diff options
Diffstat (limited to 'cpukit/libnetworking/netinet/in_rmx.c')
| -rw-r--r-- | cpukit/libnetworking/netinet/in_rmx.c | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/cpukit/libnetworking/netinet/in_rmx.c b/cpukit/libnetworking/netinet/in_rmx.c new file mode 100644 index 0000000000..e21ae4a59c --- /dev/null +++ b/cpukit/libnetworking/netinet/in_rmx.c @@ -0,0 +1,387 @@ +/* + * Copyright 1994, 1995 Massachusetts Institute of Technology + * + * Permission to use, copy, modify, and distribute this software and + * its documentation for any purpose and without fee is hereby + * granted, provided that both the above copyright notice and this + * permission notice appear in all copies, that both the above + * copyright notice and this permission notice appear in all + * supporting documentation, and that the name of M.I.T. not be used + * in advertising or publicity pertaining to distribution of the + * software without specific, written prior permission. M.I.T. makes + * no representations about the suitability of this software for any + * purpose. It is provided "as is" without express or implied + * warranty. + * + * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS + * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT + * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $Id$ + */ + +/* + * This code does two things necessary for the enhanced TCP metrics to + * function in a useful manner: + * 1) It marks all non-host routes as `cloning', thus ensuring that + * every actual reference to such a route actually gets turned + * into a reference to a host route to the specific destination + * requested. + * 2) When such routes lose all their references, it arranges for them + * to be deleted in some random collection of circumstances, so that + * a large quantity of stale routing data is not kept in kernel memory + * indefinitely. See in_rtqtimo() below for the exact mechanism. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/sysctl.h> +#include <sys/queue.h> +#include <sys/socket.h> +#include <sys/socketvar.h> +#include <sys/mbuf.h> +#include <sys/syslog.h> + +#include <net/if.h> +#include <net/route.h> +#include <netinet/in.h> +#include <netinet/in_systm.h> +#include <netinet/in_var.h> + +#include <netinet/ip.h> +#include <netinet/ip_var.h> + +#include <netinet/tcp.h> +#include <netinet/tcp_seq.h> +#include <netinet/tcp_timer.h> +#include <netinet/tcp_var.h> + +extern int in_inithead(void **head, int off); + +#define RTPRF_OURS RTF_PROTO3 /* set on routes we manage */ + +/* + * Do what we need to do when inserting a route. + */ +static struct radix_node * +in_addroute(void *v_arg, void *n_arg, struct radix_node_head *head, + struct radix_node *treenodes) +{ + struct rtentry *rt = (struct rtentry *)treenodes; + struct sockaddr_in *sin = (struct sockaddr_in *)rt_key(rt); + struct radix_node *ret; + + /* + * For IP, all unicast non-host routes are automatically cloning. + */ + if(IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) + rt->rt_flags |= RTF_MULTICAST; + + if(!(rt->rt_flags & (RTF_HOST | RTF_CLONING | RTF_MULTICAST))) { + rt->rt_flags |= RTF_PRCLONING; + } + + /* + * A little bit of help for both IP output and input: + * For host routes, we make sure that RTF_BROADCAST + * is set for anything that looks like a broadcast address. + * This way, we can avoid an expensive call to in_broadcast() + * in ip_output() most of the time (because the route passed + * to ip_output() is almost always a host route). + * + * We also do the same for local addresses, with the thought + * that this might one day be used to speed up ip_input(). + * + * We also mark routes to multicast addresses as such, because + * it's easy to do and might