* Stanford Junior University
*/
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
-#include <linux/in.h>
-#include <linux/ip.h>
-#include <linux/tcp.h>
-#include <linux/udp.h>
-#include <linux/in6.h>
#include <asm/uaccess.h>
#include <linux/types.h>
-#include <net/checksum.h>
#include "forward.h"
#include "datapath.h"
+#include "openflow/nicira-ext.h"
+#include "dp_act.h"
+#include "nx_msg.h"
#include "chain.h"
#include "flow.h"
/* FIXME: do we need to use GFP_ATOMIC everywhere here? */
-static int make_writable(struct sk_buff **);
static struct sk_buff *retrieve_skb(uint32_t id);
static void discard_skb(uint32_t id);
-/* 'skb' was received on 'in_port', a physical switch port between 0 and
- * OFPP_MAX. Process it according to 'chain'. Returns 0 if successful, in
- * which case 'skb' is destroyed, or -ESRCH if there is no matching flow, in
- * which case 'skb' still belongs to the caller. */
+/* 'skb' was received on port 'p', which may be a physical switch port, the
+ * local port, or a null pointer. Process it according to 'chain'. Returns 0
+ * if successful, in which case 'skb' is destroyed, or -ESRCH if there is no
+ * matching flow, in which case 'skb' still belongs to the caller. */
int run_flow_through_tables(struct sw_chain *chain, struct sk_buff *skb,
- int in_port)
+ struct net_bridge_port *p)
{
+ /* Ethernet address used as the destination for STP frames. */
+ static const uint8_t stp_eth_addr[ETH_ALEN]
+ = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x01 };
struct sw_flow_key key;
struct sw_flow *flow;
- flow_extract(skb, in_port, &key);
+ if (flow_extract(skb, p ? p->port_no : OFPP_NONE, &key)
+ && (chain->dp->flags & OFPC_FRAG_MASK) == OFPC_FRAG_DROP) {
+ /* Drop fragment. */
+ kfree_skb(skb);
+ return 0;
+ }
+ if (p && p->config & (OFPPC_NO_RECV | OFPPC_NO_RECV_STP) &&
+ p->config & (compare_ether_addr(key.dl_dst, stp_eth_addr)
+ ? OFPPC_NO_RECV : OFPPC_NO_RECV_STP)) {
+ kfree_skb(skb);
+ return 0;
+ }
+
flow = chain_lookup(chain, &key);
if (likely(flow != NULL)) {
+ struct sw_flow_actions *sf_acts = rcu_dereference(flow->sf_acts);
flow_used(flow, skb);
execute_actions(chain->dp, skb, &key,
- flow->actions, flow->n_actions);
+ sf_acts->actions, sf_acts->actions_len, 0);
return 0;
} else {
return -ESRCH;
}
}
-/* 'skb' was received on 'in_port', a physical switch port between 0 and
- * OFPP_MAX. Process it according to 'chain', sending it up to the controller
- * if no flow matches. Takes ownership of 'skb'. */
-void fwd_port_input(struct sw_chain *chain, struct sk_buff *skb, int in_port)
+/* 'skb' was received on port 'p', which may be a physical switch port, the
+ * local port, or a null pointer. Process it according to 'chain', sending it
+ * up to the controller if no flow matches. Takes ownership of 'skb'. */
+void fwd_port_input(struct sw_chain *chain, struct sk_buff *skb,
+ struct net_bridge_port *p)
{
- if (run_flow_through_tables(chain, skb, in_port))
+ WARN_ON_ONCE(skb_shared(skb));
+ WARN_ON_ONCE(skb->destructor);
+ if (run_flow_through_tables(chain, skb, p))
dp_output_control(chain->dp, skb, fwd_save_skb(skb),
chain->dp->miss_send_len,
OFPR_NO_MATCH);
}
-static int do_output(struct datapath *dp, struct sk_buff *skb, size_t max_len,
- int out_port)
-{
- if (!skb)
- return -ENOMEM;
- return (likely(out_port != OFPP_CONTROLLER)
