From 064af42167bf4fc9aaea2702d80ce08074b889c0 Mon Sep 17 00:00:00 2001 From: Ben Pfaff Date: Wed, 8 Jul 2009 13:19:16 -0700 Subject: Import from old repository commit 61ef2b42a9c4ba8e1600f15bb0236765edc2ad45. --- datapath/actions.c | 421 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 421 insertions(+) create mode 100644 datapath/actions.c (limited to 'datapath/actions.c') diff --git a/datapath/actions.c b/datapath/actions.c new file mode 100644 index 00000000..30b840cb --- /dev/null +++ b/datapath/actions.c @@ -0,0 +1,421 @@ +/* + * Distributed under the terms of the GNU GPL version 2. + * Copyright (c) 2007, 2008, 2009 Nicira Networks. + */ + +/* Functions for executing flow actions. */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "datapath.h" +#include "dp_dev.h" +#include "actions.h" +#include "openvswitch/datapath-protocol.h" + +struct sk_buff * +make_writable(struct sk_buff *skb, gfp_t gfp) +{ + if (skb_shared(skb) || skb_cloned(skb)) { + struct sk_buff *nskb = skb_copy(skb, gfp); + if (nskb) { + kfree_skb(skb); + return nskb; + } + } else { + unsigned int hdr_len = (skb_transport_offset(skb) + + sizeof(struct tcphdr)); + if (pskb_may_pull(skb, min(hdr_len, skb->len))) + return skb; + } + kfree_skb(skb); + return NULL; +} + + +static struct sk_buff * +vlan_pull_tag(struct sk_buff *skb) +{ + struct vlan_ethhdr *vh = vlan_eth_hdr(skb); + struct ethhdr *eh; + + + /* Verify we were given a vlan packet */ + if (vh->h_vlan_proto != htons(ETH_P_8021Q)) + return skb; + + memmove(skb->data + VLAN_HLEN, skb->data, 2 * VLAN_ETH_ALEN); + + eh = (struct ethhdr *)skb_pull(skb, VLAN_HLEN); + + skb->protocol = eh->h_proto; + skb->mac_header += VLAN_HLEN; + + return skb; +} + + +static struct sk_buff * +modify_vlan_tci(struct datapath *dp, struct sk_buff *skb, + struct odp_flow_key *key, const union odp_action *a, + int n_actions, gfp_t gfp) +{ + u16 tci, mask; + + if (a->type == ODPAT_SET_VLAN_VID) { + tci = ntohs(a->vlan_vid.vlan_vid); + mask = VLAN_VID_MASK; + key->dl_vlan = htons(tci & mask); + } else { + tci = a->vlan_pcp.vlan_pcp << 13; + mask = VLAN_PCP_MASK; + } + + skb = make_writable(skb, gfp); + if (!skb) + return ERR_PTR(-ENOMEM); + + if (skb->protocol == htons(ETH_P_8021Q)) { + /* Modify vlan id, but maintain other TCI values */ + struct vlan_ethhdr *vh = vlan_eth_hdr(skb); + vh->h_vlan_TCI = htons((ntohs(vh->h_vlan_TCI) & ~mask) | tci); + } else { + /* Add vlan header */ + + /* Set up checksumming pointers for checksum-deferred packets + * on Xen. Otherwise, dev_queue_xmit() will try to do this + * when we send the packet out on the wire, and it will fail at + * that point because skb_checksum_setup() will not look inside + * an 802.1Q header. */ + skb_checksum_setup(skb); + + /* GSO is not implemented for packets with an 802.1Q header, so + * we have to do segmentation before we add that header. + * + * GSO does work with hardware-accelerated VLAN tagging, but we + * can't use hardware-accelerated VLAN tagging since it + * requires the device to have a VLAN group configured (with + * e.g. vconfig(8)) and we don't do that. + * + * Having to do this here may be a performance loss, since we + * can't take advantage of TSO hardware support, although it + * does not make a measurable network performance difference + * for 1G Ethernet. Fixing that would require patching the + * kernel (either to add GSO support to the VLAN protocol or to + * support hardware-accelerated VLAN tagging without VLAN + * groups configured). */ + if (skb_is_gso(skb)) { + struct sk_buff *segs; + + segs = skb_gso_segment(skb, 0); + kfree_skb(skb); + if (unlikely(IS_ERR(segs))) + return ERR_CAST(segs); + + do { + struct sk_buff *nskb = segs->next; + int err; + + segs->next = NULL; + + segs = __vlan_put_tag(segs, tci); + err = -ENOMEM; + if (segs) { + struct odp_flow_key segkey = *key; + err = execute_actions(dp, segs, + &segkey, a + 1, + n_actions - 1, + gfp); + } + + if (unlikely(err)) { + while ((segs = nskb)) { + nskb = segs->next; + segs->next = NULL; + kfree_skb(segs); + } + return ERR_PTR(err); + } + + segs = nskb; + } while (segs->next); + + skb = segs; + } + + /* The hardware-accelerated version of vlan_put_tag() works + * only for a device that has a VLAN group configured (with + * e.g. vconfig(8)), so call the software-only version + * __vlan_put_tag() directly instead. + */ + skb = __vlan_put_tag(skb, tci); + if (!skb) + return ERR_PTR(-ENOMEM); + } + + return skb; +} + +static struct sk_buff *strip_vlan(struct sk_buff *skb, + struct odp_flow_key *key, gfp_t gfp) +{ + skb = make_writable(skb, gfp); + if (skb) { + vlan_pull_tag(skb); + key->dl_vlan = htons(ODP_VLAN_NONE); + } + return skb; +} + +static struct sk_buff *set_dl_addr(struct sk_buff *skb, + const struct odp_action_dl_addr *a, + gfp_t gfp) +{ + skb = make_writable(skb, gfp); + if (skb) { + struct ethhdr *eh = eth_hdr(skb); + memcpy(a->type == ODPAT_SET_DL_SRC ? eh->h_source : eh->h_dest, + a->dl_addr, ETH_ALEN); + } + return skb; +} + +/* Updates 'sum', which is a field in 'skb''s data, given that a 4-byte field + * covered by the sum has been changed from 'from' to 'to'. If set, + * 'pseudohdr' indicates that the field is in the TCP or UDP pseudo-header. + * Based on nf_proto_csum_replace4. */ +static void update_csum(__sum16 *sum, struct sk_buff *skb, + __be32 from, __be32 to, int pseudohdr) +{ + __be32 diff[] = { ~from, to }; + if (skb->ip_summed != CHECKSUM_PARTIAL) { + *sum = csum_fold(csum_partial((char *)diff, sizeof(diff), + ~csum_unfold(*sum))); + if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr) + skb->csum = ~csum_partial((char *)diff, sizeof(diff), + ~skb->csum); + } else if (pseudohdr) + *sum = ~csum_fold(csum_partial((char *)diff, sizeof(diff), + csum_unfold(*sum))); +} + +static struct sk_buff *set_nw_addr(struct sk_buff *skb, + struct odp_flow_key *key, + const struct odp_action_nw_addr *a, + gfp_t gfp) +{ + if (key->dl_type != htons(ETH_P_IP)) + return skb; + + skb = make_writable(skb, gfp); + if (skb) { + struct iphdr *nh = ip_hdr(skb); + u32 *f = a->type == ODPAT_SET_NW_SRC ? &nh->saddr : &nh->daddr; + u32 old = *f; + u32 new = a->nw_addr; + + if (key->nw_proto == IPPROTO_TCP) { + struct tcphdr *th = tcp_hdr(skb); + update_csum(&th->check, skb, old, new, 1); + } else if (key->nw_proto == IPPROTO_UDP) { + struct udphdr *th = udp_hdr(skb); + update_csum(&th->check, skb, old, new, 1); + } + update_csum(&nh->check, skb, old, new, 0); + *f = new; + } + return skb; +} + +static struct sk_buff * +set_tp_port(struct sk_buff *skb, struct odp_flow_key *key, + const struct odp_action_tp_port *a, + gfp_t gfp) +{ + int check_ofs; + + if (key->dl_type != htons(ETH_P_IP)) + return skb; + + if (key->nw_proto == IPPROTO_TCP) + check_ofs = offsetof(struct tcphdr, check); + else if (key->nw_proto == IPPROTO_UDP) + check_ofs = offsetof(struct udphdr, check); + else + return skb; + + skb = make_writable(skb, gfp); + if (skb) { + struct udphdr *th = udp_hdr(skb); + u16 *f = a->type == ODPAT_SET_TP_SRC ? &th->source : &th->dest; + u16 old = *f; + u16 new = a->tp_port; + update_csum((u16*)((u8*)skb->data + check_ofs), + skb, old, new, 1); + *f = new; + } + return skb; +} + +static inline unsigned packet_length(const struct sk_buff *skb) +{ + unsigned length = skb->len - ETH_HLEN; + if (skb->protocol == htons(ETH_P_8021Q)) + length -= VLAN_HLEN; + return length; +} + +int dp_xmit_skb(struct sk_buff *skb) +{ + struct datapath *dp = skb->dev->br_port->dp; + int len = skb->len; + + if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb)) { + printk(KERN_WARNING "%s: dropped over-mtu packet: %d > %d\n", + dp_name(dp), packet_length(skb), skb->dev->mtu); + kfree_skb(skb); + return -E2BIG; + } + + dev_queue_xmit(skb); + + return len; +} + +static void +do_output(struct datapath *dp, struct sk_buff *skb, int out_port) +{ + struct net_bridge_port *p; + struct net_device *dev; + + if (!skb) + goto error; + + p = dp->ports[out_port]; + if (!p) + goto error; + + dev = skb->dev = p->dev; + if (is_dp_dev(dev)) + dp_dev_recv(dev, skb); + else + dp_xmit_skb(skb); + return; + +error: + kfree_skb(skb); +} + +/* Never consumes 'skb'. Returns a port that 'skb' should be sent to, -1 if + * none. */ +static int output_group(struct datapath *dp, __u16 group, + struct sk_buff *skb, gfp_t gfp) +{ + struct dp_port_group *g = rcu_dereference(dp->groups[group]); + int prev_port = -1; + int i; + + if (!g) + return -1; + for (i = 0; i < g->n_ports; i++) { + struct net_bridge_port *p = dp->ports[g->ports[i]]; + if (!p || skb->dev == p->dev) + continue; + if (prev_port != -1) { + struct sk_buff *clone = skb_clone(skb, gfp); + if (!clone) + return -1; + do_output(dp, clone, prev_port); + } + prev_port = p->port_no; + } + return prev_port; +} + +static int +output_control(struct datapath *dp, struct sk_buff *skb, u32 arg, gfp_t gfp) +{ + skb = skb_clone(skb, gfp); + if (!skb) + return -ENOMEM; + return dp_output_control(dp, skb, _ODPL_ACTION_NR, arg); +} + +/* Execute a list of actions against 'skb'. */ +int execute_actions(struct datapath *dp, struct sk_buff *skb, + struct odp_flow_key *key, + const union odp_action *a, int n_actions, + gfp_t gfp) +{ + /* Every output action needs a separate clone of 'skb', but the common + * case is just a single output action, so that doing a clone and + * then freeing the original skbuff is wasteful. So the following code + * is slightly obscure just to avoid that. */ + int prev_port = -1; + int err = 0; + for (; n_actions > 0; a++, n_actions--) { + WARN_ON_ONCE(skb_shared(skb)); + if (prev_port != -1) { + do_output(dp, skb_clone(skb, gfp), prev_port); + prev_port = -1; + } + + switch (a->type) { + case ODPAT_OUTPUT: + prev_port = a->output.port; + break; + + case ODPAT_OUTPUT_GROUP: + prev_port = output_group(dp, a->output_group.group, + skb, gfp); + break; + + case ODPAT_CONTROLLER: + err = output_control(dp, skb, a->controller.arg, gfp); + if (err) { + kfree_skb(skb); + return err; + } + break; + + case ODPAT_SET_VLAN_VID: + case ODPAT_SET_VLAN_PCP: + skb = modify_vlan_tci(dp, skb, key, a, n_actions, gfp); + if (IS_ERR(skb)) + return PTR_ERR(skb); + break; + + case ODPAT_STRIP_VLAN: + skb = strip_vlan(skb, key, gfp); + break; + + case ODPAT_SET_DL_SRC: + case ODPAT_SET_DL_DST: + skb = set_dl_addr(skb, &a->dl_addr, gfp); + break; + + case ODPAT_SET_NW_SRC: + case ODPAT_SET_NW_DST: + skb = set_nw_addr(skb, key, &a->nw_addr, gfp); + break; + + case ODPAT_SET_TP_SRC: + case ODPAT_SET_TP_DST: + skb = set_tp_port(skb, key, &a->tp_port, gfp); + break; + } + if (!skb) + return -ENOMEM; + } + if (prev_port != -1) + do_output(dp, skb, prev_port); + else + kfree_skb(skb); + return err; +} -- cgit v1.2.3