifaddrs **ifap) memmove (ifas, &ifas[newlink], sizeof (struct ifaddrs_storage)); } - if (ifap != NULL) - *ifap = &ifas[0].ifa; + *ifap = &ifas[0].ifa; exit_free: __netlink_free_handle (&nh); - - exit_close: __netlink_close (&nh); return result; |