[PATCH v2] remove automatic port id generation
Julien Courtat
julien.courtat at 6wind.com
Wed Jun 17 06:49:55 PDT 2015
Since kernel can automatically set a unique portid to each socket any
application would bind with, there is no use to keep the portid generation
procedure made of 22 bits for the pid and 10 bits left for a pseudo
random value.
Remove this procedure and let kernel choose a port id for the socket.
It is still possible for an application to set the port id manually via
nl_socket_set_local_port().
Signed-off-by: Julien Courtat <julien.courtat at 6wind.com>
---
lib/nl.c | 47 +++---------------
lib/socket.c | 153 ----------------------------------------------------------
2 files changed, 7 insertions(+), 193 deletions(-)
diff --git a/lib/nl.c b/lib/nl.c
index 8fc9ec1..d0828fc 100644
--- a/lib/nl.c
+++ b/lib/nl.c
@@ -126,47 +126,14 @@ int nl_connect(struct nl_sock *sk, int protocol)
if (err < 0)
goto errout;
- if (_nl_socket_is_local_port_unspecified (sk)) {
- uint32_t port;
- uint32_t used_ports[32] = { 0 };
-
- while (1) {
- port = _nl_socket_generate_local_port_no_release(sk);
-
- if (port == UINT32_MAX) {
- NL_DBG(4, "nl_connect(%p): no more unused local ports.\n", sk);
- _nl_socket_used_ports_release_all(used_ports);
- err = -NLE_EXIST;
- goto errout;
- }
- err = bind(sk->s_fd, (struct sockaddr*) &sk->s_local,
- sizeof(sk->s_local));
- if (err == 0)
- break;
-
- errsv = errno;
- if (errsv == EADDRINUSE) {
- NL_DBG(4, "nl_connect(%p): local port %u already in use. Retry.\n", sk, (unsigned) port);
- _nl_socket_used_ports_set(used_ports, port);
- } else {
- NL_DBG(4, "nl_connect(%p): bind() for port %u failed with %d (%s)\n",
- sk, (unsigned) port, errsv, strerror_r(errsv, buf, sizeof(buf)));
- _nl_socket_used_ports_release_all(used_ports);
- err = -nl_syserr2nlerr(errsv);
- goto errout;
- }
- }
- _nl_socket_used_ports_release_all(used_ports);
- } else {
- err = bind(sk->s_fd, (struct sockaddr*) &sk->s_local,
- sizeof(sk->s_local));
- if (err != 0) {
- errsv = errno;
- NL_DBG(4, "nl_connect(%p): bind() failed with %d (%s)\n",
+ err = bind(sk->s_fd, (struct sockaddr*) &sk->s_local,
+ sizeof(sk->s_local));
+ if (err != 0) {
+ errsv = errno;
+ NL_DBG(4, "nl_connect(%p): bind() failed with %d (%s)\n",
sk, errsv, strerror_r(errsv, buf, sizeof(buf)));
- err = -nl_syserr2nlerr(errsv);
- goto errout;
- }
+ err = -nl_syserr2nlerr(errsv);
+ goto errout;
}
addrlen = sizeof(local);
diff --git a/lib/socket.c b/lib/socket.c
index b29d1da..8aa909e 100644
--- a/lib/socket.c
+++ b/lib/socket.c
@@ -59,120 +59,6 @@ static void __init init_default_cb(void)
}
}
-static uint32_t used_ports_map[32];
-static NL_RW_LOCK(port_map_lock);
-
-static uint32_t generate_local_port(void)
-{
- int i, j, n, m;
- static uint16_t idx_state = 0;
- uint32_t pid = getpid() & 0x3FFFFF;
-
- nl_write_lock(&port_map_lock);
-
- if (idx_state == 0) {
- uint32_t t = time(NULL);
-
- /* from time to time (on average each 2^15 calls), the idx_state will
- * be zero again. No problem, just "seed" anew with time(). */
- idx_state = t ^ (t >> 16) ^ 0x3047;
- } else
- idx_state = idx_state + 20011; /* add prime number */
-
- i = idx_state >> 5;
- n = idx_state;
- for (j = 0; j < 32; j++) {
- /* walk the index somewhat randomized, with always leaving the block
- * #0 as last. The reason is that libnl-1 will start at block #0,
- * so just leave the first 32 ports preferably for libnl-1 owned sockets
- * (this is relevant only if the applications ends up using both versions
- * of the library and doesn't hurt otherwise). */
- if (j == 31)