- ? dp_output_port(dp, skb, out_port)
- : dp_output_control(dp, skb, fwd_save_skb(skb),
- max_len, OFPR_ACTION));
-}
-
-void execute_actions(struct datapath *dp, struct sk_buff *skb,
- const struct sw_flow_key *key,
- const struct ofp_action *actions, int n_actions)
-{
- /* 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;
- size_t max_len=0; /* Initialze to make compiler happy */
- uint16_t eth_proto;
- int i;
-
- prev_port = -1;
- eth_proto = ntohs(key->dl_type);
-
- for (i = 0; i < n_actions; i++) {
- const struct ofp_action *a = &actions[i];
-
- if (prev_port != -1) {
- do_output(dp, skb_clone(skb, GFP_ATOMIC),
- max_len, prev_port);
- prev_port = -1;
- }
-
- if (likely(a->type == htons(OFPAT_OUTPUT))) {
- prev_port = ntohs(a->arg.output.port);
- max_len = ntohs(a->arg.output.max_len);
- } else {
- if (!make_writable(&skb)) {
- if (net_ratelimit())
- printk("make_writable failed\n");
- break;
- }
- skb = execute_setter(skb, eth_proto, key, a);
- if (!skb) {
- if (net_ratelimit())
- printk("execute_setter lost skb\n");
- return;
- }
- }
- }
- if (prev_port != -1)
- do_output(dp, skb, max_len, prev_port);
- else
- kfree_skb(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 void modify_nh(struct sk_buff *skb, uint16_t eth_proto,
- uint8_t nw_proto, const struct ofp_action *a)
-{
- if (eth_proto == ETH_P_IP) {
- struct iphdr *nh = ip_hdr(skb);
- uint32_t new, *field;
-
- new = a->arg.nw_addr;
-
- if (a->type == htons(OFPAT_SET_NW_SRC))
- field = &nh->saddr;
- else
- field = &nh->daddr;
-
- if (nw_proto == IPPROTO_TCP) {
- struct tcphdr *th = tcp_hdr(skb);
- update_csum(&th->check, skb, *field, new, 1);
- } else if (nw_proto == IPPROTO_UDP) {
- struct udphdr *th = udp_hdr(skb);
- update_csum(&th->check, skb, *field, new, 1);
- }
- update_csum(&nh->check, skb, *field, new, 0);
- *field = new;
- }
-}
-
-static void modify_th(struct sk_buff *skb, uint16_t eth_proto,
- uint8_t nw_proto, const struct ofp_action *a)
-{
- if (eth_proto == ETH_P_IP) {
- uint16_t new, *field;
-
- new = a->arg.tp;
-
- if (nw_proto == IPPROTO_TCP) {
- struct tcphdr *th = tcp_hdr(skb);
-
- if (a->type == htons(OFPAT_SET_TP_SRC))
- field = &th->source;
- else
- field = &th->dest;
-
- update_csum(&th->check, skb, *field, new, 1);
- *field = new;
- } else if (nw_proto == IPPROTO_UDP) {
- struct udphdr *th = udp_hdr(skb);
-
- if (a->type == htons(OFPAT_SET_TP_SRC))
- field = &th->source;
- else
- field = &th->dest;
-
- update_csum(&th->check, skb, *field, new, 1);
- *field = new;
- }
- }
-}
-
-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(struct sk_buff *skb,
- const struct sw_flow_key *key, const struct ofp_action *a)
+static int
+recv_hello(struct sw_chain *chain, const struct sender *sender,
+ const void *msg)
{
- uint16_t new_id = ntohs(a->arg.vlan_id);
-
- if (new_id != OFP_VLAN_NONE) {
- if (key->dl_vlan != htons(OFP_VLAN_NONE)) {
- /* Modify vlan id, but maintain other TCI values */
- struct vlan_ethhdr *vh = vlan_eth_hdr(skb);
- vh->h_vlan_TCI = (vh->h_vlan_TCI
- & ~(htons(VLAN_VID_MASK))) | a->arg.vlan_id;
- } else {
- /* Add vlan header */
-
- /* xxx The vlan_put_tag function, doesn't seem to work
- * xxx reliably when it attempts to use the hardware-accelerated
- * xxx version. We'll directly use the software version
- * xxx until the problem can be diagnosed.
