/* net/sched/sch_atm.c - ATM VC selection "queueing discipline" */ /* Written 1998-2000 by Werner Almesberger, EPFL ICA */ #include <linux/config.h> #include <linux/module.h> #include <linux/init.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/skbuff.h> #include <linux/interrupt.h> #include <linux/atmdev.h> #include <linux/atmclip.h> #include <linux/netdevice.h> #include <linux/rtnetlink.h> #include <linux/file.h> /* for fput */ #include <net/pkt_sched.h> #include <net/sock.h> extern struct socket *sockfd_lookup(int fd, int *err); /* @@@ fix this */ #if 0 /* control */ #define DPRINTK(format,args...) printk(KERN_DEBUG format,##args) #else #define DPRINTK(format,args...) #endif #if 0 /* data */ #define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args) #else #define D2PRINTK(format,args...) #endif /* * The ATM queuing discipline provides a framework for invoking classifiers * (aka "filters"), which in turn select classes of this queuing discipline. * Each class maps the flow(s) it is handling to a given VC. Multiple classes * may share the same VC. * * When creating a class, VCs are specified by passing the number of the open * socket descriptor by which the calling process references the VC. The kernel * keeps the VC open at least until all classes using it are removed. * * In this file, most functions are named atm_tc_* to avoid confusion with all * the atm_* in net/atm. This naming convention differs from what's used in the * rest of net/sched. * * Known bugs: * - sometimes messes up the IP stack * - any manipulations besides the few operations described in the README, are * untested and likely to crash the system * - should lock the flow while there is data in the queue (?) */ #define PRIV(sch) ((struct atm_qdisc_data *) (sch)->data) #define VCC2FLOW(vcc) ((struct atm_flow_data *) ((vcc)->user_back)) struct atm_flow_data { struct Qdisc *q; /* FIFO, TBF, etc. */ struct tcf_proto *filter_list; struct atm_vcc *vcc; /* VCC; NULL if VCC is closed */ void (*old_pop)(struct atm_vcc *vcc,struct sk_buff *skb); /* chaining */ struct atm_qdisc_data *parent; /* parent qdisc */ struct socket *sock; /* for closing */ u32 classid; /* x:y type ID */ int ref; /* reference count */ struct tc_stats stats; struct atm_flow_data *next; struct atm_flow_data *excess; /* flow for excess traffic; NULL to set CLP instead */ int hdr_len; unsigned char hdr[0]; /* header data; MUST BE LAST */ }; struct atm_qdisc_data { struct atm_flow_data link; /* unclassified skbs go here */ struct atm_flow_data *flows; /* NB: "link" is also on this list */ struct tasklet_struct task; /* requeue tasklet */ }; /* ------------------------- Class/flow operations ------------------------- */ static int find_flow(struct atm_qdisc_data *qdisc,struct atm_flow_data *flow) { struct atm_flow_data *walk; DPRINTK("find_flow(qdisc %p,flow %p)\n",qdisc,flow); for (walk = qdisc->flows; walk; walk = walk->next) if (walk == flow) return 1; DPRINTK("find_flow: not found\n"); return 0; } static __inline__ struct atm_flow_data *lookup_flow(struct Qdisc *sch, u32 classid) { struct atm_flow_data *flow; for (flow = PRIV(sch)->flows; flow; flow = flow->next) if (flow->classid == classid) break; return flow; } static int atm_tc_graft(struct Qdisc *sch,unsigned long arg, struct Qdisc *new,struct Qdisc **old) { struct atm_qdisc_data *p = PRIV(sch); struct atm_flow_data *flow = (struct atm_flow_data *) arg; DPRINTK("atm_tc_graft(sch %p,[qdisc %p],flow %p,new %p,old %p)\n",sch, p,flow,new,old); if (!find_flow(p,flow)) return -EINVAL; if (!new) new = &noop_qdisc; *old = xchg(&flow->q,new); if (*old) qdisc_reset(*old); return 0; } static struct Qdisc *atm_tc_leaf(struct Qdisc *sch,unsigned long cl) { struct atm_flow_data *flow = (struct atm_flow_data *) cl; DPRINTK("atm_tc_leaf(sch %p,flow %p)\n",sch,flow); return flow ? flow->q : NULL; } static unsigned long atm_tc_get(struct Qdisc *sch,u32 classid) { struct atm_qdisc_data *p __attribute__((unused)) = PRIV(sch); struct atm_flow_data *flow; DPRINTK("atm_tc_get(sch %p,[qdisc %p],classid %x)\n",sch,p,classid); flow = lookup_flow(sch,classid); if (flow) flow->ref++; DPRINTK("atm_tc_get: flow %p\n",flow); return (unsigned long) flow; } static unsigned long atm_tc_bind_filter(struct Qdisc *sch, unsigned long parent, u32 classid) { return atm_tc_get(sch,classid); } static void destroy_filters(struct atm_flow_data *flow) { struct tcf_proto *filter; while ((filter = flow->filter_list)) { DPRINTK("destroy_filters: destroying filter %p\n",filter); flow->filter_list = filter->next; tcf_destroy(filter); } } /* * atm_tc_put handles all destructions, including the ones that are explicitly * requested (atm_tc_destroy, etc.). The assumption here is that we never drop * anything that still seems to be in use. */ static void atm_tc_put(struct Qdisc *sch, unsigned long cl) { struct atm_qdisc_data *p = PRIV(sch); struct atm_flow_data *flow = (struct atm_flow_data *) cl; struct atm_flow_data **prev; DPRINTK("atm_tc_put(sch %p,[qdisc %p],flow %p)\n",sch,p,flow); if (--flow->ref) return; DPRINTK("atm_tc_put: destroying\n"); for (prev = &p->flows; *prev; prev = &(*prev)->next) if (*prev == flow) break; if (!*prev) { printk(KERN_CRIT "atm_tc_put: class %p not found\n",flow); return; } *prev = flow->next; DPRINTK("atm_tc_put: qdisc %p\n",flow->q); qdisc_destroy(flow->q); destroy_filters(flow); if (flow->sock) { DPRINTK("atm_tc_put: f_count %d\n", file_count(flow->sock->file)); flow->vcc->pop = flow->old_pop; sockfd_put(flow->sock); } if (flow->excess) atm_tc_put(sch,(unsigned long) flow->excess); if (flow != &p->link) kfree(flow); /* * If flow == &p->link, the qdisc no longer works at this point and * needs to be removed. (By the caller of atm_tc_put.) */ } static void sch_atm_pop(struct atm_vcc *vcc,struct sk_buff *skb) { struct atm_qdisc_data *p = VCC2FLOW(vcc)->parent; D2PRINTK("sch_atm_pop(vcc %p,skb %p,[qdisc %p])\n",vcc,skb,p); VCC2FLOW(vcc)->old_pop(vcc,skb); tasklet_schedule(&p->task); } static const u8 llc_oui_ip[] = { 0xaa, /* DSAP: non-ISO */ 0xaa, /* SSAP: non-ISO */ 0x03, /* Ctrl: Unnumbered Information Command PDU */ 0x00, /* OUI: EtherType */ 0x00, 0x00, 0x08, 0x00 }; /* Ethertype IP (0800) */ static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent, struct rtattr **tca, unsigned