void strategy_update_remote_addr_list(vpn_ctx_t *ctx) {
int i;
time_t now;
struct sockaddr *remote_addrp = ctx->remote_addrp;
time(&now);
socklen_t remote_addrlen = ctx->remote_addrlen;
// if already in list, update time and return
for (i = 0; i < ctx->nknown_addr; i++) {
if (remote_addrlen == ctx->known_addrs[i].addrlen) {
if (0 == memcmp(remote_addrp, &ctx->known_addrs[i].addr,
remote_addrlen)) {
ctx->known_addrs[i].last_recv_time = now;
return;
}
}
}
// if address list is not full, just append remote addr
if (ctx->nknown_addr < ctx->args->concurrency) {
save_addr(&ctx->known_addrs[ctx->nknown_addr], remote_addrp,
remote_addrlen, now);
ctx->nknown_addr++;
return;
}
// if full, replace the oldest
addr_info_t *oldest_addr_info = NULL;
for (i = 0; i < ctx->nknown_addr; i++) {
if (oldest_addr_info == NULL ||
oldest_addr_info->last_recv_time >
ctx->known_addrs[i].last_recv_time) {
oldest_addr_info = &ctx->known_addrs[i];
}
}
if (oldest_addr_info) {
save_addr(oldest_addr_info, remote_addrp, remote_addrlen, now);
}
}
static ad_disc_cds_t *
srv_parse(uchar_t *msg, int len, int *scnt, int *maxcnt)
{
ad_disc_cds_t *cds;
ad_disc_cds_t *cds_res = NULL;
HEADER *hdr;
int i, qdcount, ancount, nscount, arcount;
uchar_t *ptr, *eom;
uchar_t *end;
uint16_t type;
/* LINTED E_FUNC_SET_NOT_USED */
uint16_t class __unused;
uint32_t rttl;
uint16_t size;
char namebuf[NS_MAXDNAME];
eom = msg + len;
hdr = (void *)msg;
ptr = msg + sizeof (HEADER);
qdcount = ntohs(hdr->qdcount);
ancount = ntohs(hdr->ancount);
nscount = ntohs(hdr->nscount);
arcount = ntohs(hdr->arcount);
/* skip the question section */
len = ns_skiprr(ptr, eom, ns_s_qd, qdcount);
if (len < 0) {
logger(LOG_ERR, "DNS query invalid message format");
return (NULL);
}
ptr += len;
/*
* Walk through the answer section, building the result array.
* The array size is +2 because we (possibly) add the preferred
* DC if it was not there, and an empty one (null termination).
*/
*maxcnt = ancount + 2;
cds_res = calloc(*maxcnt, sizeof (*cds_res));
if (cds_res == NULL) {
logger(LOG_ERR, "Out of memory");
return (NULL);
}
cds = cds_res;
for (i = 0; i < ancount; i++) {
len = dn_expand(msg, eom, ptr, namebuf,
sizeof (namebuf));
if (len < 0) {
logger(LOG_ERR, "DNS query invalid message format");
goto err;
}
ptr += len;
NS_GET16(type, ptr);
NS_GET16(class, ptr);
NS_GET32(rttl, ptr);
NS_GET16(size, ptr);
if ((end = ptr + size) > eom) {
logger(LOG_ERR, "DNS query invalid message format");
goto err;
}
if (type != T_SRV) {
ptr = end;
continue;
}
NS_GET16(cds->cds_ds.priority, ptr);
NS_GET16(cds->cds_ds.weight, ptr);
NS_GET16(cds->cds_ds.port, ptr);
len = dn_expand(msg, eom, ptr, cds->cds_ds.host,
sizeof (cds->cds_ds.host));
if (len < 0) {
logger(LOG_ERR, "DNS query invalid SRV record");
goto err;
}
cds->cds_ds.ttl = rttl;
if (DBG(DNS, 2)) {
logger(LOG_DEBUG, " %s", namebuf);
logger(LOG_DEBUG,
" ttl=%d pri=%d weight=%d %s:%d",
rttl, cds->cds_ds.priority, cds->cds_ds.weight,
cds->cds_ds.host, cds->cds_ds.port);
}
cds++;
/* move ptr to the end of current record */
ptr = end;
}
*scnt = (cds - cds_res);
/* skip the nameservers section (if any) */
len = ns_skiprr(ptr, eom, ns_s_ns, nscount);
if (len < 0) {
logger(LOG_ERR, "DNS query invalid message format");
goto err;
}
ptr += len;
/* walk through the additional records */
for (i = 0; i < arcount; i++) {
sa_family_t af;
len = dn_expand(msg, eom, ptr, namebuf,
sizeof (namebuf));
if (len < 0) {
logger(LOG_ERR, "DNS query invalid message format");
goto err;
}
ptr += len;
NS_GET16(type, ptr);
NS_GET16(class, ptr);
NS_GET32(rttl, ptr);
NS_GET16(size, ptr);
if ((end = ptr + size) > eom) {
logger(LOG_ERR, "DNS query invalid message format");
goto err;
}
switch (type) {
case ns_t_a:
af = AF_INET;
break;
case ns_t_aaaa:
af = AF_INET6;
break;
default:
continue;
}
if (DBG(DNS, 2)) {
char abuf[INET6_ADDRSTRLEN];
const char *ap;
ap = inet_ntop(af, ptr, abuf, sizeof (abuf));
logger(LOG_DEBUG, " %s %s %s",
(af == AF_INET) ? "A " : "AAAA",
(ap) ? ap : "?", namebuf);
}
/* Find the server, add to its address list. */
for (cds = cds_res; cds->cds_ds.host[0] != '\0'; cds++)
if (0 == strcmp(namebuf, cds->cds_ds.host))
save_addr(cds, af, ptr, size);
/* move ptr to the end of current record */
ptr = end;
}
return (cds_res);
err:
free(cds_res);
return (NULL);
}