- */
- skb = __vlan_put_tag(skb, new_id);
- }
- } else {
- /* Remove an existing vlan header if it exists */
- vlan_pull_tag(skb);
- }
-
- return skb;
-}
-
-struct sk_buff *execute_setter(struct sk_buff *skb, uint16_t eth_proto,
- const struct sw_flow_key *key, const struct ofp_action *a)
-{
- switch (ntohs(a->type)) {
- case OFPAT_SET_DL_VLAN:
- skb = modify_vlan(skb, key, a);
- break;
-
- case OFPAT_SET_DL_SRC: {
- struct ethhdr *eh = eth_hdr(skb);
- memcpy(eh->h_source, a->arg.dl_addr, sizeof eh->h_source);
- break;
- }
- case OFPAT_SET_DL_DST: {
- struct ethhdr *eh = eth_hdr(skb);
- memcpy(eh->h_dest, a->arg.dl_addr, sizeof eh->h_dest);
- break;
- }
-
- case OFPAT_SET_NW_SRC:
- case OFPAT_SET_NW_DST:
- modify_nh(skb, eth_proto, key->nw_proto, a);
- break;
-
- case OFPAT_SET_TP_SRC:
- case OFPAT_SET_TP_DST:
- modify_th(skb, eth_proto, key->nw_proto, a);
- break;
-
- default:
- if (net_ratelimit())
- printk("execute_setter: unknown action: %d\n", ntohs(a->type));
- }
-
- return skb;
+ return dp_send_hello(chain->dp, sender, msg);
}
static int
const void *msg)
{
const struct ofp_switch_config *osc = msg;
+ int flags;
+
+ flags = ntohs(osc->flags) & (OFPC_SEND_FLOW_EXP | OFPC_FRAG_MASK);
+ if ((flags & OFPC_FRAG_MASK) != OFPC_FRAG_NORMAL
+ && (flags & OFPC_FRAG_MASK) != OFPC_FRAG_DROP) {
+ flags = (flags & ~OFPC_FRAG_MASK) | OFPC_FRAG_DROP;
+ }
+ chain->dp->flags = flags;
- chain->dp->flags = ntohs(osc->flags);
chain->dp->miss_send_len = ntohs(osc->miss_send_len);
return 0;
{
const struct ofp_packet_out *opo = msg;
struct sk_buff *skb;
- struct vlan_ethhdr *mac;
- int nh_ofs;
+ uint16_t v_code;
+ struct sw_flow_key key;
+ size_t actions_len = ntohs(opo->actions_len);
+
+ if (actions_len > (ntohs(opo->header.length) - sizeof *opo)) {
+ if (net_ratelimit())
+ printk("message too short for number of actions\n");
+ return -EINVAL;
+ }
if (ntohl(opo->buffer_id) == (uint32_t) -1) {
- int data_len = ntohs(opo->header.length) - sizeof *opo;
+ int data_len = ntohs(opo->header.length) - sizeof *opo - actions_len;
/* FIXME: there is likely a way to reuse the data in msg. */
skb = alloc_skb(data_len, GFP_ATOMIC);
/* FIXME? We don't reserve NET_IP_ALIGN or NET_SKB_PAD since
* we're just transmitting this raw without examining anything
* at those layers. */
- memcpy(skb_put(skb, data_len), opo->u.data, data_len);
- dp_set_origin(chain->dp, ntohs(opo->in_port), skb);
-
- skb_set_mac_header(skb, 0);
- mac = vlan_eth_hdr(skb);
- if (likely(mac->h_vlan_proto != htons(ETH_P_8021Q)))
- nh_ofs = sizeof(struct ethhdr);
- else
- nh_ofs = sizeof(struct vlan_ethhdr);
- skb_set_network_header(skb, nh_ofs);
-
- dp_output_port(chain->dp, skb, ntohs(opo->out_port));
+ skb_put(skb, data_len);
+ skb_copy_to_linear_data(skb,
+ (uint8_t *)opo->actions + actions_len,
+ data_len);
+ skb_reset_mac_header(skb);
} else {
- struct sw_flow_key key;
- int n_acts;
-
skb = retrieve_skb(ntohl(opo->buffer_id));
if (!skb)
return -ESRCH;
- dp_set_origin(chain->dp, ntohs(opo->in_port), skb);
+ }
+
+ dp_set_origin(chain->dp, ntohs(opo->in_port), skb);
+
+ flow_extract(skb, ntohs(opo->in_port), &key);
- n_acts = (ntohs(opo->header.length) - sizeof *opo)
- / sizeof *opo->u.actions;
- flow_extract(skb, ntohs(opo->in_port), &key);
- execute_actions(chain->dp, skb, &key, opo->u.actions, n_acts);
+ v_code = validate_actions(chain->dp, &key, opo->actions, actions_len);
+ if (v_code != ACT_VALIDATION_OK) {
+ dp_send_error_msg(chain->dp, sender, OFPET_BAD_ACTION, v_code,
+ msg, ntohs(opo->header.length));
+ goto error;
}
+
+ execute_actions(chain->dp, skb, &key, opo->actions, actions_len, 1);
+
return 0;
+
+error:
+ kfree_skb(skb);
+ return -EINVAL;
}
static int
{
const struct ofp_port_mod *opm = msg;
- dp_update_port_flags(chain->dp, &opm->desc);
+ dp_update_port_flags(chain->dp, opm);
return 0;
}
}
static int
-add_flow(struct sw_chain *chain, const struct ofp_flow_mod *ofm)
+add_flow(struct sw_chain *chain, const struct sender *sender,
+ const struct ofp_flow_mod *ofm)
{
int error = -ENOMEM;
- int i;
- int n_acts;
+ uint16_t v_code;
struct sw_flow *flow;
-
-
- /* To prevent loops, make sure there's no action to send to the
- * OFP_TABLE virtual port.
