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As etharp already sends packets from the queue asynchronously, also make it send packet submitted through etharp_output().

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etharp_output() now returns err_t.
etharp_query() now sends a packet directly if the IP address is stable.
This commit is contained in:
likewise 2004-05-05 18:28:42 +00:00
parent 015cb1a35d
commit 29df95c514
3 changed files with 153 additions and 170 deletions
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2
src/include/netif/etharp.h
View File

@ -98,7 +98,7 @@ void etharp_tmr(void);
void etharp_ip_input(struct netif *netif, struct pbuf *p);
void etharp_arp_input(struct netif *netif, struct eth_addr *ethaddr,
struct pbuf *p);
struct pbuf *etharp_output(struct netif *netif, struct ip_addr *ipaddr,
err_t etharp_output(struct netif *netif, struct ip_addr *ipaddr,
struct pbuf *q);
err_t etharp_query(struct netif *netif, struct ip_addr *ipaddr, struct pbuf *q);

260
src/netif/etharp.c
View File

@ -514,29 +514,33 @@ etharp_arp_input(struct netif *netif, struct eth_addr *ethaddr, struct pbuf *p)
*
* @return If non-NULL, a packet ready to be sent by caller.
*
* @return
* - ERR_BUF Could not make room for Ethernet header.
* - ERR_MEM Hardware address unknown, and no more ARP entries available
* to query for address or queue the packet.
* - ERR_RTE No route to destination (no gateway to external networks).
*/
struct pbuf *
err_t
etharp_output(struct netif *netif, struct ip_addr *ipaddr, struct pbuf *q)
{
struct eth_addr *dest, *srcaddr, mcastaddr;
struct eth_hdr *ethhdr;
s8_t i;
err_t result;
/* make room for Ethernet header */
/* make room for Ethernet header - should not fail*/
if (pbuf_header(q, sizeof(struct eth_hdr)) != 0) {
/* The pbuf_header() call shouldn't fail, and we'll just bail
out if it does.. */
/* bail out */
LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE | 2, ("etharp_output: could not allocate room for header.\n"));
LINK_STATS_INC(link.lenerr);
return NULL;
pbuf_free(q);
return ERR_BUF;
}
/* assume unresolved Ethernet address */
dest = NULL;
/* Construct Ethernet header. Start with looking up deciding which
MAC address to use as a destination address. Broadcasts and
multicasts are special, all other addresses are looked up in the
ARP table. */
/* Determine on destination hardware address. Broadcasts and multicasts
* are special, other IP addresses are looked up in the ARP table. */
/* destination IP address is an IP broadcast address? */
if (ip_addr_isany(ipaddr) || ip_addr_isbroadcast(ipaddr, netif)) {
@ -557,86 +561,67 @@ etharp_output(struct netif *netif, struct ip_addr *ipaddr, struct pbuf *q)
}
/* destination IP address is an IP unicast address */
else {
/* destination IP network address not on local network?
* IP layer wants us to forward to the default gateway */
/* outside local network? */
if (!ip_addr_maskcmp(ipaddr, &(netif->ip_addr), &(netif->netmask))) {
/* interface has default gateway? */
if (netif->gw.addr != 0)
{
/* route to default gateway IP address */
if (netif->gw.addr != 0) {
/* send to hardware address of default gateway IP address */
ipaddr = &(netif->gw);
}
/* no gateway available? */
else
{
/* IP destination address outside local network, but no gateway available */
/* { packet is discarded } */
return NULL;
/* no default gateway available? */
} else {
/* destination unreachable, discard packet */
pbuf_free(q);
return ERR_RTE;
}
}
/* Ethernet address for IP destination address is in ARP cache? */
for (i = 0; i < ARP_TABLE_SIZE; ++i) {
/* match found? */
if (arp_table[i].state == ETHARP_STATE_STABLE &&
ip_addr_cmp(ipaddr, &arp_table[i].ipaddr)) {
dest = &arp_table[i].ethaddr;
break;
}
}
/* could not find the destination Ethernet address in ARP cache? */
if (dest == NULL) {
/* ARP query for the IP address, submit this IP packet for queueing */
/* TODO: How do we handle netif->ipaddr == ipaddr? */
etharp_query(netif, ipaddr, q);
/* { packet was queued (ERR_OK), or discarded } */
/* return nothing */
return NULL;
}
/* destination Ethernet address resolved from ARP cache */
else
{
/* fallthrough */
}
}
result = etharp_query(netif, ipaddr, q);
} /* else unicast */
/* destination Ethernet address known */
if (dest != NULL) {
/* obtain source Ethernet address of the given interface */
srcaddr = (struct eth_addr *)netif->hwaddr;
/* A valid IP->MAC address mapping was found, fill in the
* Ethernet header for the outgoing packet */
ethhdr = q->payload;
for(i = 0; i < netif->hwaddr_len; i++) {
ethhdr->dest.addr[i] = dest->addr[i];
ethhdr->src.addr[i] = srcaddr->addr[i];
}
ethhdr->type = htons(ETHTYPE_IP);
/* return the outgoing packet */
return q;
/* send packet */
result = netif->linkoutput(netif, q);
}
/* never reached; here for safety */
return NULL;
pbuf_free(q);
return result;
}
/**
* Send an ARP request for the given IP address.
