diff options
Diffstat (limited to 'sys/netinet/ip_dummynet.c')
| -rw-r--r-- | sys/netinet/ip_dummynet.c | 644 |
1 files changed, 644 insertions, 0 deletions
diff --git a/sys/netinet/ip_dummynet.c b/sys/netinet/ip_dummynet.c new file mode 100644 index 0000000..401e24d --- /dev/null +++ b/sys/netinet/ip_dummynet.c @@ -0,0 +1,644 @@ +/* + * Copyright (c) 1998 Luigi Rizzo + * + * Redistribution and use in source forms, with and without modification, + * are permitted provided that this entire comment appears intact. + * + * Redistribution in binary form may occur without any restrictions. + * Obviously, it would be nice if you gave credit where credit is due + * but requiring it would be too onerous. + * + * This software is provided ``AS IS'' without any warranties of any kind. + * + * $FreeBSD$ + */ + +/* + * This module implements IP dummynet, a bandwidth limiter/delay emulator + * used in conjunction with the ipfw package. + * + * Changes: + * + * 980821: changed conventions in the queueing logic + * packets passed from dummynet to ip_in/out are prepended with + * a vestigial mbuf type MT_DUMMYNET which contains a pointer + * to the matching rule. + * ip_input/output will extract the parameters, free the vestigial mbuf, + * and do the processing. + * + * 980519: fixed behaviour when deleting rules. + * 980518: added splimp()/splx() to protect against races + * 980513: initial release + */ + +/* include files marked with XXX are probably not needed */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/malloc.h> +#include <sys/mbuf.h> +#include <sys/queue.h> /* XXX */ +#include <sys/kernel.h> +#include <sys/module.h> +#include <sys/socket.h> +#include <sys/socketvar.h> +#include <sys/time.h> +#include <sys/sysctl.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_fw.h> +#include <netinet/ip_dummynet.h> +#include <netinet/ip_var.h> + +#include "opt_bdg.h" +#ifdef BRIDGE +#include <netinet/if_ether.h> /* for struct arpcom */ +#include <net/bridge.h> +#endif + +static struct dn_pipe *all_pipes = NULL ; /* list of all pipes */ + +static int dn_debug = 0 ; /* verbose */ +static int dn_calls = 0 ; /* number of calls */ +static int dn_idle = 1; +#ifdef SYSCTL_NODE +SYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet, CTLFLAG_RW, 0, "Dummynet"); +SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, debug, CTLFLAG_RW, &dn_debug, 0, ""); +SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, calls, CTLFLAG_RD, &dn_calls, 0, ""); +SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, idle, CTLFLAG_RD, &dn_idle, 0, ""); +#endif + +static int ip_dn_ctl(struct sockopt *sopt); + +static void rt_unref(struct rtentry *); +static void dummynet(void *); +static void dn_restart(void); +static void dn_move(struct dn_pipe *pipe, int immediate); +static void dummynet_flush(void); + +/* + * the following is needed when deleting a pipe, because rules can + * hold references to the pipe. + */ +extern LIST_HEAD (ip_fw_head, ip_fw_chain) ip_fw_chain; + +/* + * invoked to reschedule the periodic task if necessary. + * Should only be called when dn_idle = 1 ; + */ +static void +dn_restart() +{ + struct dn_pipe *pipe; + + if (!dn_idle) + return; + + for (pipe = all_pipes ; pipe ; pipe = pipe->next ) { + /* if