void set_grid_direction_1(Graph *graph, Vertex *v, int *marks)
{
int i;
Vertex *next_v;
Arc *via;
// this procedure marks the link arc from v to its adjacencies.
// these marks serve to retain all non-visited arcs for further
// orientation step(s)
for (i = 0; i < v->nb_adjacencies; i++) {
// next adjacency
via = graph->arcs[v->adjacent_arcs[i]];
next_v = via->source == v->id
? graph->vertices[via->target]
: graph->vertices[via->source];
if (!marks[via->id]) {
marks[via->id] = 1;
// direction father->son
// the vertex `v` should be the source of via
if (via->source != v->id) {
reverse_direction(via);
}
set_grid_direction_1(graph, next_v, marks);
}
}
}
static string origin_direction(string direction)
{
switch (direction) {
case "up": return "below";
case "down": return "above";
default: return "the " + reverse_direction(direction);
}
}
void patch_multiarcs(Graph *graph, float percentage, int nb_lanes_max)
{
int i;
int random_id;
int new_arc_id;
Arc *random_arc;
int nb_arcs_to_add;
int arcs_cnt = 0;
int *lanes_cnt = (int *)malloc(sizeof(int) * graph->nb_arcs);
for (i = 0; i < graph->nb_arcs; i++) {
lanes_cnt[i] = 0;
}
// percentage cannot be greater than 1
if (percentage > 1) percentage = 1;
nb_arcs_to_add = (int)ceil(graph->nb_arcs * percentage);
// extend the memory allocation of arcs set
graph->arcs = (Arc **)realloc(graph->arcs, sizeof(Arc *) * (graph->nb_arcs + nb_arcs_to_add));
for (i = graph->nb_arcs; i < graph->nb_arcs + nb_arcs_to_add; i++) {
graph->arcs[i] = (Arc *)malloc(sizeof(Arc));
}
while (arcs_cnt < nb_arcs_to_add) {
random_id = rand_ij(&g_default_seed, 0, graph->nb_arcs);
if (lanes_cnt[random_id] >= nb_lanes_max -1) {
continue;
}
random_arc = graph->arcs[random_id];
new_arc_id = graph->nb_arcs + arcs_cnt;
// first duplicate the arc
// then decide whether to reverse the direction or not
set_arc_attr(graph, new_arc_id, random_arc->source, random_arc->target, random_arc->cost);
if (1 == rand_ij(&g_default_seed, 0, 2)) {
reverse_direction(graph->arcs[new_arc_id]);
}
lanes_cnt[random_id]++;
arcs_cnt++;
}
graph->nb_arcs += nb_arcs_to_add;
graph->per_multiarcs = (int) (percentage * 100);
free(lanes_cnt);
}
void set_grid_direction_2(Graph *graph, int *marks)
{
int i;
Arc *arc;
for (i = 0; i < graph->nb_arcs; i++) {
if (!marks[i]) {
arc = graph->arcs[i];
// set direction descendant->ancestor
reverse_direction(arc);
}
}
}
struct packet *new_icmp_packet(int address_family,
enum direction_t direction,
const char *type_string,
const char *code_string,
int protocol,
u32 tcp_start_sequence,
u32 payload_bytes,
s64 mtu,
char **error)
{
s32 type = -1; /* bad type; means "unknown so far" */
s32 code = -1; /* bad code; means "unknown so far" */
struct packet *packet = NULL; /* the newly-allocated result packet */
/* Calculate lengths in bytes of all sections of the packet.
* For now we only support the most common ICMP message
* format, which includes at the end the original outgoing IP
* header and the first 8 bytes after that (which will
* typically have the port info needed to demux the message).
*/
const int ip_fixed_bytes = ip_header_len(address_family);
const int ip_option_bytes = 0;
const int ip_header_bytes = ip_fixed_bytes + ip_option_bytes;
const int echoed_bytes = ip_fixed_bytes + ICMP_ECHO_BYTES;
const int icmp_bytes = icmp_header_len(address_family) + echoed_bytes;
const int ip_bytes = ip_header_bytes + icmp_bytes;
/* Sanity-check all the various lengths */
if (ip_option_bytes & 0x3) {
asprintf(error, "IP options are not padded correctly "
"to ensure IP header is a multiple of 4 bytes: "
"%d excess bytes", ip_option_bytes & 0x3);
goto error_out;
}
assert((ip_header_bytes & 0x3) == 0);
/* Parse the ICMP type and code */
if (parse_icmp_type_and_code(address_family, type_string, code_string,
&type, &code, error))
goto error_out;
assert(is_valid_u8(type));
assert(is_valid_u8(code));
/* Allocate and zero out a packet object of the desired size */
packet = packet_new(ip_bytes);
memset(packet->buffer, 0, ip_bytes);
packet->ip_bytes = ip_bytes;
packet->direction = direction;
packet->flags = 0;
packet->ecn = 0;
/* Set IP header fields */
const enum ip_ecn_t ecn = ECN_NONE;
set_packet_ip_header(packet, address_family, ip_bytes, direction, ecn,
icmp_protocol(address_family));
/* Find the start of the ICMP header and then populate common fields. */
void *icmp_header = packet_start(packet) + ip_header_bytes;
if (set_packet_icmp_header(packet, icmp_header, address_family,
type, code, mtu, error))
goto error_out;
/* All ICMP message types currently supported by this tool
* include a copy of the outbound IP header and the first few
* bytes inside. To ensure that the inbound ICMP message gets
* demuxed to the correct socket in the kernel, here we
* construct enough of a basic IP header and during test
* execution we fill in the port numbers and (if specified)
* TCP sequence number in the TCP header.
*/
u8 *echoed_ip = packet_echoed_ip_header(packet);
const int echoed_ip_bytes = (ip_fixed_bytes +
layer4_header_len(protocol) +
payload_bytes);
set_ip_header(echoed_ip, address_family, echoed_ip_bytes,
reverse_direction(direction), ecn, protocol);
if (protocol == IPPROTO_TCP) {
u32 *seq = packet_echoed_tcp_seq(packet);
*seq = htonl(tcp_start_sequence);
}
return packet;
error_out:
if (packet != NULL)
packet_free(packet);
return NULL;
}