*
* Sends an ARP request for the given IP address, unless
* a request for this address is already pending. Optionally
* queues an outgoing packet on the resulting ARP entry.
* If the IP address was not yet in the cache, a pending ARP cache entry
* is added and an ARP request is sent for the given address. The packet
* is queued on this entry.
*
* If the IP address was already pending in the cache, a new ARP request
* is sent for the given address. The packet is queued on this entry.
*
* If the IP address was already stable in the cache, the packet is
* directly sent. An ARP request is sent out.
*
* @param netif The lwIP network interface where ipaddr
* must be queried for.
* @param ipaddr The IP address to be resolved.
* @param q If non-NULL, a pbuf that must be queued on the
* ARP entry for the ipaddr IP address.
*
* @return NULL.
* @param q If non-NULL, a pbuf that must be delivered to the IP address.
*
* @return
* - ERR_BUF Could not make room for Ethernet header.
* - ERR_MEM Hardware address unknown, and no more ARP entries available
* to query for address or queue the packet.
* - ERR_MEM Could not queue packet due to memory shortage.
* - ERR_RTE No route to destination (no gateway to external networks).
*
* @note Might be used in the future by manual IP configuration
* as well.
*
@ -645,39 +630,71 @@ etharp_output(struct netif *netif, struct ip_addr *ipaddr, struct pbuf *q)
*/
err_t etharp_query(struct netif *netif, struct ip_addr *ipaddr, struct pbuf *q)
{
struct eth_addr *srcaddr;
struct etharp_hdr *hdr;
struct pbuf *p;
err_t result = ERR_OK;
s8_t i;
u8_t perform_arp_request = 1;
/* prevent 'unused argument' compiler warning if ARP_QUEUEING == 0 */
(void)q;
srcaddr = (struct eth_addr *)netif->hwaddr;
/* bail out if this IP address is pending */
s8_t i; /* ARP entry index */
u8_t k; /* Ethernet address octet index */
/* Do three things in this order (by design):
*
* 1) send out ARP request
* 2) find entry in ARP cache
* 3) handle the packet
*/
/* allocate a pbuf for the outgoing ARP request packet */
p = pbuf_alloc(PBUF_LINK, sizeof(struct etharp_hdr), PBUF_RAM);
/* could allocate a pbuf for an ARP request? */
if (p != NULL) {
struct etharp_hdr *hdr = p->payload;
LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE, ("etharp_query: sending ARP request.\n"));
hdr->opcode = htons(ARP_REQUEST);
for (k = 0; k < netif->hwaddr_len; k++)
{
hdr->shwaddr.addr[k] = srcaddr->addr[k];
/* the hardware address is what we ask for, in
* a request it is a don't-care value, we use zeroes */
hdr->dhwaddr.addr[k] = 0x00;
}
hdr->dipaddr = *(struct ip_addr2 *)ipaddr;
hdr->sipaddr = *(struct ip_addr2 *)&netif->ip_addr;
hdr->hwtype = htons(HWTYPE_ETHERNET);
ARPH_HWLEN_SET(hdr, netif->hwaddr_len);
hdr->proto = htons(ETHTYPE_IP);
ARPH_PROTOLEN_SET(hdr, sizeof(struct ip_addr));
for (k = 0; k < netif->hwaddr_len; ++k)
{
/* broadcast to all network interfaces on the local network */
hdr->ethhdr.dest.addr[k] = 0xff;
hdr->ethhdr.src.addr[k] = srcaddr->addr[k];
}
hdr->ethhdr.type = htons(ETHTYPE_ARP);
/* send ARP query */
result = netif->linkoutput(netif, p);
/* free ARP query packet */
pbuf_free(p);
p = NULL;
/* could not allocate pbuf for ARP request */
} else {
result = ERR_MEM;
LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE | 2, ("etharp_query: could not allocate pbuf for ARP request.\n"));
}
/* search entry of queried IP address in the ARP cache */
for (i = 0; i < ARP_TABLE_SIZE; ++i) {
/* valid ARP cache entry with matching IP address? */
if (arp_table[i].state != ETHARP_STATE_EMPTY &&
