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Diffstat (limited to 'sysdeps/unix/sysv/linux/ifaddrs.c')
-rw-r--r--sysdeps/unix/sysv/linux/ifaddrs.c138
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;
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-16 06:32:23 +0000