/* net/sched/sch_atm.c - ATM VC selection "queueing discipline" */ /* Written 1998-2000 by Werner Almesberger, EPFL ICA */ #include <linux/module.h> #include <linux/init.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/skbuff.h> #include <linux/atmdev.h> #include <linux/atmclip.h> #include <linux/rtnetlink.h> #include <linux/file.h> /* for fput */ #include <net/netlink.h> #include <net/pkt_sched.h> extern struct socket *sockfd_lookup(int fd, int *err); /* @@@ fix this */ /* * 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 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 gnet_stats_basic bstats; struct gnet_stats_queue qstats; 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; pr_debug("find_flow(qdisc %p,flow %p)\n", qdisc, flow); for (walk = qdisc->flows; walk; walk = walk->next) if (walk == flow) return 1; pr_debug("find_flow: not found\n"); return 0; } static inline struct atm_flow_data *lookup_flow(struct Qdisc *sch, u32 classid) { struct atm_qdisc_data *p = qdisc_priv(sch); struct atm_flow_data *flow; for (flow = p->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 = qdisc_priv(sch); struct atm_flow_data *flow = (struct atm_flow_data *)arg; pr_debug("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; pr_debug("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 __maybe_unused = qdisc_priv(sch); struct atm_flow_data *flow; pr_debug("atm_tc_get(sch %p,[qdisc %p],classid %x)\n", sch, p, classid); flow = lookup_flow(sch, classid); if (flow) flow->ref++; pr_debug("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); } /* * 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 = qdisc_priv(sch); struct atm_flow_data *flow = (struct atm_flow_data *)cl; struct atm_flow_data **prev; pr_debug("atm_tc_put(sch %p,[qdisc %p],flow %p)\n", sch, p, flow); if (--flow->ref) return; pr_debug("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; pr_debug("atm_tc_put: qdisc %p\n", flow->q); qdisc_destroy(flow->q); tcf_destroy_chain(flow->filter_list); if (flow->sock) { pr_debug("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; pr_debug("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 const struct nla_policy atm_policy[TCA_ATM_MAX + 1] = { [TCA_ATM_FD] = { .type = NLA_U32 }, [TCA_ATM_EXCESS] = { .type = NLA_U32 }, }; static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent, struct nlattr **tca, unsigned long *arg) { struct atm_qdisc_data *p = qdisc_priv(sch); struct atm_flow_data *flow = (struct atm_flow_data *)*arg; struct atm_flow_data *excess = NULL; struct nlattr *opt = tca[TCA_OPTIONS]; struct nlattr *tb[TCA_ATM_MAX + 1]; struct socket *sock; int fd, error, hdr_len; void *hdr; pr_debug("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) return -EINVAL; error = nla_parse_nested(tb, TCA_ATM_MAX, opt, atm_policy); if (error < 0) return error; if (!tb[TCA_ATM_FD]) return -EINVAL; fd = nla_get_u32(tb[TCA_ATM_FD]); pr_debug("atm_tc_change: fd %d\n", fd); if (tb[TCA_ATM_HDR]) { hdr_len = nla_len(tb[TCA_ATM_HDR]); hdr = nla_data(tb[TCA_ATM_HDR]); } else { hdr_len = RFC1483LLC_LEN; hdr = NULL; /* default LLC/SNAP for IP */ } if (!tb[TCA_ATM_EXCESS]) excess = NULL; else { excess = (struct atm_flow_data *) atm_tc_get(sch, nla_get_u32(tb[TCA_ATM_EXCESS])); if (!excess) return -ENOENT; } pr_debug("atm_tc_change: type %d, payload %d, hdr_len %d\n", opt->nla_type, nla_len(opt), hdr_len); sock = sockfd_lookup(fd, &error); if (!sock) return error; /* f_count++ */ pr_debug("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)) { pr_debug("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); cl = atm_tc_get(sch, classid); if (!cl) break; atm_tc_put(sch, cl); } } pr_debug("atm_tc_change: new id %x\n", classid); flow = kzalloc(sizeof(struct atm_flow_data) + hdr_len, GFP_KERNEL); pr_debug("atm_tc_change: flow %p\n", flow); if (!flow) { error = -ENOBUFS; goto err_out; } flow->filter_list = NULL; flow->q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, classid); if (!flow->q) flow->q = &noop_qdisc; pr_debug("atm_tc_change: qdisc %p\n", flow->q); flow->sock = sock; flow->vcc = ATM_SD(sock); /* speedup */ flow->vcc->user_back = flow; pr_debug("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 = qdisc_priv(sch); struct atm_flow_data *flow = (struct atm_flow_data *)arg; pr_debug("atm_tc_delete(sch %p,[qdisc %p],flow %p)\n", sch, p, flow); if (!find_flow(qdisc_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 = qdisc_priv(sch); struct atm_flow_data *flow; pr_debug("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 = qdisc_priv(sch); struct atm_flow_data *flow = (struct atm_flow_data *)cl; pr_debug("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 = qdisc_priv(sch); struct atm_flow_data *flow = NULL; /* @@@ */ struct tcf_result res; int result; int ret = NET_XMIT_POLICED; pr_debug("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_compat(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_ACT switch (result) { case TC_ACT_QUEUED: case TC_ACT_STOLEN: kfree_skb(skb); return NET_XMIT_SUCCESS; case TC_ACT_SHOT: kfree_skb(skb); goto drop; case TC_POLICE_RECLASSIFY: if (flow->excess) flow = flow->excess; else ATM_SKB(skb)->atm_options |= ATM_ATMOPT_CLP; break; } #endif } ret = flow->q->enqueue(skb, flow->q); if (ret != 0) { drop: __maybe_unused sch->qstats.drops++; if (flow) flow->qstats.drops++; return ret; } sch->bstats.bytes += skb->len; sch->bstats.packets++; flow->bstats.bytes += skb->len; flow->bstats.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 = qdisc_priv(sch); struct atm_flow_data *flow; struct sk_buff *skb; pr_debug("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; } pr_debug("atm_tc_dequeue: sending on class %p\n", flow); /* remove any LL header somebody else has attached */ skb_pull(skb, skb_network_offset(skb)); 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; } pr_debug("sch_atm_dequeue: ip %p, data %p\n", skb_network_header(skb), skb->data); ATM_SKB(skb)->vcc = flow->vcc; memcpy(skb_push(skb, flow->hdr_len), flow->hdr, flow->hdr_len); atomic_add(skb->truesize, &sk_atm(flow->vcc)->sk_wmem_alloc); /* atm.atm_options are already set by atm_tc_enqueue */ flow->vcc->send(flow->vcc, skb); } } static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch) { struct atm_qdisc_data *p = qdisc_priv(sch); struct sk_buff *skb; pr_debug("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 = qdisc_priv(sch); int ret; pr_debug("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++; sch->qstats.requeues++; } else { sch->qstats.drops++; p->link.qstats.drops++; } return ret; } static unsigned int atm_tc_drop(struct Qdisc *sch) { struct atm_qdisc_data *p = qdisc_priv(sch); struct atm_flow_data *flow; unsigned int len; pr_debug("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 nlattr *opt) { struct atm_qdisc_data *p = qdisc_priv(sch); pr_debug("atm_tc_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt); p->flows = &p->link; p->link.q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, sch->handle); if (!p->link.q) p->link.q = &noop_qdisc; pr_debug("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 = qdisc_priv(sch); struct atm_flow_data *flow; pr_debug("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 = qdisc_priv(sch); struct atm_flow_data *flow; pr_debug("atm_tc_destroy(sch %p,[qdisc %p])\n", sch, p); /* races ? */ while ((flow = p->flows)) { tcf_destroy_chain(flow->filter_list); flow->filter_list = NULL; 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 = qdisc_priv(sch); struct atm_flow_data *flow = (struct atm_flow_data *)cl; struct nlattr *nest; pr_debug("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; tcm->tcm_info = flow->q->handle; nest = nla_nest_start(skb, TCA_OPTIONS); if (nest == NULL) goto nla_put_failure; NLA_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; NLA_PUT(skb, TCA_ATM_ADDR, sizeof(pvc), &pvc); state = ATM_VF2VS(flow->vcc->flags); NLA_PUT_U32(skb, TCA_ATM_STATE, state); } if (flow->excess) NLA_PUT_U32(skb, TCA_ATM_EXCESS, flow->classid); else { NLA_PUT_U32(skb, TCA_ATM_EXCESS, 0); } nla_nest_end(skb, nest); return skb->len; nla_put_failure: nla_nest_cancel(skb, nest); return -1; } static int atm_tc_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d) { struct atm_flow_data *flow = (struct atm_flow_data *)arg; flow->qstats.qlen = flow->q->q.qlen; if (gnet_stats_copy_basic(d, &flow->bstats) < 0 || gnet_stats_copy_queue(d, &flow->qstats) < 0) return -1; return 0; } static int atm_tc_dump(struct Qdisc *sch, struct sk_buff *skb) { return 0; } static const 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, .dump_stats = atm_tc_dump_class_stats, }; static struct Qdisc_ops atm_qdisc_ops __read_mostly = { .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, .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) MODULE_LICENSE("GPL");