diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/check_pf.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/check_pf.c | 175 |
1 files changed, 143 insertions, 32 deletions
diff --git a/sysdeps/unix/sysv/linux/check_pf.c b/sysdeps/unix/sysv/linux/check_pf.c index d5ad7ea2e5..1f66684e4f 100644 --- a/sysdeps/unix/sysv/linux/check_pf.c +++ b/sysdeps/unix/sysv/linux/check_pf.c @@ -1,5 +1,5 @@ /* Determine protocol families for which interfaces exist. Linux version. - Copyright (C) 2003, 2006, 2007, 2008, 2010, 2011 Free Software Foundation, Inc. + Copyright (C) 2003, 2006-2008, 2010, 2011 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 @@ -33,6 +33,9 @@ #include <not-cancel.h> #include <kernel-features.h> +#include <bits/libc-lock.h> +#include <atomic.h> +#include <nscd/nscd-client.h> #ifndef IFA_F_HOMEADDRESS @@ -43,9 +46,42 @@ #endif -static int -make_request (int fd, pid_t pid, bool *seen_ipv4, bool *seen_ipv6, - struct in6addrinfo **in6ai, size_t *in6ailen) +struct cached_data +{ + uint32_t timestamp; + uint32_t usecnt; + bool seen_ipv4; + bool seen_ipv6; + size_t in6ailen; + struct in6addrinfo in6ai[0]; +}; + +static struct cached_data noai6ai_cached = + { + .usecnt = 3, /* Make sure we never try to delete this entry. */ + .in6ailen = 0 + }; + +static struct cached_data *cache; +__libc_lock_define_initialized (static, lock); + + +#ifdef IS_IN_nscd +static uint32_t nl_timestamp; + +uint32_t +__bump_nl_timestamp (void) +{ + if (atomic_increment_val (&nl_timestamp) == 0) + atomic_increment (&nl_timestamp); + + return nl_timestamp; +} +#endif + + +static struct cached_data * +make_request (int fd, pid_t pid) { struct req { @@ -99,9 +135,6 @@ make_request (int fd, pid_t pid, bool *seen_ipv4, bool *seen_ipv6, sizeof (nladdr))) < 0) goto out_fail; - *seen_ipv4 = false; - *seen_ipv6 = false; - bool done = false; struct in6ailist { @@ -109,6 +142,8 @@ make_request (int fd, pid_t pid, bool *seen_ipv4, bool *seen_ipv6, struct in6ailist *next; } *in6ailist = NULL; size_t in6ailistlen = 0; + bool seen_ipv4 = false; + bool seen_ipv6 = false; do { @@ -172,12 +207,12 @@ make_request (int fd, pid_t pid, bool *seen_ipv4, bool *seen_ipv6, { if (*(const in_addr_t *) address != htonl (INADDR_LOOPBACK)) - *seen_ipv4 = true; + seen_ipv4 = true; } else { if (!IN6_IS_ADDR_LOOPBACK (address)) - *seen_ipv6 = true; + seen_ipv6 = true; } } @@ -211,30 +246,46 @@ make_request (int fd, pid_t pid, bool *seen_ipv4, bool *seen_ipv6, } while (! done); - if (*seen_ipv6 && in6ailist != NULL) + struct cached_data *result; + if (seen_ipv6 && in6ailist != NULL) { - *in6ai = malloc (in6ailistlen * sizeof (**in6ai)); - if (*in6ai == NULL) + result = malloc (sizeof (*result) + + in6ailistlen * sizeof (struct in6addrinfo)); + if (result == NULL) goto out_fail; - *in6ailen = in6ailistlen; +#ifdef IS_IN_nscd + result->timestamp = nl_timestamp; +#else + result->timestamp = __nscd_get_nl_timestamp (); +#endif + result->usecnt = 