long *arg) { struct atm_qdisc_data *p = PRIV(sch); struct atm_flow_data *flow = (struct atm_flow_data *) *arg; struct atm_flow_data *excess = NULL; struct rtattr *opt = tca[TCA_OPTIONS-1]; struct rtattr *tb[TCA_ATM_MAX]; struct socket *sock; int fd,error,hdr_len; void *hdr; DPRINTK("atm_tc_change(sch %p,[qdisc %p],classid %x,parent %x," "flow %p,opt %p)\n",sch,p,classid,parent,flow,opt); /* * The concept of parents doesn't apply for this qdisc. */ if (parent && parent != TC_H_ROOT && parent != sch->handle) return -EINVAL; /* * ATM classes cannot be changed. In order to change properties of the * ATM connection, that socket needs to be modified directly (via the * native ATM API. In order to send a flow to a different VC, the old * class needs to be removed and a new one added. (This may be changed * later.) */ if (flow) return -EBUSY; if (opt == NULL || rtattr_parse(tb,TCA_ATM_MAX,RTA_DATA(opt), RTA_PAYLOAD(opt))) return -EINVAL; if (!tb[TCA_ATM_FD-1] || RTA_PAYLOAD(tb[TCA_ATM_FD-1]) < sizeof(fd)) return -EINVAL; fd = *(int *) RTA_DATA(tb[TCA_ATM_FD-1]); DPRINTK("atm_tc_change: fd %d\n",fd); if (tb[TCA_ATM_HDR-1]) { hdr_len = RTA_PAYLOAD(tb[TCA_ATM_HDR-1]); hdr = RTA_DATA(tb[TCA_ATM_HDR-1]); } else { hdr_len = RFC1483LLC_LEN; hdr = NULL; /* default LLC/SNAP for IP */ } if (!tb[TCA_ATM_EXCESS-1]) excess = NULL; else { if (RTA_PAYLOAD(tb[TCA_ATM_EXCESS-1]) != sizeof(u32)) return -EINVAL; excess = (struct atm_flow_data *) atm_tc_get(sch, *(u32 *) RTA_DATA(tb[TCA_ATM_EXCESS-1])); if (!excess) return -ENOENT; } DPRINTK("atm_tc_change: type %d, payload %d, hdr_len %d\n", opt->rta_type,RTA_PAYLOAD(opt),hdr_len); if (!(sock = sockfd_lookup(fd,&error))) return error; /* f_count++ */ DPRINTK("atm_tc_change: f_count %d\n",file_count(sock->file)); if (sock->ops->family != PF_ATMSVC && sock->ops->family != PF_ATMPVC) { error = -EPROTOTYPE; goto err_out; } /* @@@ should check if the socket is really operational or we'll crash on vcc->send */ if (classid) { if (TC_H_MAJ(classid ^ sch->handle)) { DPRINTK("atm_tc_change: classid mismatch\n"); error = -EINVAL; goto err_out; } if (find_flow(p,flow)) { error = -EEXIST; goto err_out; } } else { int i; unsigned long cl; for (i = 1; i < 0x8000; i++) { classid = TC_H_MAKE(sch->handle,0x8000 | i); if (!(cl = atm_tc_get(sch,classid))) break; atm_tc_put(sch,cl); } } DPRINTK("atm_tc_change: new id %x\n",classid); flow = kmalloc(sizeof(struct atm_flow_data)+hdr_len,GFP_KERNEL); DPRINTK("atm_tc_change: flow %p\n",flow); if (!flow) { error = -ENOBUFS; goto err_out; } memset(flow,0,sizeof(*flow)); flow->filter_list = NULL; if (!(flow->q = qdisc_create_dflt(sch->dev,&pfifo_qdisc_ops))) flow->q = &noop_qdisc; DPRINTK("atm_tc_change: qdisc %p\n",flow->q); flow->sock = sock; flow->vcc = ATM_SD(sock); /* speedup */ flow->vcc->user_back = flow; DPRINTK("atm_tc_change: vcc %p\n",flow->vcc); flow->old_pop = flow->vcc->pop; flow->parent = p; flow->vcc->pop = sch_atm_pop; flow->classid = classid; flow->ref = 1; flow->excess = excess; flow->next = p->link.next; p->link.next = flow; flow->hdr_len = hdr_len; if (hdr) memcpy(flow->hdr,hdr,hdr_len); else memcpy(flow->hdr,llc_oui_ip,sizeof(llc_oui_ip)); *arg = (unsigned long) flow; return 0; err_out: if (excess) atm_tc_put(sch,(unsigned long) excess); sockfd_put(sock); return error; } static int atm_tc_delete(struct Qdisc *sch,unsigned long arg) { struct atm_qdisc_data *p = PRIV(sch); struct atm_flow_data *flow = (struct atm_flow_data *) arg; DPRINTK("atm_tc_delete(sch %p,[qdisc %p],flow %p)\n",sch,p,flow); if (!find_flow(PRIV(sch),flow)) return -EINVAL; if (flow->filter_list || flow == &p->link) return -EBUSY; /* * Reference count must be 2: one for "keepalive" (set at class * creation), and one for the reference held when calling delete. */ if (flow->ref < 2) { printk(KERN_ERR "atm_tc_delete: flow->ref == %d\n",flow->ref); return -EINVAL; } if (flow->ref > 2) return -EBUSY; /* catch references via excess, etc.*/ atm_tc_put(sch,arg); return 0; } static void atm_tc_walk(struct Qdisc *sch,struct qdisc_walker *walker) { struct atm_qdisc_data *p = PRIV(sch); struct atm_flow_data *flow; DPRINTK("atm_tc_walk(sch %p,[qdisc %p],walker %p)\n",sch,p,walker); if (walker->stop) return; for (flow = p->flows; flow; flow = flow->next) { if (walker->count >= walker->skip) if (walker->fn(sch,(unsigned long) flow,walker) < 0) { walker->stop = 1; break; } walker->count++; } } static struct tcf_proto **atm_tc_find_tcf(struct Qdisc *sch,unsigned long cl) { struct atm_qdisc_data *p = PRIV(sch); struct atm_flow_data *flow = (struct atm_flow_data *) cl; DPRINTK("atm_tc_find_tcf(sch %p,[qdisc %p],flow %p)\n",sch,p,flow); return flow ? &flow->filter_list : &p->link.filter_list; } /* --------------------------- Qdisc operations ---------------------------- */ static int atm_tc_enqueue(struct sk_buff *skb,struct Qdisc *sch) { struct atm_qdisc_data *p = PRIV(sch); struct atm_flow_data *flow = NULL ; /* @@@ */ struct tcf_result res; int result; int ret = NET_XMIT_POLICED; D2PRINTK("atm_tc_enqueue(skb %p,sch %p,[qdisc %p])\n",skb,sch,p); result = TC_POLICE_OK; /* be nice to gcc */ if (TC_H_MAJ(skb->priority) != sch->handle || !(flow = (struct atm_flow_data *) atm_tc_get(sch,skb->priority))) for (flow = p->flows; flow; flow = flow->next) if (flow->filter_list) { result = tc_classify(skb,flow->filter_list, &res); if (result < 0) continue; flow = (struct atm_flow_data *) res.class; if (!flow) flow = lookup_flow(sch,res.classid); break; } if (!flow) flow = &p->link; else { if (flow->vcc) ATM_SKB(skb)->atm_options = flow->vcc->atm_options; /*@@@ looks good ... but it's not supposed to work :-)*/ #ifdef CONFIG_NET_CLS_POLICE switch (result) { case TC_POLICE_SHOT: kfree_skb(skb); break; case TC_POLICE_RECLASSIFY: if (flow->excess) flow = flow->excess; else { ATM_SKB(skb)->atm_options |= ATM_ATMOPT_CLP; break; } /* fall through */ case TC_POLICE_OK: /* fall through */ default: break; } #endif } if ( #ifdef CONFIG_NET_CLS_POLICE result == TC_POLICE_SHOT || #endif (ret = flow->q->enqueue(skb,flow->q)) != 0) { sch->stats.drops++; if (flow) flow->stats.drops++; return ret; } sch->stats.bytes += skb->len; sch->stats.packets++; flow->stats.bytes += skb->len; flow->stats.packets++; /* * Okay, this may seem weird. We pretend we've dropped the packet if * it goes