there any pipe that needs work, restart */ + if (pipe->r.head || pipe->p.head || pipe->numbytes < 0 ) { + dn_idle = 0; + timeout(dummynet, NULL, 1); + return ; + } + } +} + +static void +rt_unref(struct rtentry *rt) +{ + if (rt == NULL) + return ; + if (rt->rt_refcnt <= 0) + printf("-- warning, refcnt now %ld, decreasing\n", rt->rt_refcnt); + RTFREE(rt); +} + +/* + * move packets from R-queue to P-queue + */ +static void +dn_move(struct dn_pipe *pipe, int immediate) +{ + struct dn_pkt *pkt; + + /* + * consistency check, should catch new pipes which are + * not initialized properly. + */ + if ( pipe->p.head == NULL && + pipe->ticks_from_last_insert != pipe->delay) { + printf("Warning, empty pipe and delay %d (should be %d)\n", + pipe->ticks_from_last_insert, pipe->delay); + pipe->ticks_from_last_insert = pipe->delay; + } + /* this ought to go in dn_dequeue() */ + if (!immediate && pipe->ticks_from_last_insert < pipe->delay) + pipe->ticks_from_last_insert++; + if ((pkt = pipe->r.head) != NULL) { + /* + * Move at most numbytes bytes from src and move to dst. + * delay is set to ticks_from_last_insert, which + * is reset after the first insertion; + */ + while ( pkt ) { + int len = pkt->dn_m->m_pkthdr.len ; + + /* + * queue limitation: pass packets down if the len is + * such that the pkt would go out before the next tick. + */ + if (pipe->bandwidth) { + int len_scaled = len*8*hz ; + /* numbytes is in bit/sec, scaled 8*hz ... */ + if (pipe->numbytes < len_scaled) + break; + pipe->numbytes -= len_scaled; + } + pipe->r_len--; /* elements in queue */ + pipe->r_len_bytes -= len ; + + /* + * to add delay jitter, must act here. A lower value + * (bounded to 0) means lower delay. + */ + pkt->delay = pipe->ticks_from_last_insert; + pipe->ticks_from_last_insert = 0; + /* compensate the decrement done next in dn_dequeue */ + if (!immediate && pkt->delay >0 && pipe->p.head==NULL) + pkt->delay++; + if (pipe->p.head == NULL) + pipe->p.head = pkt; + else + (struct dn_pkt *)pipe->p.tail->dn_next = pkt; + pipe->p.tail = pkt; + pkt = (struct dn_pkt *)pkt->dn_next; + pipe->p.tail->dn_next = NULL; + } + pipe->r.head = pkt; + + /*** XXX just a sanity check */ + if ( ( pkt == NULL && pipe->r_len != 0) || + ( pkt != NULL && pipe->r_len == 0) ) + printf("-- Warning, pipe head %p len %d\n", + (void *)pkt, pipe->r_len); + } + + /* + * deliver packets downstream after the delay in the P-queue. + */ + + if (pipe->p.head == NULL) + return; + if (!immediate) + pipe->p.head->delay--; + while ( (pkt = pipe->p.head) && pkt->delay < 1) { + /* + * first unlink, then call procedures since ip_input() + * can result in a call to ip_output cnd viceversa, + * thus causing nested calls + */ + pipe->p.head = (struct dn_pkt *) pkt->dn_next ; + + /* + * the trick to avoid flow-id settings here is to prepend a + * vestigial mbuf to the packet, with the following values: + * m_type = MT_DUMMYNET + * m_next = the actual mbuf to be processed by ip_input/output + * m_data = the matching rule + * The vestigial element is the same memory area used by + * the dn_pkt, and IS FREED HERE because it can contain + * parameters passed to the called routine. The buffer IS NOT + * A REAL MBUF, just a block of memory acquired with malloc(). + */ + switch (pkt->dn_dir) { + case DN_TO_IP_OUT: { + struct route *ro = &(pkt->ro) ; + + (void)ip_output((struct mbuf *)pkt, (struct mbuf *)pkt->ifp, + ro, pkt->dn_dst, NULL); + rt_unref (ro->ro_rt) ; + } + break ; + case DN_TO_IP_IN : + ip_input((struct mbuf *)pkt) ; + break ; +#ifdef BRIDGE + case DN_TO_BDG_FWD : { + struct mbuf *m = (struct mbuf *)pkt ; + + bdg_forward(&m, pkt->ifp); + if (m) + m_freem(m); + } + break ; +#endif + default: + printf("dummynet: bad switch %d!