Commit 38a608c5 authored by Martin Mareš's avatar Martin Mareš

Rewritten the I/O loop. All socket operations are now safe, meaning that

you can delete the socket from anywhere in the hooks and nothing should break.
Also, the receive/transmit buffers are now regular xmalloc()'ed buffers,
not separate resources which would need shuffling around between pools.

sk_close() is gone, use rfree() instead.
parent 206f59df
/*
* BIRD Socket Interface
*
* (c) 1998--1999 Martin Mares <mj@ucw.cz>
* (c) 1998--2004 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
......@@ -13,7 +13,7 @@
typedef struct birdsock {
resource r;
pool *pool; /* Pool for socket data */
pool *pool; /* Pool where incoming connections should be allocated (for SK_xxx_PASSIVE) */
int type; /* Socket type */
void *data; /* User data */
ip_addr saddr, daddr; /* IPA_NONE = unspecified */
......@@ -38,12 +38,11 @@ typedef struct birdsock {
int fd; /* System-dependent data */
node n;
int entered;
void *rbuf_alloc, *tbuf_alloc;
} sock;
sock *sk_new(pool *); /* Allocate new socket */
int sk_open(sock *); /* Open socket */
void sk_close(sock *); /* Safe close of socket even from socket hook */
int sk_send(sock *, unsigned len); /* Send data, <0=err, >0=ok, 0=sleep */
int sk_send_to(sock *, unsigned len, ip_addr to, unsigned port); /* sk_send to given destination */
void sk_dump_all(void);
......@@ -68,7 +67,6 @@ sk_send_buffer_empty(sock *sk)
#define SK_MAGIC 7 /* Internal use by sysdep code */
#define SK_UNIX_PASSIVE 8
#define SK_UNIX 9
#define SK_DELETED 10 /* Internal use by sk_close */
/*
* Multicast sockets are slightly different from the other ones:
......
......@@ -139,7 +139,7 @@ bgp_close_conn(struct bgp_conn *conn)
conn->keepalive_timer = NULL;
rfree(conn->hold_timer);
conn->hold_timer = NULL;
sk_close(conn->sk);
rfree(conn->sk);
conn->sk = NULL;
conn->state = BS_IDLE;
if (conn->error_flag > 1)
......@@ -235,7 +235,7 @@ bgp_sock_err(sock *sk, int err)
{
case BS_CONNECT:
case BS_OPENSENT:
sk_close(conn->sk);
rfree(conn->sk);
conn->sk = NULL;
conn->state = BS_ACTIVE;
bgp_start_timer(conn->connect_retry_timer, p->cf->connect_retry_time);
......
/*
* BIRD Internet Routing Daemon -- Unix I/O
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
* (c) 1998--2004 Martin Mares <mj@ucw.cz>
* (c) 2004 Ondrej Filip <feela@network.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
......@@ -30,7 +30,6 @@
#include "lib/unix.h"
#include "lib/sysio.h"
#define LOCAL_DEBUG
/*
* Tracked Files
*/
......@@ -394,7 +393,7 @@ tm_format_reltime(char *x, bird_clock_t t)
* (@rx_hook), when the contents of the transmit buffer have been transmitted
* (@tx_hook) and when an error or connection close occurs (@err_hook).
*
* You should not use rfree() from inside a socket hook, please use sk_close() instead.
* Freeing of sockets from inside socket hooks is perfectly safe.
*/
#ifndef SOL_IP
......@@ -410,16 +409,34 @@ tm_format_reltime(char *x, bird_clock_t t)
#endif
static list sock_list;
static struct birdsock *current_sock;
static int sock_recalc_fdsets_p;
static inline sock *
sk_next(sock *s)
{
if (!s->n.next->next)
return NULL;
else
return SKIP_BACK(sock, n, s->n.next);
}
static void
sk_free(resource *r)
{
sock *s = (sock *) r;
if (s->rbuf_alloc)
xfree(s->rbuf_alloc);
if (s->tbuf_alloc)
xfree(s->tbuf_alloc);
if (s->fd >= 0)
{
close(s->fd);
if (s == current_sock)
current_sock = sk_next(s);
rem_node(&s->n);
sock_recalc_fdsets_p = 1;
}
}
......@@ -474,12 +491,16 @@ sk_new(pool *p)
s->tbsize = 0;
s->err_hook = NULL;
s->fd = -1;
s->entered = 0;
s->rbuf_alloc = s->tbuf_alloc = NULL;
return s;
}
#define ERR(x) do { err = x; goto bad; } while(0)
#define WARN(x) log(L_WARN "sk_setup: %s: %m", x)
static void
sk_insert(sock *s)
{
add_tail(&sock_list, &s->n);
sock_recalc_fdsets_p = 1;
}
#ifdef IPV6
......@@ -534,6 +555,9 @@ get_sockaddr(struct sockaddr_in *sa, ip_addr *a, unsigned *port, int check)
#endif
