diff options
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/udp.c | 84 | ||||
| -rw-r--r-- | net/ipv4/udp_impl.h | 2 | ||||
| -rw-r--r-- | net/ipv4/udplite.c | 3 |
3 files changed, 47 insertions, 42 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 69d4bd1..a581b54 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -113,9 +113,8 @@ DEFINE_SNMP_STAT(struct udp_mib, udp_statistics) __read_mostly; struct hlist_head udp_hash[UDP_HTABLE_SIZE]; DEFINE_RWLOCK(udp_hash_lock); -static int udp_port_rover; - -static inline int __udp_lib_lport_inuse(__u16 num, struct hlist_head udptable[]) +static inline int __udp_lib_lport_inuse(__u16 num, + const struct hlist_head udptable[]) { struct sock *sk; struct hlist_node *node; @@ -132,11 +131,10 @@ static inline int __udp_lib_lport_inuse(__u16 num, struct hlist_head udptable[]) * @sk: socket struct in question * @snum: port number to look up * @udptable: hash list table, must be of UDP_HTABLE_SIZE - * @port_rover: pointer to record of last unallocated port * @saddr_comp: AF-dependent comparison of bound local IP addresses */ int __udp_lib_get_port(struct sock *sk, unsigned short snum, - struct hlist_head udptable[], int *port_rover, + struct hlist_head udptable[], int (*saddr_comp)(const struct sock *sk1, const struct sock *sk2 ) ) { @@ -146,49 +144,56 @@ int __udp_lib_get_port(struct sock *sk, unsigned short snum, int error = 1; write_lock_bh(&udp_hash_lock); - if (snum == 0) { - int best_size_so_far, best, result, i; - - if (*port_rover > sysctl_local_port_range[1] || - *port_rover < sysctl_local_port_range[0]) - *port_rover = sysctl_local_port_range[0]; - best_size_so_far = 32767; - best = result = *port_rover; - for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) { - int size; - - head = &udptable[result & (UDP_HTABLE_SIZE - 1)]; - if (hlist_empty(head)) { - if (result > sysctl_local_port_range[1]) - result = sysctl_local_port_range[0] + - ((result - sysctl_local_port_range[0]) & - (UDP_HTABLE_SIZE - 1)); + + if (!snum) { + int i; + int low = sysctl_local_port_range[0]; + int high = sysctl_local_port_range[1]; + unsigned rover, best, best_size_so_far; + + best_size_so_far = UINT_MAX; + best = rover = net_random() % (high - low) + low; + + /* 1st pass: look for empty (or shortest) hash chain */ + for (i = 0; i < UDP_HTABLE_SIZE; i++) { + int size = 0; + + head = &udptable[rover & (UDP_HTABLE_SIZE - 1)]; + if (hlist_empty(head)) goto gotit; - } - size = 0; + sk_for_each(sk2, node, head) { if (++size >= best_size_so_far) goto next; } best_size_so_far = size; - best = result; + best = rover; next: - ; + /* fold back if end of range */ + if (++rover > high) + rover = low + ((rover - low) + & (UDP_HTABLE_SIZE - 1)); + + } - result = best; - for (i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; - i++, result += UDP_HTABLE_SIZE) { - if (result > sysctl_local_port_range[1]) - result = sysctl_local_port_range[0] - + ((result - sysctl_local_port_range[0]) & - (UDP_HTABLE_SIZE - 1)); - if (! __udp_lib_lport_inuse(result, udptable)) - break; + + /* 2nd pass: find hole in shortest hash chain */ + rover = best; + for (i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++) { + if (! __udp_lib_lport_inuse(rover, udptable)) + goto gotit; + rover += UDP_HTABLE_SIZE; + if (rover > high) + rover = low + ((rover - low) + & (UDP_HTABLE_SIZE - 1)); } - if (i >= (1 << 16) / UDP_HTABLE_SIZE) - goto fail; + + + /* All ports in use! */ + goto fail; + gotit: - *port_rover = snum = result; + snum = rover; } else { head = &udptable[snum & (UDP_HTABLE_SIZE - 1)]; @@ -201,6 +206,7 @@ gotit: (*saddr_comp)(sk, sk2) ) goto fail; } + inet_sk(sk)->num = snum; sk->sk_hash = snum; if (sk_unhashed(sk)) { @@ -217,7 +223,7 @@ fail: int udp_get_port(struct sock *sk, unsigned short snum, int (*scmp)(const struct sock *, const struct sock *)) { - return __udp_lib_get_port(sk, snum, udp_hash, &udp_port_rover, scmp); + return __udp_lib_get_port(sk, snum, udp_hash, scmp); } int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2) diff --git a/net/ipv4/udp_impl.h b/net/ipv4/udp_impl.h index 820a477..6c55828 100644 --- a/net/ipv4/udp_impl.h +++ b/net/ipv4/udp_impl.h @@ -9,7 +9,7 @@ extern int __udp4_lib_rcv(struct sk_buff *, struct hlist_head [], int ); extern void __udp4_lib_err(struct sk_buff *, u32, struct hlist_head []); extern int __udp_lib_get_port(struct sock *sk, unsigned short snum, - struct hlist_head udptable[], int *port_rover, + struct hlist_head udptable[], int (*)(const struct sock*,const struct sock*)); extern int ipv4_rcv_saddr_equal(const struct sock *, const struct sock *); diff --git a/net/ipv4/udplite.c b/net/ipv4/udplite.c index f34fd68..9497720 100644 --- a/net/ipv4/udplite.c +++ b/net/ipv4/udplite.c @@ -16,12 +16,11 @@ DEFINE_SNMP_STAT(struct udp_mib, udplite_statistics) __read_mostly; struct hlist_head udplite_hash[UDP_HTABLE_SIZE]; -static int udplite_port_rover; int udplite_get_port(struct sock *sk, unsigned short p, int (*c)(const struct sock *, const struct sock *)) { - return __udp_lib_get_port(sk, p, udplite_hash, &udplite_port_rover, c); + return __udp_lib_get_port(sk, p, udplite_hash, c); } static int udplite_v4_get_port(struct sock *sk, unsigned short snum) |