\n", pkt->dn_dir); + m_freem(pkt->dn_m); + break ; + } + FREE(pkt, M_IPFW); + } +} +/* + * this is the periodic task that moves packets between the R- + * and the P- queue + */ +/*ARGSUSED*/ +void +dummynet(void * __unused unused) +{ + struct dn_pipe *p ; + int s ; + + dn_calls++ ; + for (p = all_pipes ; p ; p = p->next ) { + /* + * Increment the amount of data that can be sent. However, + * don't do that if the channel is idle + * (r.head == NULL && numbytes >= bandwidth). + * This bug fix is from tim shepard (shep@bbn.com) + */ + s = splimp(); + if (p->r.head != NULL || p->numbytes < p->bandwidth ) + p->numbytes += p->bandwidth ; + dn_move(p, 0); /* is it really 0 (also below) ? */ + splx(s); + } + + /* + * finally, if some queue has data, restart the timer. + */ + s = splimp(); + dn_idle = 1; + dn_restart(); + splx(s); +} + +/* + * dummynet hook for packets. + * input and output use the same code, so i use bit 16 in the pipe + * number to chose the direction: 1 for output packets, 0 for input. + * for input, only m is significant. For output, also the others. + */ +int +dummynet_io(int pipe_nr, int dir, + struct mbuf *m, struct ifnet *ifp, struct route *ro, + struct sockaddr_in *dst, + struct ip_fw_chain *rule) +{ + struct dn_pkt *pkt; + struct dn_pipe *pipe; + int len = m->m_pkthdr.len ; + + int s=splimp(); + + pipe_nr &= 0xffff ; + /* + * locate pipe. First time is expensive, next have direct access. + */ + + if ( (pipe = rule->rule->pipe_ptr) == NULL ) { + for (pipe=all_pipes; pipe && pipe->pipe_nr !=pipe_nr; pipe=pipe->next) + ; + if (pipe == NULL) { + splx(s); + if (dn_debug) + printf("warning, pkt for no pipe %d\n", pipe_nr); + m_freem(m); + return 0 ; + } else + rule->rule->pipe_ptr = pipe ; + } + + /* + * should i drop ? + * This section implements random packet drop. + */ + if ( (pipe->plr && random() < pipe->plr) || + (pipe->queue_size && pipe->r_len >= pipe->queue_size) || + (pipe->queue_size_bytes && + len + pipe->r_len_bytes > pipe->queue_size_bytes) || + (pkt = (struct dn_pkt *)malloc(sizeof (*pkt), + M_IPFW, M_NOWAIT) ) == NULL ) { + splx(s); + if (dn_debug) + printf("-- dummynet: drop from pipe %d, have %d pks, %d bytes\n", + pipe_nr, pipe->r_len, pipe->r_len_bytes); + pipe->r_drops++ ; + m_freem(m); + return 0 ; /* XXX error */ + } + bzero(pkt, sizeof(*pkt) ); + /* build and enqueue packet */ + pkt->hdr.mh_type = MT_DUMMYNET ; + (struct ip_fw_chain *)pkt->hdr.mh_data = rule ; + pkt->dn_next = NULL; + pkt->dn_m = m; + pkt->dn_dir = dir ; + pkt->delay = 0; + + pkt->ifp = ifp; + if (dir == DN_TO_IP_OUT) { + /* + * we need to copy *ro because for icmp pkts (and maybe others) + * the caller passed a pointer into the stack. + */ + pkt->ro = *ro; + if (ro->ro_rt) + ro->ro_rt->rt_refcnt++ ; /* XXX */ + /* + * and again, dst might