#define ERR(x) do { err = x; goto bad; } while(0)
#define WARN(x) log(L_WARN "sk_setup: %s: %m", x)
static char *
sk_setup(sock *s)
{
......@@ -566,10 +590,10 @@ static void
sk_alloc_bufs(sock *s)
{
if (!s->rbuf && s->rbsize)
s->rbuf = mb_alloc(s->pool, s->rbsize);
s->rbuf = s->rbuf_alloc = xmalloc(s->rbsize);
s->rpos = s->rbuf;
if (!s->tbuf && s->tbsize)
s->tbuf = mb_alloc(s->pool, s->tbsize);
s->tbuf = s->tbuf_alloc = xmalloc(s->tbsize);
s->tpos = s->ttx = s->tbuf;
}
......@@ -597,7 +621,7 @@ sk_passive_connected(sock *s, struct sockaddr *sa, int al, int type)
t->tbsize = s->tbsize;
if (type == SK_TCP)
get_sockaddr((sockaddr *) sa, &t->daddr, &t->dport, 1);
add_tail(&sock_list, &t->n);
sk_insert(t);
if (err = sk_setup(t))
{
log(L_ERR "Incoming connection: %s: %m", err);
......@@ -663,9 +687,8 @@ sk_open(sock *s)
s->fd = fd;
if (err = sk_setup(s))
{
goto bad;
}
switch (type)
{
case SK_UDP:
......@@ -769,7 +792,7 @@ sk_open(sock *s)
#endif
}
add_tail(&sock_list, &s->n);
sk_insert(s);
return 0;
bad:
......@@ -799,7 +822,7 @@ sk_open_unix(sock *s, char *name)
ERR("bind");
if (listen(fd, 8))
ERR("listen");
add_tail(&sock_list, &s->n);
sk_insert(s);
return 0;
bad:
......@@ -809,23 +832,6 @@ bad:
return -1;
}
/**
* sk_close - close a socket
* @s: a socket
*
* If sk_close() has been called from outside of any socket hook,
* it translates to a rfree(), else it just marks the socket for
* deletion as soon as the socket hook returns.
*/
void
sk_close(sock *s)
{
if (s && s->entered)
s->type = SK_DELETED;
else
rfree(s);
}
static int
sk_maybe_write(sock *s)
{
......@@ -954,15 +960,17 @@ sk_read(sock *s)
{
s->rpos += c;
if (s->rx_hook(s, s->rpos - s->rbuf))
s->rpos = s->rbuf;
{
/* We need to be careful since the socket could have been deleted by the hook */
if (current_sock == s)
s->rpos = s->rbuf;
}
return 1;
}
return 0;
}
case SK_MAGIC:
return s->rx_hook(s, 0);
case SK_DELETED:
return 0;
default:
{
sockaddr sa;
......@@ -983,7 +991,7 @@ sk_read(sock *s)
}
}
static void
static int
sk_write(sock *s)
{
switch (s->type)
......@@ -996,13 +1004,15 @@ sk_write(sock *s)
sk_tcp_connected(s);
else if (errno != EINTR && errno != EAGAIN && errno != EINPROGRESS)
s->err_hook(s, errno);
break;
return 0;
}
case SK_DELETED:
return;
default:
while (s->ttx != s->tpos && sk_maybe_write(s) > 0)
s->tx_hook(s);
if (s->ttx != s->tpos && sk_maybe_write(s) > 0)
{
s->tx_hook(s);
return 1;
}
return 0;
}
}
......@@ -1052,10 +1062,9 @@ io_loop(void)
time_t tout;
int hi, events;
sock *s;
node *n, *p;
node *n;
FD_ZERO(&rd);
FD_ZERO(&wr);
sock_recalc_fdsets_p = 1;
for(;;)
{
events = ev_run_list(&global_event_list);
......@@ -1069,6 +1078,13 @@ io_loop(void)
timo.tv_sec = events ? 0 : tout - now;
timo.tv_usec = 0;
if (sock_recalc_fdsets_p)
{
sock_recalc_fdsets_p = 0;
FD_ZERO(&rd);
FD_ZERO(&wr);
}
hi = 0;
WALK_LIST(n, sock_list)
{
......@@ -1079,12 +1095,16 @@ io_loop(void)
if (s->fd > hi)
hi = s->fd;
}
else
FD_CLR(s->fd, &rd);
if (s->tx_hook && s->ttx != s->tpos)
{
FD_SET(s->fd, &wr);
if (s->fd > hi)
hi = s->fd;
}
else
FD_CLR(s->fd, &wr);
}
/*
......@@ -1122,24 +1142,29 @@ io_loop(void)
}
if (hi)
{
WALK_LIST_DELSAFE(n, p, sock_list)
current_sock = SKIP_BACK(sock, n, HEAD(sock_list)); /* guaranteed to be non-empty */
while (current_sock)
{
s = SKIP_BACK(sock, n, n);
s->entered = 1;
sock *s = current_sock;
int e;
if (FD_ISSET(s->fd, &rd))
{
FD_CLR(s->fd, &rd);
while (sk_read(s))
;
}
if (s->type != SK_DELETED && FD_ISSET(s->fd, &wr))
{
FD_CLR(s->fd, &wr);
sk_write(s);
}
s->entered = 0;
if (s->type == SK_DELETED)
rfree(s);
do
{
e = sk_read(s);
if (s != current_sock)
goto next;
}
while (e);
if (FD_ISSET(s->fd, &wr))
do
{
e = sk_write(s);
if (s != current_sock)
goto next;
}
while (e);
current_sock = sk_next(s);
next: ;
}
}
}
......
......@@ -249,7 +249,7 @@ cli_err(sock *s, int err)
log(L_INFO "CLI connection closed");
}
cli_free(s->data);
sk_close(s);
rfree(s);
}
static int
......
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