- */
- n_acts = (ntohs(ofm->header.length) - sizeof *ofm) / sizeof *ofm->actions;
- for (i=0; i<n_acts; i++) {
- const struct ofp_action *a = &ofm->actions[i];
-
- if (a->type == htons(OFPAT_OUTPUT)
- && (a->arg.output.port == htons(OFPP_TABLE)
- || a->arg.output.port == htons(OFPP_NONE))) {
- /* xxx Send fancy new error message? */
- goto error;
- }
- }
+ size_t actions_len = ntohs(ofm->header.length) - sizeof *ofm;
/* Allocate memory. */
- flow = flow_alloc(n_acts, GFP_ATOMIC);
+ flow = flow_alloc(actions_len, GFP_ATOMIC);
if (flow == NULL)
goto error;
- /* Fill out flow. */
flow_extract_match(&flow->key, &ofm->match);
- flow->max_idle = ntohs(ofm->max_idle);
+
+ v_code = validate_actions(chain->dp, &flow->key, ofm->actions, actions_len);
+ if (v_code != ACT_VALIDATION_OK) {
+ dp_send_error_msg(chain->dp, sender, OFPET_BAD_ACTION, v_code,
+ ofm, ntohs(ofm->header.length));
+ goto error_free_flow;
+ }
+
+ /* Fill out flow. */
flow->priority = flow->key.wildcards ? ntohs(ofm->priority) : -1;
- flow->timeout = jiffies + flow->max_idle * HZ;
- flow->n_actions = n_acts;
+ flow->idle_timeout = ntohs(ofm->idle_timeout);
+ flow->hard_timeout = ntohs(ofm->hard_timeout);
+ flow->used = jiffies;
flow->init_time = jiffies;
flow->byte_count = 0;
flow->packet_count = 0;
spin_lock_init(&flow->lock);
- memcpy(flow->actions, ofm->actions, n_acts * sizeof *flow->actions);
+ memcpy(flow->sf_acts->actions, ofm->actions, actions_len);
/* Act. */
error = chain_insert(chain, flow);
- if (error)
+ if (error == -ENOBUFS) {
+ dp_send_error_msg(chain->dp, sender, OFPET_FLOW_MOD_FAILED,
+ OFPFMFC_ALL_TABLES_FULL, ofm, ntohs(ofm->header.length));
+ goto error_free_flow;
+ } else if (error)
goto error_free_flow;
error = 0;
if (ntohl(ofm->buffer_id) != (uint32_t) -1) {
if (skb) {
struct sw_flow_key key;
flow_used(flow, skb);
+ dp_set_origin(chain->dp, ntohs(ofm->match.in_port), skb);
flow_extract(skb, ntohs(ofm->match.in_port), &key);
- execute_actions(chain->dp, skb, &key,
- ofm->actions, n_acts);
+ execute_actions(chain->dp, skb, &key, ofm->actions, actions_len, 0);
}
else
error = -ESRCH;
return error;
}
+static int
+mod_flow(struct sw_chain *chain, const struct sender *sender,
+ const struct ofp_flow_mod *ofm)
+{
+ int error = -ENOMEM;
+ uint16_t v_code;
+ size_t actions_len;
+ struct sw_flow_key key;
+ uint16_t priority;
+ int strict;
+
+ flow_extract_match(&key, &ofm->match);
+
+ actions_len = ntohs(ofm->header.length) - sizeof *ofm;
+
+ v_code = validate_actions(chain->dp, &key, ofm->actions, actions_len);
+ if (v_code != ACT_VALIDATION_OK) {
+ dp_send_error_msg(chain->dp, sender, OFPET_BAD_ACTION, v_code,
+ ofm, ntohs(ofm->header.length));
+ goto error;
+ }
+
+ priority = key.wildcards ? ntohs(ofm->priority) : -1;
+ strict = (ofm->command == htons(OFPFC_MODIFY_STRICT)) ? 1 : 0;
+ chain_modify(chain, &key, priority, strict, ofm->actions, actions_len);
+
+ if (ntohl(ofm->buffer_id) != (uint32_t) -1) {
+ struct sk_buff *skb = retrieve_skb(ntohl(ofm->buffer_id));
+ if (skb) {
+ struct sw_flow_key skb_key;
+ flow_extract(skb, ntohs(ofm->match.in_port), &skb_key);
+ execute_actions(chain->dp, skb, &skb_key,
+ ofm->actions, actions_len, 0);
+ }
+ else
+ error = -ESRCH;
+ }
+ return error;
+
+error:
+ if (ntohl(ofm->buffer_id) != (uint32_t) -1)
+ discard_skb(ntohl(ofm->buffer_id));
+ return error;
+}
+
static int
recv_flow(struct sw_chain *chain, const struct sender *sender, const void *msg)