via ATM. The reason for this is that the outer qdisc * expects to be able to q->dequeue the packet later on if we return * success at this place. Also, sch->q.qdisc needs to reflect whether * there is a packet egligible for dequeuing or not. Note that the * statistics of the outer qdisc are necessarily wrong because of all * this. There's currently no correct solution for this. */ if (flow == &p->link) { sch->q.qlen++; return 0; } tasklet_schedule(&p->task); return NET_XMIT_BYPASS; } /* * Dequeue packets and send them over ATM. Note that we quite deliberately * avoid checking net_device's flow control here, simply because sch_atm * uses its own channels, which have nothing to do with any CLIP/LANE/or * non-ATM interfaces. */ static void sch_atm_dequeue(unsigned long data) { struct Qdisc *sch = (struct Qdisc *) data; struct atm_qdisc_data *p = PRIV(sch); struct atm_flow_data *flow; struct sk_buff *skb; D2PRINTK("sch_atm_dequeue(sch %p,[qdisc %p])\n",sch,p); for (flow = p->link.next; flow; flow = flow->next) /* * If traffic is properly shaped, this won't generate nasty * little bursts. Otherwise, it may ... (but that's okay) */ while ((skb = flow->q->dequeue(flow->q))) { if (!atm_may_send(flow->vcc,skb->truesize)) { (void) flow->q->ops->requeue(skb,flow->q); break; } D2PRINTK("atm_tc_dequeue: sending on class %p\n",flow); /* remove any LL header somebody else has attached */ skb_pull(skb,(char *) skb->nh.iph-(char *) skb->data); if (skb_headroom(skb) < flow->hdr_len) { struct sk_buff *new; new = skb_realloc_headroom(skb,flow->hdr_len); dev_kfree_skb(skb); if (!new) continue; skb = new; } D2PRINTK("sch_atm_dequeue: ip %p, data %p\n", skb->nh.iph,skb->data); ATM_SKB(skb)->vcc = flow->vcc; memcpy(skb_push(skb,flow->hdr_len),flow->hdr, flow->hdr_len); atomic_add(skb->truesize, &flow->vcc->sk->sk_wmem_alloc); /* atm.atm_options are already set by atm_tc_enqueue */ (void) flow->vcc->send(flow->vcc,skb); } } static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch) { struct atm_qdisc_data *p = PRIV(sch); struct sk_buff *skb; D2PRINTK("atm_tc_dequeue(sch %p,[qdisc %p])\n",sch,p); tasklet_schedule(&p->task); skb = p->link.q->dequeue(p->link.q); if (skb) sch->q.qlen--; return skb; } static int atm_tc_requeue(struct sk_buff *skb,struct Qdisc *sch) { struct atm_qdisc_data *p = PRIV(sch); int ret; D2PRINTK("atm_tc_requeue(skb %p,sch %p,[qdisc %p])\n",skb,sch,p); ret = p->link.q->ops->requeue(skb,p->link.q); if (!ret) sch->q.qlen++; else { sch->stats.drops++; p->link.stats.drops++; } return ret; } static unsigned int atm_tc_drop(struct Qdisc *sch) { struct atm_qdisc_data *p = PRIV(sch); struct atm_flow_data *flow; unsigned int len; DPRINTK("atm_tc_drop(sch %p,[qdisc %p])\n",sch,p); for (flow = p->flows; flow; flow = flow->next) if (flow->q->ops->drop && (len = flow->q->ops->drop(flow->q))) return len; return 0; } static int atm_tc_init(struct Qdisc *sch,struct rtattr *opt) { struct atm_qdisc_data *p = PRIV(sch); DPRINTK("atm_tc_init(sch %p,[qdisc %p],opt %p)\n",sch,p,opt); memset(p,0,sizeof(*p)); p->flows = &p->link; if(!