ip_addr_cmp(ipaddr, &arp_table[i].ipaddr)) {
/* pending entry? */
if (arp_table[i].state == ETHARP_STATE_PENDING) {
LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE | DBG_STATE, ("etharp_query: requested IP already pending as entry %u\n", i));
/* break out of for-loop, user may wish to queue a packet on a pending entry */
/* TODO: we will issue a new ARP request, which should not occur too often */
/* we might want to run a faster timer on ARP to limit this */
LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE | DBG_STATE, ("etharp_query: requested IP already pending in entry %u\n", i));
/* { i != ARP_TABLE_SIZE } */
break;
}
/* stable entry? */
else if (arp_table[i].state == ETHARP_STATE_STABLE) {
LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE | DBG_STATE, ("etharp_query: requested IP already stable as entry %u\n", i));
/* User wishes to queue a packet on a stable entry (or does she want to send
* out the packet immediately, we will not know), so we force an ARP request.
* Upon response we will send out the queued packet in etharp_update().
*
* Alternatively, we could accept the stable entry, and just send out the packet
* immediately. I chose to implement the former approach.
*/
perform_arp_request = (q?1:0);
LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE | DBG_STATE, ("etharp_query: requested IP already stable in entry %u\n", i));
/* { i != ARP_TABLE_SIZE } */
break;
}
@ -696,56 +713,43 @@ err_t etharp_query(struct netif *netif, struct ip_addr *ipaddr, struct pbuf *q)
/* i is available, create ARP entry */
arp_table[i].state = ETHARP_STATE_PENDING;
ip_addr_set(&arp_table[i].ipaddr, ipaddr);
arp_table[i].p = NULL;
LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE, ("etharp_query: added pending entry %u for IP address\n", i));
}
/* { i is now valid } */
/* { i is either a (new or existing) PENDING or STABLE entry } */
/* packet given? */
if (q != NULL)
/* stable entry? */
if (arp_table[i].state == ETHARP_STATE_STABLE) {
/* we have a valid IP->Ethernet address mapping,
* fill in the Ethernet header for the outgoing packet */
struct eth_addr * srcaddr = (struct eth_addr *)netif->hwaddr;
struct eth_hdr *ethhdr = q->payload;
for(k = 0; k < netif->hwaddr_len; k++) {
ethhdr->dest.addr[k] = arp_table[i].ethaddr.addr[k];
ethhdr->src.addr[k] = srcaddr->addr[k];
}
ethhdr->type = htons(ETHTYPE_IP);
LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE, ("etharp_query: sending packet %p\n", (void *)q));
/* send the packet */
result = netif->linkoutput(netif, q);
#if ARP_QUEUEING /* queue the given q packet */
/* copy any PBUF_REF referenced payloads into PBUF_RAM */
/* (the caller assumes the referenced payload can be freed) */
q = pbuf_take(q);
/* queue packet (even on a stable entry, see above) */
pbuf_queue(arp_table[i].p, q);
/* pending entry? (either just created or already pending */
} else if (arp_table[i].state == ETHARP_STATE_PENDING) {
/* copy any PBUF_REF referenced payloads into PBUF_RAM */
/* (the caller assumes the referenced payload can be freed) */
p = pbuf_take(q);
/* queue packet */
if (p != NULL) {
pbuf_queue(arp_table[i].p, p);
LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE, ("etharp_query: queued packet %p on ARP entry %d\n", (void *)q, i));
} else {
LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE, ("etharp_query: could not queue a copy of PBUF_REF packet %p (out of memory)\n", (void *)q));
result = ERR_MEM;
}
#endif
/* ARP request? */
if (perform_arp_request)
{
struct pbuf *p;