2; + result->seen_ipv4 = seen_ipv4; + result->seen_ipv6 = true; + result->in6ailen = in6ailistlen; do { - (*in6ai)[--in6ailistlen] = in6ailist->info; + result->in6ai[--in6ailistlen] = in6ailist->info; in6ailist = in6ailist->next; } while (in6ailist != NULL); } + else + { + noai6ai_cached.seen_ipv4 = seen_ipv4; + noai6ai_cached.seen_ipv6 = seen_ipv6; + result = &noai6ai_cached; + } if (use_malloc) free (buf); - return 0; + return result; out_fail: if (use_malloc) free (buf); - return -1; + return NULL; } @@ -258,28 +309,65 @@ __check_pf (bool *seen_ipv4, bool *seen_ipv6, if (! __no_netlink_support) { - int fd = __socket (PF_NETLINK, SOCK_RAW, NETLINK_ROUTE); + struct cached_data *olddata = NULL; + struct cached_data *data = NULL; - if (__builtin_expect (fd >= 0, 1)) + __libc_lock_lock (lock); + +#ifdef IS_IN_nscd +# define cache_valid() nl_timestamp != 0 && cache->timestamp == nl_timestamp +#else +# define cache_valid() \ + ({ uint32_t val = __nscd_get_nl_timestamp (); \ + val != 0 && cache->timestamp == val; }) +#endif + if (cache != NULL && cache_valid ()) + { + data = cache; + atomic_increment (&cache->usecnt); + } + else { - struct sockaddr_nl nladdr; - memset (&nladdr, '\0', sizeof (nladdr)); - nladdr.nl_family = AF_NETLINK; + int fd = __socket (PF_NETLINK, SOCK_RAW, NETLINK_ROUTE); - socklen_t addr_len = sizeof (nladdr); + if (__builtin_expect (fd >= 0, 1)) + { + struct sockaddr_nl nladdr; + memset (&nladdr, '\0', sizeof (nladdr)); + nladdr.nl_family = AF_NETLINK; + + socklen_t addr_len = sizeof (nladdr); + + if(__bind (fd, (struct sockaddr *) &nladdr, sizeof (nladdr)) == 0 + && __getsockname (fd, (struct sockaddr *) &nladdr, + &addr_len) == 0) + data = make_request (fd, nladdr.nl_pid); + + close_not_cancel_no_status (fd); + } + + if (data != NULL) + { + olddata = cache; + cache = data; + } + } - bool success - = (__bind (fd, (struct sockaddr *) &nladdr, sizeof (nladdr)) == 0 - && __getsockname (fd, (struct sockaddr *) &nladdr, - &addr_len) == 0 - && make_request (fd, nladdr.nl_pid, seen_ipv4, seen_ipv6, - in6ai, in6ailen) == 0); + __libc_lock_unlock (lock); - close_not_cancel_no_status (fd); + if (data != NULL) + { + /* It worked. */ + *seen_ipv4 = data->seen_ipv4; + *seen_ipv6 = data->seen_ipv6; + *in6ailen = data->in6ailen; + *in6ai = data->in6ai; + + if (olddata != NULL && olddata->usecnt > 0 + && atomic_add_zero (&olddata->usecnt, -1)) + free (olddata); - if (success) - /* It worked. */ - return; + return; } #if __ASSUME_NETLINK_SUPPORT == 0 @@ -318,3 +406,26 @@ __check_pf (bool *seen_ipv4, bool *seen_ipv6, (void) freeifaddrs (ifa); #endif } + + +void +__free_in6ai (struct in6addrinfo *ai) +{ + if (ai != NULL) + { + struct cached_data *data = + (struct cached_data *) ((char *) ai + - offsetof (struct cached_data, in6ai)); + + if (atomic_add_zero (&data->usecnt, -1)) + { + __libc_lock_lock (lock); + + if (data->usecnt == 0) + /* Still unused. */ + free (data); + + __libc_lock_unlock (lock); + } + } +} |