(p->link.q = qdisc_create_dflt(sch->dev,&pfifo_qdisc_ops))) p->link.q = &noop_qdisc; DPRINTK("atm_tc_init: link (%p) qdisc %p\n",&p->link,p->link.q); p->link.filter_list = NULL; p->link.vcc = NULL; p->link.sock = NULL; p->link.classid = sch->handle; p->link.ref = 1; p->link.next = NULL; tasklet_init(&p->task,sch_atm_dequeue,(unsigned long) sch); return 0; } static void atm_tc_reset(struct Qdisc *sch) { struct atm_qdisc_data *p = PRIV(sch); struct atm_flow_data *flow; DPRINTK("atm_tc_reset(sch %p,[qdisc %p])\n",sch,p); for (flow = p->flows; flow; flow = flow->next) qdisc_reset(flow->q); sch->q.qlen = 0; } static void atm_tc_destroy(struct Qdisc *sch) { struct atm_qdisc_data *p = PRIV(sch); struct atm_flow_data *flow; DPRINTK("atm_tc_destroy(sch %p,[qdisc %p])\n",sch,p); /* races ? */ while ((flow = p->flows)) { destroy_filters(flow); if (flow->ref > 1) printk(KERN_ERR "atm_destroy: %p->ref = %d\n",flow, flow->ref); atm_tc_put(sch,(unsigned long) flow); if (p->flows == flow) { printk(KERN_ERR "atm_destroy: putting flow %p didn't " "kill it\n",flow); p->flows = flow->next; /* brute force */ break; } } tasklet_kill(&p->task); } static int atm_tc_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb, struct tcmsg *tcm) { struct atm_qdisc_data *p = PRIV(sch); struct atm_flow_data *flow = (struct atm_flow_data *) cl; unsigned char *b = skb->tail; struct rtattr *rta; DPRINTK("atm_tc_dump_class(sch %p,[qdisc %p],flow %p,skb %p,tcm %p)\n", sch,p,flow,skb,tcm); if (!find_flow(p,flow)) return -EINVAL; tcm->tcm_handle = flow->classid; rta = (struct rtattr *) b; RTA_PUT(skb,TCA_OPTIONS,0,NULL); RTA_PUT(skb,TCA_ATM_HDR,flow->hdr_len,flow->hdr); if (flow->vcc) { struct sockaddr_atmpvc pvc; int state; pvc.sap_family = AF_ATMPVC; pvc.sap_addr.itf = flow->vcc->dev ? flow->vcc->dev->number : -1; pvc.sap_addr.vpi = flow->vcc->vpi; pvc.sap_addr.vci = flow->vcc->vci; RTA_PUT(skb,TCA_ATM_ADDR,sizeof(pvc),&pvc); state = ATM_VF2VS(flow->vcc->flags); RTA_PUT(skb,TCA_ATM_STATE,sizeof(state),&state); } if (flow->excess) RTA_PUT(skb,TCA_ATM_EXCESS,sizeof(u32),&flow->classid); else { static u32 zero; RTA_PUT(skb,TCA_ATM_EXCESS,sizeof(zero),&zero); } rta->rta_len = skb->tail-b; return skb->len; rtattr_failure: skb_trim(skb,b-skb->data); return -1; } static int atm_tc_dump(struct Qdisc *sch, struct sk_buff *skb) { return 0; } static struct Qdisc_class_ops atm_class_ops = { .graft = atm_tc_graft, .leaf = atm_tc_leaf, .get = atm_tc_get, .put = atm_tc_put, .change = atm_tc_change, .delete = atm_tc_delete, .walk = atm_tc_walk, .tcf_chain = atm_tc_find_tcf, .bind_tcf = atm_tc_bind_filter, .unbind_tcf = atm_tc_put, .dump = atm_tc_dump_class, }; static struct Qdisc_ops atm_qdisc_ops = { .next = NULL, .cl_ops = &atm_class_ops, .id = "atm", .priv_size = sizeof(struct atm_qdisc_data), .enqueue = atm_tc_enqueue, .dequeue = atm_tc_dequeue, .requeue = atm_tc_requeue, .drop = atm_tc_drop, .init = atm_tc_init, .reset = atm_tc_reset, .destroy = atm_tc_destroy, .change = NULL, .dump = atm_tc_dump, .owner = THIS_MODULE, }; static int __init atm_init(void) { return register_qdisc(&atm_qdisc_ops); } static void __exit atm_exit(void) { unregister_qdisc(&atm_qdisc_ops); } module_init(atm_init) module_exit(atm_exit)