Skip to content

Remove packet copy when transmitting CSP packets #33

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
troelsjessen wants to merge 1 commit into
base: master
Choose a base branch
from
+77 −71
Open

Remove packet copy when transmitting CSP packets #33

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
148 changes: 77 additions & 71 deletions src/csp_io.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -84,63 +84,84 @@ void csp_id_clear(csp_id_t * target) {
target->flags = 0;
}

static int is_same_subnet(csp_iface_t * iface, csp_iface_t * routed_from) {

/* This check is is similar to that below, but faster */
if (iface == routed_from) {
return 1;
}

/* Do not send to interface with similar subnet (split horizon) */
if (csp_iflist_is_within_subnet(iface->addr, routed_from)) {
return 1;
}

return 0;
}

static void convert_broadcast(csp_id_t * idout, csp_id_t * idout_copy, csp_iface_t * snd_iface) {

/* Rewrite routed brodcast (L3) to local (L2) when arriving at the interface */
if (csp_id_is_broadcast(idout->dst, snd_iface)) {
idout_copy->dst = csp_id_get_max_nodeid();
}
}

static void send_packet(csp_id_t * idout_copy, csp_packet_t * snd_pkt, csp_iface_t * snd_iface, uint16_t via, int from_me) {

/* Apply outgoing interface address to packet */
if ((from_me) && (idout_copy->src == 0)) {
idout_copy->src = snd_iface->addr;
}

if (snd_pkt != NULL) {
csp_send_direct_iface(idout_copy, snd_pkt, snd_iface, via, from_me);
}
}

void csp_send_direct(csp_id_t* idout, csp_packet_t * packet, csp_iface_t * routed_from) {

int from_me = (routed_from == NULL ? 1 : 0);

/* Try to find the destination on any local subnets */
int via = CSP_NO_VIA_ADDRESS;
csp_iface_t * iface = NULL;
csp_packet_t * copy = NULL;
int local_found = 0;

/* Quickly send on loopback */
if(idout->dst == csp_if_lo.addr){
if (idout->dst == csp_if_lo.addr) {
csp_send_direct_iface(idout, packet, &csp_if_lo, via, from_me);
return;
}

/* Make copy as broadcast modifies destination making iflist_get_by_subnet the skip next redundant ifaces */
csp_id_t _idout = *idout;
csp_id_t idout_copy = *idout; /* Broadcast function procedure modifies destination */
csp_iface_t * iface = NULL; /* Interface iterator */
csp_iface_t * next_iface = NULL; /* Reference to keep track of packet copying */

/* Try to find the destination on any local subnets */
int local_found = 0;
while ((iface = csp_iflist_get_by_subnet(idout->dst, iface)) != NULL) {

local_found = 1;

/* Do not send back to same inteface (split horizon)
* This check is is similar to that below, but faster */
if (iface == routed_from) {
/* Do not send back to same inteface (split horizon) */
if (is_same_subnet(iface, routed_from)) {
continue;
}

/* Do not send to interface with similar subnet (split horizon) */
if (csp_iflist_is_within_subnet(iface->addr, routed_from)) {
continue;
}
if (next_iface != NULL) {
csp_packet_t * copy = csp_buffer_clone(packet);

/* Apply outgoing interface address to packet */
if ((from_me) && (idout->src == 0)) {
_idout.src = iface->addr;
convert_broadcast(idout, &idout_copy, next_iface);
send_packet(&idout_copy, copy, next_iface, via, from_me);
}

/* Rewrite routed brodcast (L3) to local (L2) when arriving at the interface */
if (csp_id_is_broadcast(idout->dst, iface)) {
_idout.dst = csp_id_get_max_nodeid();
}

/* Todo: Find an elegant way to avoid making a copy when only a single destination interface
* is found. But without looping the list twice. And without using stack memory.
* Is this even possible? */
copy = csp_buffer_clone(packet);
if (copy != NULL) {
csp_send_direct_iface(&_idout, copy, iface, via, from_me);
}

next_iface = iface;
}

/* If the above worked, we don't want to look at the routing table */
if (local_found == 1) {
csp_buffer_free(packet);
if (local_found) {
if (next_iface != NULL) {
convert_broadcast(idout, &idout_copy, next_iface);
send_packet(&idout_copy, packet, next_iface, via, from_me);
} else {
csp_buffer_free(packet);
}
/* If a match was found, we don't want to look at the routing table */
return;
}

Expand All @@ -152,32 +173,27 @@ void csp_send_direct(csp_id_t* idout, csp_packet_t * packet, csp_iface_t * route
do {
route_found = 1;

/* Do not send back to same inteface (split horizon)
* This check is is similar to that below, but faster */
if (route->iface == routed_from) {
continue;
}

/* Do not send to interface with similar subnet (split horizon) */
if (csp_iflist_is_within_subnet(route->iface->addr, routed_from)) {
/* Do not send back to same inteface (split horizon) */
if (is_same_subnet(route->iface, routed_from)) {
continue;
}

/* Apply outgoing interface address to packet */
if ((from_me) && (idout->src == 0)) {
idout->src = route->iface->addr;
}

copy = csp_buffer_clone(packet);
if (copy != NULL) {
csp_send_direct_iface(idout, copy, route->iface, route->via, from_me);
if (next_iface != NULL) {
csp_packet_t * copy = csp_buffer_clone(packet);
send_packet(&idout_copy, copy, next_iface, via, from_me);
}
next_iface = route->iface;
via = route->via;
} while ((route = csp_rtable_search_backward(route)) != NULL);
}

/* If the above worked, we don't want to look at default interfaces */
if (route_found == 1) {
csp_buffer_free(packet);
if (next_iface != NULL) {
send_packet(&idout_copy, packet, next_iface, via, from_me);
} else {
csp_buffer_free(packet);
}
return;
}

Expand All @@ -186,30 +202,20 @@ void csp_send_direct(csp_id_t* idout, csp_packet_t * packet, csp_iface_t * route
/* Try to send via default interfaces */
while ((iface = csp_iflist_get_by_isdfl(iface)) != NULL) {

/* Do not send back to same inteface (split horizon)
* This check is is similar to that below, but faster */
if (iface == routed_from) {
if (is_same_subnet(iface, routed_from)) {
continue;
}

/* Do not send to interface with similar subnet (split horizon) */
if (csp_iflist_is_within_subnet(iface->addr, routed_from)) {
continue;
}

/* Apply outgoing interface address to packet */
if ((from_me) && (idout->src == 0)) {
idout->src = iface->addr;
}

/* Todo: Find an elegant way to avoid making a copy when only a single destination interface
* is found. But without looping the list twice. And without using stack memory.
* Is this even possible? */
copy = csp_buffer_clone(packet);
if (copy != NULL) {
csp_send_direct_iface(idout, copy, iface, via, from_me);
if (next_iface != NULL) {
csp_packet_t * copy = csp_buffer_clone(packet);
send_packet(&idout_copy, copy, next_iface, via, from_me);
}
next_iface = iface;
}

if (next_iface != NULL) {
send_packet(&idout_copy, packet, next_iface, via, from_me);
return;
}

csp_buffer_free(packet);
Expand Down
Loading