be useful (but this is much more + * dubious since it's so easy to inspect the address). (This + * is done above.) + */ + if (rt->rt_flags & RTF_HOST) { + if (in_broadcast(sin->sin_addr, rt->rt_ifp)) { + rt->rt_flags |= RTF_BROADCAST; + } else { +#define satosin(sa) ((struct sockaddr_in *)sa) + if (satosin(rt->rt_ifa->ifa_addr)->sin_addr.s_addr + == sin->sin_addr.s_addr) + rt->rt_flags |= RTF_LOCAL; +#undef satosin + } + } + + /* + * We also specify a send and receive pipe size for every + * route added, to help TCP a bit. TCP doesn't actually + * want a true pipe size, which would be prohibitive in memory + * costs and is hard to compute anyway; it simply uses these + * values to size its buffers. So, we fill them in with the + * same values that TCP would have used anyway, and allow the + * installing program or the link layer to override these values + * as it sees fit. This will hopefully allow TCP more + * opportunities to save its ssthresh value. + */ + if (!rt->rt_rmx.rmx_sendpipe && !(rt->rt_rmx.rmx_locks & RTV_SPIPE)) + rt->rt_rmx.rmx_sendpipe = tcp_sendspace; + + if (!rt->rt_rmx.rmx_recvpipe && !(rt->rt_rmx.rmx_locks & RTV_RPIPE)) + rt->rt_rmx.rmx_recvpipe = tcp_recvspace; + + if (!rt->rt_rmx.rmx_mtu && !(rt->rt_rmx.rmx_locks & RTV_MTU) + && rt->rt_ifp) + rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; + + ret = rn_addroute(v_arg, n_arg, head, treenodes); + if (ret == NULL && rt->rt_flags & RTF_HOST) { + struct rtentry *rt2; + /* + * We are trying to add a host route, but can't. + * Find out if it is because of an + * ARP entry and delete it if so. + */ + rt2 = rtalloc1((struct sockaddr *)sin, 0, + RTF_CLONING | RTF_PRCLONING); + if (rt2) { + if (rt2->rt_flags & RTF_LLINFO && + rt2->rt_flags & RTF_HOST && + rt2->rt_gateway && + rt2->rt_gateway->sa_family == AF_LINK) { + rtrequest(RTM_DELETE, + (struct sockaddr *)rt_key(rt2), + rt2->rt_gateway, + rt_mask(rt2), rt2->rt_flags, 0); + ret = rn_addroute(v_arg, n_arg, head, + treenodes); + } + RTFREE(rt2); + } + } + return ret; +} + +/* + * This code is the inverse of in_clsroute: on first reference, if we + * were managing the route, stop doing so and set the expiration timer + * back off again. + */ +static struct radix_node * +in_matroute(void *v_arg, struct radix_node_head *head) +{ + struct radix_node *rn = rn_match(v_arg, head); + struct rtentry *rt = (struct rtentry *)rn; + + if(rt && rt->rt_refcnt == 0) { /* this is first reference */ + if(rt->rt_flags & RTPRF_OURS) { + rt->rt_flags &= ~RTPRF_OURS; + rt->rt_rmx.rmx_expire = 0; + } + } + return rn; +} + +static int rtq_reallyold = 60*60; + /* one hour is ``really old'' */ +SYSCTL_INT(_net_inet_ip, IPCTL_RTEXPIRE, rtexpire, + CTLFLAG_RW, &rtq_reallyold , 0, ""); + +static int rtq_minreallyold = 10; + /* never automatically crank down to less */ +SYSCTL_INT(_net_inet_ip, IPCTL_RTMINEXPIRE, rtminexpire, + CTLFLAG_RW, &rtq_minreallyold , 0, ""); + +static int rtq_toomany = 128; + /* 128 cached routes is ``too many'' */ +SYSCTL_INT(_net_inet_ip, IPCTL_RTMAXCACHE, rtmaxcache, + CTLFLAG_RW, &rtq_toomany , 0, ""); + + +/* + * On last reference drop, mark the route as belong to us so that it can be + * timed out. + */ +static void +in_clsroute(struct radix_node *rn, struct radix_node_head *head) +{ + struct rtentry *rt = (struct rtentry *)rn; + + if(!