{
uint16_t command = ntohs(ofm->command);
if (command == OFPFC_ADD) {
- return add_flow(chain, ofm);
+ return add_flow(chain, sender, ofm);
+ } else if ((command == OFPFC_MODIFY) || (command == OFPFC_MODIFY_STRICT)) {
+ return mod_flow(chain, sender, ofm);
} else if (command == OFPFC_DELETE) {
struct sw_flow_key key;
flow_extract_match(&key, &ofm->match);
}
}
+static int
+recv_vendor(struct sw_chain *chain, const struct sender *sender,
+ const void *msg)
+{
+ const struct ofp_vendor_header *ovh = msg;
+
+ switch(ntohl(ovh->vendor))
+ {
+ case NX_VENDOR_ID:
+ return nx_recv_msg(chain, sender, msg);
+ default:
+ if (net_ratelimit())
+ printk("Uknown vendor: %#x\n", ntohl(ovh->vendor));
+ dp_send_error_msg(chain->dp, sender, OFPET_BAD_REQUEST,
+ OFPBRC_BAD_VENDOR, msg, ntohs(ovh->header.length));
+ return -EINVAL;
+ }
+}
+
/* 'msg', which is 'length' bytes long, was received across Netlink from
* 'sender'. Apply it to 'chain'. */
int
};
static const struct openflow_packet packets[] = {
+ [OFPT_HELLO] = {
+ sizeof (struct ofp_header),
+ recv_hello,
+ },
+ [OFPT_ECHO_REQUEST] = {
+ sizeof (struct ofp_header),
+ recv_echo_request,
+ },
+ [OFPT_ECHO_REPLY] = {
+ sizeof (struct ofp_header),
+ recv_echo_reply,
+ },
+ [OFPT_VENDOR] = {
+ sizeof (struct ofp_vendor_header),
+ recv_vendor,
+ },
[OFPT_FEATURES_REQUEST] = {
sizeof (struct ofp_header),
recv_features_request,
[OFPT_PORT_MOD] = {
sizeof (struct ofp_port_mod),
recv_port_mod,
- },
- [OFPT_ECHO_REQUEST] = {
- sizeof (struct ofp_header),
- recv_echo_request,
- },
- [OFPT_ECHO_REPLY] = {
- sizeof (struct ofp_header),
- recv_echo_reply,
- },
+ }
};
- const struct openflow_packet *pkt;
struct ofp_header *oh;
oh = (struct ofp_header *) msg;
- if (oh->version != OFP_VERSION || oh->type >= ARRAY_SIZE(packets)
- || ntohs(oh->length) > length)
+ if (oh->version != OFP_VERSION
+ && oh->type != OFPT_HELLO
+ && oh->type != OFPT_ERROR
+ && oh->type != OFPT_ECHO_REQUEST
+ && oh->type != OFPT_ECHO_REPLY
+ && oh->type != OFPT_VENDOR)
+ {
+ dp_send_error_msg(chain->dp, sender, OFPET_BAD_REQUEST,
+ OFPBRC_BAD_VERSION, msg, length);
return -EINVAL;
+ }
+ if (ntohs(oh->length) != length) {
+ if (net_ratelimit())
+ printk("received message length wrong: %d/%d\n",
+ ntohs(oh->length), length);
+ return -EINVAL;
+ }
- pkt = &packets[oh->type];
- if (!pkt->handler)
- return -ENOSYS;
- if (length < pkt->min_size)
- return -EFAULT;
-
- return pkt->handler(chain, sender, msg);
+ if (oh->type < ARRAY_SIZE(packets)) {
+ const struct openflow_packet *pkt = &packets[oh->type];
+ if (pkt->handler) {
+ if (length < pkt->min_size)
+ return -EFAULT;
+ return pkt->handler(chain, sender, msg);
+ }
+ }
+ dp_send_error_msg(chain->dp, sender, OFPET_BAD_REQUEST,
+ OFPBRC_BAD_TYPE, msg, length);
+ return -EINVAL;
}
/* Packet buffering. */
uint32_t fwd_save_skb(struct sk_buff *skb)
{
+ struct sk_buff *old_skb = NULL;
struct packet_buffer *p;
unsigned long int flags;
uint32_t id;
+ /* FIXME: Probably just need a skb_clone() here. */
+ skb = skb_copy(skb, GFP_ATOMIC);
+ if (!skb)
+ return -1;
+
spin_lock_irqsave(&buffer_lock, flags);
buffer_idx = (buffer_idx + 1) & PKT_BUFFER_MASK;
p = &buffers[buffer_idx];
* OVERWRITE_SECS old. */
if (time_before(jiffies, p->exp_jiffies)) {
spin_unlock_irqrestore(&buffer_lock, flags);
+ kfree_skb(skb);
return -1;
- } else
- kfree_skb(p->skb);
+ } else {
+ /* Defer kfree_skb() until interrupts re-enabled.
