diff options
Diffstat (limited to 'net/sched/sch_atm.c')
| -rw-r--r-- | net/sched/sch_atm.c | 691 |
1 files changed, 691 insertions, 0 deletions
diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c new file mode 100644 index 00000000..e25e4906 --- /dev/null +++ b/net/sched/sch_atm.c @@ -0,0 +1,691 @@ +/* net/sched/sch_atm.c - ATM VC selection "queueing discipline" */ + +/* Written 1998-2000 by Werner Almesberger, EPFL ICA */ + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/interrupt.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_packed bstats; + struct gnet_stats_queue qstats; + struct list_head list; + 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 list_head flows; /* NB: "link" is also on this + list */ + struct tasklet_struct task; /* dequeue tasklet */ +}; + +/* ------------------------- Class/flow operations ------------------------- */ + +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; + + list_for_each_entry(flow, &p->flows, list) { + if (flow->classid == classid) + return flow; + } + return NULL; +} + +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 (list_empty(&flow->list)) + return -EINVAL; + if (!new) + new = &noop_qdisc; + *old = flow->q; + 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; + + 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"); + list_del_init(&flow->list); + 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 %ld\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 %ld\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; + } + } 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_queue, &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; + list_add(&flow->list, &p->link.list); + 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 (list_empty(&flow->list)) + 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) { + pr_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; + list_for_each_entry(flow, &p->flows, list) { + if (walker->count >= walker->skip && + 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; + 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 */ + flow = NULL; + if (TC_H_MAJ(skb->priority) != sch->handle || + !(flow = (struct atm_flow_data *)atm_tc_get(sch, skb->priority))) { + list_for_each_entry(flow, &p->flows, list) { + 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); + goto done; + } + } + flow = NULL; +done: + ; + } + 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 | __NET_XMIT_STOLEN; + 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 = qdisc_enqueue(skb, flow->q); + if (ret != NET_XMIT_SUCCESS) { +drop: __maybe_unused + if (net_xmit_drop_count(ret)) { + sch->qstats.drops++; + if (flow) + flow->qstats.drops++; + } + return ret; + } + qdisc_bstats_update(sch, skb); + bstats_update(&flow->bstats, skb); + /* + * 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 NET_XMIT_SUCCESS; + } + tasklet_schedule(&p->task); + return NET_XMIT_SUCCESS | __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); + list_for_each_entry(flow, &p->flows, list) { + if (flow == &p->link) + continue; + /* + * If traffic is properly shaped, this won't generate nasty + * little bursts. Otherwise, it may ... (but that's okay) + */ + while ((skb = flow->q->ops->peek(flow->q))) { + if (!atm_may_send(flow->vcc, skb->truesize)) + break; + + skb = qdisc_dequeue_peeked(flow->q); + if (unlikely(!skb)) + 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 = qdisc_dequeue_peeked(p->link.q); + if (skb) + sch->q.qlen--; + return skb; +} + +static struct sk_buff *atm_tc_peek(struct Qdisc *sch) +{ + struct atm_qdisc_data *p = qdisc_priv(sch); + + pr_debug("atm_tc_peek(sch %p,[qdisc %p])\n", sch, p); + + return p->link.q->ops->peek(p->link.q); +} + +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); + list_for_each_entry(flow, &p->flows, list) { + 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); + INIT_LIST_HEAD(&p->flows); + INIT_LIST_HEAD(&p->link.list); + list_add(&p->link.list, &p->flows); + p->link.q = qdisc_create_dflt(sch->dev_queue, + &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; + 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); + list_for_each_entry(flow, &p->flows, list) + 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, *tmp; + + pr_debug("atm_tc_destroy(sch %p,[qdisc %p])\n", sch, p); + list_for_each_entry(flow, &p->flows, list) + tcf_destroy_chain(&flow->filter_list); + + list_for_each_entry_safe(flow, tmp, &p->flows, list) { + if (flow->ref > 1) + pr_err("atm_destroy: %p->ref = %d\n", flow, flow->ref); + atm_tc_put(sch, (unsigned long)flow); + } + 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 (list_empty(&flow->list)) + 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, + .peek = atm_tc_peek, + .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"); |