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authorOndřej Bílka <neleai@seznam.cz>2015-01-06 17:26:44 +0100
committerOndřej Bílka <neleai@seznam.cz>2015-01-06 17:26:44 +0100
commit4790d9a2c0a04964a5e0caf2af18b813d8fd4008 (patch)
treec1046b5103c551efa0f51343a9236b6f9c23b09d
parent14bb4e57c094849228ad8524693ab9432c38396c (diff)
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Clean up check_pf allocation pattern. addresses
We simplify allocation strategy there so instead of using temporary linked list and then copying entries to output array we keep them in resizable array.
-rw-r--r--sysdeps/unix/sysv/linux/check_pf.c123
1 files changed, 39 insertions, 84 deletions
diff --git a/sysdeps/unix/sysv/linux/check_pf.c b/sysdeps/unix/sysv/linux/check_pf.c
index d7efe72d7f..162606d7ab 100644
--- a/sysdeps/unix/sysv/linux/check_pf.c
+++ b/sysdeps/unix/sysv/linux/check_pf.c
@@ -105,6 +105,11 @@ cache_valid_p (void)
static struct cached_data *
make_request (int fd, pid_t pid)
{
+ struct cached_data *result = NULL;
+
+ size_t result_len = 0;
+ size_t result_cap = 32;
+
struct req
{
struct nlmsghdr nlh;
@@ -130,26 +135,11 @@ make_request (int fd, pid_t pid)
nladdr.nl_family = AF_NETLINK;
#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 ();
+ const size_t buf_size = 4096;
#endif
- bool use_malloc = false;
- char *buf;
- size_t alloca_used = 0;
-
- if (__libc_use_alloca (buf_size))
- buf = alloca_account (buf_size, alloca_used);
- else
- {
- buf = malloc (buf_size);
- if (buf != NULL)
- use_malloc = true;
- else
- goto out_fail;
- }
+ char buf[buf_size];
struct iovec iov = { buf, buf_size };
@@ -159,13 +149,7 @@ make_request (int fd, pid_t pid)
goto out_fail;
bool done = false;
- struct in6ailist
- {
- struct in6addrinfo info;
- struct in6ailist *next;
- bool use_malloc;
- } *in6ailist = NULL;
- size_t in6ailistlen = 0;
+
bool seen_ipv4 = false;
bool seen_ipv6 = false;
@@ -181,10 +165,10 @@ make_request (int fd, pid_t pid)
ssize_t read_len = TEMP_FAILURE_RETRY (__recvmsg (fd, &msg, 0));
if (read_len <= 0)
- goto out_fail2;
+ goto out_fail;
if (msg.msg_flags & MSG_TRUNC)
- goto out_fail2;
+ goto out_fail;
struct nlmsghdr *nlmh;
for (nlmh = (struct nlmsghdr *) buf;
@@ -240,40 +224,35 @@ make_request (int fd, pid_t pid)
}
}
- struct in6ailist *newp;
- if (__libc_use_alloca (alloca_used + sizeof (*newp)))
+ if (result_len == 0 || result_len == result_cap)
{
- newp = alloca_account (sizeof (*newp), alloca_used);
- newp->use_malloc = false;
+ result_cap = 2 * result_cap;
+ result = realloc (result, sizeof (*result)
+ + result_cap
+ * sizeof (struct in6addrinfo));
}
- else
- {
- newp = malloc (sizeof (*newp));
- if (newp == NULL)
- goto out_fail2;
- newp->use_malloc = true;
- }
- newp->info.flags = (((ifam->ifa_flags
- & (IFA_F_DEPRECATED
- | IFA_F_OPTIMISTIC))
- ? in6ai_deprecated : 0)
- | ((ifam->ifa_flags
- & IFA_F_HOMEADDRESS)
- ? in6ai_homeaddress : 0));
- newp->info.prefixlen = ifam->ifa_prefixlen;
- newp->info.index = ifam->ifa_index;
+
+ if (!result)
+ goto out_fail;
+
+ struct in6addrinfo *info = &result->in6ai[result_len++];
+
+ info->flags = (((ifam->ifa_flags
+ & (IFA_F_DEPRECATED | IFA_F_OPTIMISTIC))
+ ? in6ai_deprecated : 0)
+ | ((ifam->ifa_flags & IFA_F_HOMEADDRESS)
+ ? in6ai_homeaddress : 0));
+ info->prefixlen = ifam->ifa_prefixlen;
+ info->index = ifam->ifa_index;
if (ifam->ifa_family == AF_INET)
{
- newp->info.addr[0] = 0;
- newp->info.addr[1] = 0;
- newp->info.addr[2] = htonl (0xffff);
- newp->info.addr[3] = *(const in_addr_t *) address;
+ info->addr[0] = 0;
+ info->addr[1] = 0;
+ info->addr[2] = htonl (0xffff);
+ info->addr[3] = *(const in_addr_t *) address;
}
else
- memcpy (newp->info.addr, address, sizeof (newp->info.addr));
- newp->next = in6ailist;
- in6ailist = newp;
- ++in6ailistlen;
+ memcpy (info->addr, address, sizeof (info->addr));
}
else if (nlmh->nlmsg_type == NLMSG_DONE)
/* We found the end, leave the loop. */
@@ -282,53 +261,29 @@ make_request (int fd, pid_t pid)
}
while (! done);
- struct cached_data *result;
- if (seen_ipv6 && in6ailist != NULL)
+ if (seen_ipv6 && result != NULL)
{
- result = malloc (sizeof (*result)
- + in6ailistlen * sizeof (struct in6addrinfo));
- if (result == NULL)
- goto out_fail2;
-
result->timestamp = get_nl_timestamp ();
result->usecnt = 2;
result->seen_ipv4 = seen_ipv4;
result->seen_ipv6 = true;
- result->in6ailen = in6ailistlen;
-
- do
- {
- result->in6ai[--in6ailistlen] = in6ailist->info;
- struct in6ailist *next = in6ailist->next;
- if (in6ailist->use_malloc)
- free (in6ailist);
- in6ailist = next;
- }
- while (in6ailist != NULL);
+ result->in6ailen = result_len;
}
else
{
+ free (result);
+
atomic_add (&noai6ai_cached.usecnt, 2);
noai6ai_cached.seen_ipv4 = seen_ipv4;
noai6ai_cached.seen_ipv6 = seen_ipv6;
result = &noai6ai_cached;
}
- if (use_malloc)
- free (buf);
return result;
- out_fail2:
- while (in6ailist != NULL)
- {
- struct in6ailist *next = in6ailist->next;
- if (in6ailist->use_malloc)
- free (in6ailist);
- in6ailist = next;
- }
out_fail:
- if (use_malloc)
- free (buf);
+
+ free (result);
return NULL;
}