+ * FIXME: we only need to do that if it has a
+ * destructor, but it never should since we orphan
+ * sk_buffs on entry. */
+ old_skb = p->skb;
+ }
}
/* Don't use maximum cookie value since the all-bits-1 id is
* special. */
if (++p->cookie >= (1u << PKT_COOKIE_BITS) - 1)
p->cookie = 0;
- skb_get(skb);
p->skb = skb;
p->exp_jiffies = jiffies + OVERWRITE_JIFFIES;
id = buffer_idx | (p->cookie << PKT_BUFFER_BITS);
spin_unlock_irqrestore(&buffer_lock, flags);
+ if (old_skb)
+ kfree_skb(old_skb);
+
return id;
}
void fwd_discard_all(void)
{
- unsigned long int flags;
int i;
- spin_lock_irqsave(&buffer_lock, flags);
for (i = 0; i < N_PKT_BUFFERS; i++) {
- kfree_skb(buffers[i].skb);
+ struct sk_buff *skb;
+ unsigned long int flags;
+
+ /* Defer kfree_skb() until interrupts re-enabled. */
+ spin_lock_irqsave(&buffer_lock, flags);
+ skb = buffers[i].skb;
buffers[i].skb = NULL;
+ spin_unlock_irqrestore(&buffer_lock, flags);
+
+ kfree_skb(skb);
}
- spin_unlock_irqrestore(&buffer_lock, flags);
}
static void discard_skb(uint32_t id)
{
+ struct sk_buff *old_skb = NULL;
unsigned long int flags;
struct packet_buffer *p;
spin_lock_irqsave(&buffer_lock, flags);
p = &buffers[id & PKT_BUFFER_MASK];
if (p->cookie == id >> PKT_BUFFER_BITS) {
- kfree_skb(p->skb);
+ /* Defer kfree_skb() until interrupts re-enabled. */
+ old_skb = p->skb;
p->skb = NULL;
}
spin_unlock_irqrestore(&buffer_lock, flags);
+
+ if (old_skb)
+ kfree_skb(old_skb);
}
void fwd_exit(void)
{
fwd_discard_all();
}
-
-/* Utility functions. */
-
-/* Makes '*pskb' writable, possibly copying it and setting '*pskb' to point to
- * the copy.
- * Returns 1 if successful, 0 on failure. */
-static int
-make_writable(struct sk_buff **pskb)
-{
- /* Based on skb_make_writable() in net/netfilter/core.c. */
- struct sk_buff *nskb;
-
- /* Not exclusive use of packet? Must copy. */
- if (skb_shared(*pskb) || skb_cloned(*pskb))
- goto copy_skb;
-
- return pskb_may_pull(*pskb, 40); /* FIXME? */
-
-copy_skb:
- nskb = skb_copy(*pskb, GFP_ATOMIC);
- if (!nskb)
- return 0;
- BUG_ON(skb_is_nonlinear(nskb));
-
- /* Rest of kernel will get very unhappy if we pass it a
- suddenly-orphaned skbuff */
- if ((*pskb)->sk)
- skb_set_owner_w(nskb, (*pskb)->sk);
- kfree_skb(*pskb);
- *pskb = nskb;
- return 1;
-}