/* allocate a pbuf for the outgoing ARP request packet */
p = pbuf_alloc(PBUF_LINK, sizeof(struct etharp_hdr), PBUF_RAM);
/* could allocate pbuf? */
if (p != NULL) {
u8_t j;
LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE, ("etharp_query: sending ARP request.\n"));
hdr = p->payload;
hdr->opcode = htons(ARP_REQUEST);
for (j = 0; j < netif->hwaddr_len; ++j)
{
hdr->shwaddr.addr[j] = srcaddr->addr[j];
/* the hardware address is what we ask for, in
* a request it is a don't-care, we use 0's */
hdr->dhwaddr.addr[j] = 0x00;
}
hdr->dipaddr = *(struct ip_addr2 *)ipaddr;
hdr->sipaddr = *(struct ip_addr2 *)&netif->ip_addr;
hdr->hwtype = htons(HWTYPE_ETHERNET);
ARPH_HWLEN_SET(hdr, netif->hwaddr_len);
hdr->proto = htons(ETHTYPE_IP);
ARPH_PROTOLEN_SET(hdr, sizeof(struct ip_addr));
for (j = 0; j < netif->hwaddr_len; ++j)
{
hdr->ethhdr.dest.addr[j] = 0xff;
hdr->ethhdr.src.addr[j] = srcaddr->addr[j];
}
hdr->ethhdr.type = htons(ETHTYPE_ARP);
/* send ARP query */
result = netif->linkoutput(netif, p);
/* free ARP query packet */
pbuf_free(p);
p = NULL;
} else {
result = ERR_MEM;
LWIP_DEBUGF(ETHARP_DEBUG | DBG_TRACE | 2, ("etharp_query: could not allocate pbuf for ARP request.\n"));
}
}
return result;

61
src/netif/ethernetif.c
View File

@ -61,7 +61,6 @@ static void ethernetif_input(struct netif *netif);
static err_t ethernetif_output(struct netif *netif, struct pbuf *p,
struct ip_addr *ipaddr);
static void
low_level_init(struct netif *netif)
{
@ -95,7 +94,6 @@ low_level_init(struct netif *netif)
*
*/
static err_t
low_level_output(struct ethernetif *ethernetif, struct pbuf *p)
{
@ -199,30 +197,10 @@ static err_t
ethernetif_output(struct netif *netif, struct pbuf *p,
struct ip_addr *ipaddr)
{
struct ethernetif *ethernetif;
struct pbuf *q;
struct eth_hdr *ethhdr;
struct eth_addr *dest, mcastaddr;
struct ip_addr *queryaddr;
err_t err;
u8_t i;
ethernetif = netif->state;
/* resolve the link destination hardware address */
p = etharp_output(netif, ipaddr, p);
/* network hardware address obtained? */
if (p == NULL)
{
/* we cannot tell if the packet was sent: the packet could */
/* have been queued on an ARP entry that was already pending. */
return ERR_OK;
}
/* send out the packet */
return low_level_output(ethernetif, p);
/* resolve hardware address, then send (or queue) packet */
return etharp_output(netif, ipaddr, p);
}
/*
@ -240,42 +218,43 @@ ethernetif_input(struct netif *netif)
{
struct ethernetif *ethernetif;
struct eth_hdr *ethhdr;
struct pbuf *p, *q;
struct pbuf *p;
ethernetif = netif->state;
/* move received packet into a new pbuf */
p = low_level_input(ethernetif);
if (p != NULL)
return;
/* no packet could be read, silently ignore this */
if (p == NULL) return;
/* points to packet payload, which starts with an Ethernet header */
ethhdr = p->payload;
#ifdef LINK_STATS
lwip_stats.link.recv++;
#endif /* LINK_STATS */
ethhdr = p->payload;
q = NULL;
switch (htons(ethhdr->type)) {
case ETHTYPE_IP:
q = etharp_ip_input(netif, p);
pbuf_header(p, -sizeof(struct eth_hdr));
netif->input(p, netif);
break;
/* IP packet? */
case ETHTYPE_IP:
/* update ARP table */
etharp_ip_input(netif, p);
/* skip Ethernet header */
pbuf_header(p, -sizeof(struct eth_hdr));
/* pass to network layer */
netif->input(p, netif);
break;
case ETHTYPE_ARP:
q = etharp_arp_input(netif, ethernetif->ethaddr, p);
/* pass p to ARP module */
etharp_arp_input(netif, ethernetif->ethaddr, p);
break;
default:
pbuf_free(p);
p = NULL;
break;
}
if (q != NULL) {
low_level_output(ethernetif, q);
pbuf_free(q);
q = NULL;
}
}
static void