(rt->rt_flags & RTF_UP)) + return; /* prophylactic measures */ + + if((rt->rt_flags & (RTF_LLINFO | RTF_HOST)) != RTF_HOST) + return; + + if((rt->rt_flags & (RTF_WASCLONED | RTPRF_OURS)) + != RTF_WASCLONED) + return; + + /* + * As requested by David Greenman: + * If rtq_reallyold is 0, just delete the route without + * waiting for a timeout cycle to kill it. + */ + if(rtq_reallyold != 0) { + rt->rt_flags |= RTPRF_OURS; + rt->rt_rmx.rmx_expire = rtems_bsdnet_seconds_since_boot() + rtq_reallyold; + } else { + rtrequest(RTM_DELETE, + (struct sockaddr *)rt_key(rt), + rt->rt_gateway, rt_mask(rt), + rt->rt_flags, 0); + } +} + +struct rtqk_arg { + struct radix_node_head *rnh; + int draining; + int killed; + int found; + int updating; + time_t nextstop; +}; + +/* + * Get rid of old routes. When draining, this deletes everything, even when + * the timeout is not expired yet. When updating, this makes sure that + * nothing has a timeout longer than the current value of rtq_reallyold. + */ +static int +in_rtqkill(struct radix_node *rn, void *rock) +{ + struct rtqk_arg *ap = rock; + struct rtentry *rt = (struct rtentry *)rn; + int err; + + if(rt->rt_flags & RTPRF_OURS) { + ap->found++; + + if(ap->draining || rt->rt_rmx.rmx_expire <= rtems_bsdnet_seconds_since_boot()) { + if(rt->rt_refcnt > 0) + panic("rtqkill route really not free"); + + err = rtrequest(RTM_DELETE, + (struct sockaddr *)rt_key(rt), + rt->rt_gateway, rt_mask(rt), + rt->rt_flags, 0); + if(err) { + log(LOG_WARNING, "in_rtqkill: error %d\n", err); + } else { + ap->killed++; + } + } else { + if(ap->updating + && (rt->rt_rmx.rmx_expire - rtems_bsdnet_seconds_since_boot() + > rtq_reallyold)) { + rt->rt_rmx.rmx_expire = rtems_bsdnet_seconds_since_boot() + + rtq_reallyold; + } + ap->nextstop = lmin(ap->nextstop, + rt->rt_rmx.rmx_expire); + } + } + + return 0; +} + +#define RTQ_TIMEOUT 60*10 /* run no less than once every ten minutes */ +static int rtq_timeout = RTQ_TIMEOUT; + +static void +in_rtqtimo(void *rock) +{ + struct radix_node_head *rnh = rock; + struct rtqk_arg arg; + struct timeval atv; + static time_t last_adjusted_timeout = 0; + int s; + + arg.found = arg.killed = 0; + arg.rnh = rnh; + arg.nextstop = rtems_bsdnet_seconds_since_boot() + rtq_timeout; + arg.draining = arg.updating = 0; + s = splnet(); + rnh->rnh_walktree(rnh, in_rtqkill, &arg); + splx(s); + + /* + * Attempt to be somewhat dynamic about this: + * If there are ``too many'' routes sitting around taking up space, + * then crank down the timeout, and see if we can't make some more + * go away. However, we make sure that we will never adjust more + * than once in rtq_timeout seconds, to keep from cranking down too + * hard. + */ + if((arg.found - arg.killed > rtq_toomany) + && (rtems_bsdnet_seconds_since_boot() - last_adjusted_timeout >= rtq_timeout) + && rtq_reallyold > rtq_minreallyold) { + rtq_reallyold = 2*rtq_reallyold / 3; + if(rtq_reallyold < rtq_minreallyold) { + rtq_reallyold = rtq_minreallyold; + } + + last_adjusted_timeout = rtems_bsdnet_seconds_since_boot(); +#ifdef DIAGNOSTIC + log(LOG_DEBUG, "in_rtqtimo: adjusted rtq_reallyold to %d\n", + rtq_reallyold); +#endif + arg.found = arg.killed = 0; + arg.updating = 1; + s = splnet(); + rnh->rnh_walktree(rnh, in_rtqkill, &arg); + splx(s); + } + + atv.tv_usec = 0; + atv.tv_sec = arg.nextstop; + timeout(in_rtqtimo, rock, hzto(&atv)); +} + +void +in_rtqdrain(void) +{ + struct radix_node_head *rnh = rt_tables[AF_INET]; + struct rtqk_arg arg; + int s; + arg.found = arg.killed = 0; + arg.rnh = rnh; + arg.nextstop = 0; + arg.draining = 1; + arg.updating = 0; + s = splnet(); + rnh->rnh_walktree(rnh, in_rtqkill, &arg); + splx(s); +} + +/* + * Initialize our routing tree. + */ +int +in_inithead(void **head, int off) +{ + struct radix_node_head *rnh; + + if(!rn_inithead(head, off)) + return 0; + + if(head != (void **)&rt_tables[AF_INET]) /* BOGUS! */ + return 1; /* only do this for the real routing table */ + + rnh = *head; + rnh->rnh_addaddr = in_addroute; + rnh->rnh_matchaddr = in_matroute; + rnh->rnh_close = in_clsroute; + in_rtqtimo(rnh); /* kick off timeout first time */ + return 1; +} |