- i = 0;
- else
- i = (((i-1) + 7) % 31) + 1;
-
- if (used_ports_map[i] == 0xFFFFFFFF)
- continue;
-
- for (m = 0; m < 32; m++) {
- n = (n + 13) % 32;
- if (1UL & (used_ports_map[i] >> n))
- continue;
-
- used_ports_map[i] |= (1UL << n);
- n += (i * 32);
-
- /* PID_MAX_LIMIT is currently at 2^22, leaving 10 bit
- * to, i.e. 1024 unique ports per application. */
-
- nl_write_unlock(&port_map_lock);
-
- return pid + (((uint32_t)n) << 22);
- }
- }
-
- nl_write_unlock(&port_map_lock);
-
- /* Out of sockets in our own PID namespace, what to do? FIXME */
- NL_DBG(1, "Warning: Ran out of unique local port namespace\n");
- return UINT32_MAX;
-}
-
-static void release_local_port(uint32_t port)
-{
- int nr;
- uint32_t mask;
-
- if (port == UINT32_MAX)
- return;
-
- BUG_ON(port == 0);
-
- nr = port >> 22;
- mask = 1UL << (nr % 32);
- nr /= 32;
-
- nl_write_lock(&port_map_lock);
- BUG_ON((used_ports_map[nr] & mask) != mask);
- used_ports_map[nr] &= ~mask;
- nl_write_unlock(&port_map_lock);
-}
-
-/** \cond skip */
-void _nl_socket_used_ports_release_all(const uint32_t *used_ports)
-{
- int i;
-
- for (i = 0; i < 32; i++) {
- if (used_ports[i] != 0) {
- nl_write_lock(&port_map_lock);
- for (; i < 32; i++) {
- BUG_ON((used_ports_map[i] & used_ports[i]) != used_ports[i]);
- used_ports_map[i] &= ~(used_ports[i]);
- }
- nl_write_unlock(&port_map_lock);
- return;
- }
- }
-}
-
-void _nl_socket_used_ports_set(uint32_t *used_ports, uint32_t port)
-{
- int nr;
- int32_t mask;
-
- nr = port >> 22;
- mask = 1UL << (nr % 32);
- nr /= 32;
-
- /*
- BUG_ON(port == UINT32_MAX || port == 0 || (getpid() & 0x3FFFFF) != (port & 0x3FFFFF));
- BUG_ON(used_ports[nr] & mask);
- */
-
- used_ports[nr] |= mask;
-}
/** \endcond */
/**
@@ -251,9 +137,6 @@ void nl_socket_free(struct nl_sock *sk)
if (sk->s_fd >= 0)
close(sk->s_fd);
- if (!(sk->s_flags & NL_OWN_PORT))
- release_local_port(sk->s_local.nl_pid);
-
nl_cb_put(sk->s_cb);
free(sk);
}
@@ -329,28 +212,6 @@ void nl_socket_enable_auto_ack(struct nl_sock *sk)
sk->s_flags &= ~NL_NO_AUTO_ACK;
}
-/** @} */
-
-/** \cond skip */
-int _nl_socket_is_local_port_unspecified(struct nl_sock *sk)
-{
- return (sk->s_local.nl_pid == 0);
-}
-
-uint32_t _nl_socket_generate_local_port_no_release(struct nl_sock *sk)
-{
- uint32_t port;
-
- /* reset the port to generate_local_port(), but do not release
- * the previously generated port. */
-
- port = generate_local_port();
- sk->s_flags &= ~NL_OWN_PORT;
- sk->s_local.nl_pid = port;
- return port;
-}
-/** \endcond */
-
/**
* @name Source Idenficiation
* @{
@@ -358,18 +219,6 @@ uint32_t _nl_socket_generate_local_port_no_release(struct nl_sock *sk)
uint32_t nl_socket_get_local_port(const struct nl_sock *sk)
{
- if (sk->s_local.nl_pid == 0) {
- /* modify the const argument sk. This is justified, because
- * nobody ever saw the local_port from externally. So, we
- * initilize it on first use.
- *
- * Note that this also means that you cannot call this function
- * from multiple threads without synchronization. But nl_sock
- * is not automatically threadsafe anyway, so the user is not
- * allowed to do that.
- */
- return _nl_socket_generate_local_port_no_release((struct nl_sock *) sk);
- }
return sk->s_local.nl_pid;
}
@@ -387,8 +236,6 @@ uint32_t nl_socket_get_local_port(const struct nl_sock *sk)
*/
void nl_socket_set_local_port(struct nl_sock *sk, uint32_t port)
{
- if (!(sk->s_flags & NL_OWN_PORT))
- release_local_port(sk->s_local.nl_pid);
sk->s_flags |= NL_OWN_PORT;
sk->s_local.nl_pid = port;
}
--
1.7.10.4
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