be a pointer into *ro... + */ + if (dst == (struct sockaddr_in *)&ro->ro_dst) /* dst points into ro */ + dst = (struct sockaddr_in *)&(pkt->ro.ro_dst) ; + + pkt->dn_dst = dst; /* XXX this can't be right! */ + } + if (pipe->r.head == NULL) + pipe->r.head = pkt; + else + (struct dn_pkt *)pipe->r.tail->dn_next = pkt; + pipe->r.tail = pkt; + pipe->r_len++; + pipe->r_len_bytes += len ; + + /* + * here we could implement RED if we like to + */ + + if (pipe->r.head == pkt) { /* process immediately */ + dn_move(pipe, 1); + } + if (dn_idle) + dn_restart(); + splx(s); + return 0; +} + +/* + * dispose all packets queued on a pipe + */ +static void +purge_pipe(struct dn_pipe *pipe) +{ + struct dn_pkt *pkt, *n ; + struct rtentry *tmp_rt ; + + for (pkt = pipe->r.head ; pkt ; ) { + rt_unref (tmp_rt = pkt->ro.ro_rt ) ; + m_freem(pkt->dn_m); + n = pkt ; + pkt = (struct dn_pkt *)pkt->dn_next ; + free(n, M_IPFW) ; + } + for (pkt = pipe->p.head ; pkt ; ) { + rt_unref (tmp_rt = pkt->ro.ro_rt ) ; + m_freem(pkt->dn_m); + n = pkt ; + pkt = (struct dn_pkt *)pkt->dn_next ; + free(n, M_IPFW) ; + } +} + +/* + * delete all pipes returning memory + */ +static void +dummynet_flush() +{ + struct dn_pipe *q, *p = all_pipes ; + int s = splnet() ; + + all_pipes = NULL ; + splx(s) ; + /* + * purge all queued pkts and delete all pipes + */ + for ( ; p ; ) { + purge_pipe(p); + q = p ; + p = p->next ; + free(q, M_IPFW); + } +} + +extern struct ip_fw_chain *ip_fw_default_rule ; +/* + * when a firewall rule is deleted, scan all pipes and remove the flow-id + * from packets matching this rule. + */ +void +dn_rule_delete(void *r) +{ + struct dn_pipe *p ; + int matches = 0 ; + + for ( p = all_pipes ; p ; p = p->next ) { + struct dn_pkt *x ; + for (x = p->r.head ; x ; x = (struct dn_pkt *)x->dn_next ) + if (x->hdr.mh_data == r) { + matches++ ; + x->hdr.mh_data = (void *)ip_fw_default_rule ; + } + for (x = p->p.head ; x ; x = (struct dn_pkt *)x->dn_next ) + if (x->hdr.mh_data == r) { + matches++ ; + x->hdr.mh_data = (void *)ip_fw_default_rule ; + } + } + printf("dn_rule_delete, r %p, default %p%s, %d matches\n", + (void *)r, (void *)ip_fw_default_rule, + r == ip_fw_default_rule ? " AARGH!":"", matches); +} + +/* + * handler for the various dummynet socket options + * (get, flush, config, del) + */ +static int +ip_dn_ctl(struct sockopt *sopt) +{ + int error = 0 ; + size_t size ; + char *buf, *bp ; + struct dn_pipe *p, tmp_pipe ; + + struct dn_pipe *x, *a, *b ; + + /* Disallow sets in really-really secure mode. */ + if (sopt->sopt_dir == SOPT_SET && securelevel >= 3) + return (EPERM); + + switch (sopt->sopt_name) { + default : + panic("ip_dn_ctl -- unknown option"); + + case IP_DUMMYNET_GET : + for (p = all_pipes, size = 0 ; p ; p = p->next ) + size += sizeof( *p ) ; + buf = malloc(size, M_TEMP, M_WAITOK); + if (buf == 0) { + error = ENOBUFS ; + break ; + } + for (p = all_pipes, bp = buf ; p ; p = p->next ) { + struct dn_pipe *q = (struct dn_pipe *)bp ; + + bcopy(p, bp, sizeof( *p ) ); + /* + * return bw and delay in bits/s and ms, respectively + */ + q->delay = (q->delay * 1000) / hz ; + bp += sizeof( *p ) ; + } + error = sooptcopyout(sopt, buf, size); + FREE(buf, M_TEMP); + break ; + case IP_DUMMYNET_FLUSH : + dummynet_flush() ; + break ; + case IP_DUMMYNET_CONFIGURE : + p = &tmp_pipe ; + error = sooptcopyin(sopt, p, sizeof *p, sizeof *p); + if (error) + break ; + /* + * The config program passes parameters as follows: + * bandwidth = bits/second (0 = no limits); + * delay = ms + * must be translated in ticks. + * queue_size = slots (0 = no limit) + * queue_size_bytes = bytes (0 = no limit) + * only one can be set, must be bound-checked + */ + p->delay = ( p->delay * hz ) / 1000 ; + if (p->queue_size == 0 && p->queue_size_bytes == 0) + p->queue_size = 50 ; + if (p->queue_size != 0 ) /* buffers are prevailing */ + p->queue_size_bytes = 0 ; + if (p->queue_size > 100) + p->queue_size = 50 ; + if (p->queue_size_bytes > 1024*1024) + p->queue_size_bytes = 1024*1024 ; +#if 0 + printf("ip_dn: config pipe %d %d bit/s %d ms %d bufs\n", + p->pipe_nr, + p->bandwidth * 8 * hz , + p->delay * 1000 / hz , p->queue_size); +#endif + for (a = NULL , b = all_pipes ; b && b->pipe_nr < p->pipe_nr ; + a = b , b = b->next) ; + if (b && b->pipe_nr == p->pipe_nr) { + /* XXX should spl and flush old pipe... */ + b->bandwidth = p->bandwidth ; + b->delay = p->delay ; + b->ticks_from_last_insert = p->delay ; + b->queue_size = p->queue_size ; + b->queue_size_bytes = p->queue_size_bytes ; + b->plr = p->plr ; + } else { + int s ; + x = malloc(sizeof(struct dn_pipe), M_IPFW, M_DONTWAIT) ; + if (x == NULL) { + printf("ip_dummynet.c: sorry no memory\n"); + error = ENOSPC ; + break ; + } + bzero(x, sizeof(*x) ); + x->bandwidth = p->bandwidth ; + x->delay = p->delay ; + x->ticks_from_last_insert = p->delay ; + x->pipe_nr = p->pipe_nr ; + x->queue_size = p->queue_size ; + x->queue_size_bytes = p->queue_size_bytes ; + x->plr = p->plr ; + + s = splnet() ; + x->next = b ; + if (a == NULL) + all_pipes = x ; + else + a->next = x ; + splx(s); + } + break ; + + case IP_DUMMYNET_DEL : + p = &tmp_pipe ; + error = sooptcopyin(sopt, p, sizeof *p, sizeof *p); + if (error) + break ; + + for (a = NULL , b = all_pipes ; b && b->pipe_nr < p->pipe_nr ; + a = b , b = b->next) ; + if (b && b->pipe_nr == p->pipe_nr) { /* found pipe */ + int s = splnet() ; + struct ip_fw_chain *chain = ip_fw_chain.lh_first; + + if (a == NULL) + all_pipes = b->next ; + else + a->next = b->next ; + /* + * remove references to this pipe from the ip_fw rules. + */ + for (; chain; chain = chain->chain.le_next) { + register struct ip_fw *const f = chain->rule; + if (f->pipe_ptr == b) + f->pipe_ptr = NULL ; + } + splx(s); + purge_pipe(b); /* remove pkts from here */ + free(b, M_IPFW); + } + break ; + } + return error ; +} + +static void +ip_dn_init(void) +{ + printf("DUMMYNET initialized (990811)\n"); + all_pipes = NULL ; + ip_dn_ctl_ptr = ip_dn_ctl; +} + +static ip_dn_ctl_t *old_dn_ctl_ptr; + +static int +dummynet_modevent(module_t mod, int type, void *data) +{ + int s; + + switch (type) { + case MOD_LOAD: + s = splnet(); + old_dn_ctl_ptr = ip_dn_ctl_ptr; + ip_dn_init(); + splx(s); + break; + case MOD_UNLOAD: + s = splnet(); + ip_dn_ctl_ptr = old_dn_ctl_ptr; + splx(s); + dummynet_flush(); + break; + default: + break; + } + return 0; +} + +static moduledata_t dummynet_mod = { + "dummynet", + dummynet_modevent, + NULL +}; +DECLARE_MODULE(dummynet, dummynet_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); |
