/**
* Try with next host in the (already shuffled) list.
*/
static void
uhc_try_next(void)
{
host_addr_t addr;
g_assert(uhc_connecting);
g_assert(uhc_ctx.timeout_ev == NULL);
if (!uhc_pick()) {
uhc_connecting = FALSE;
return;
}
/*
* The following may recurse if resolution is synchronous, but
* we're protected by the `attempts' counter.
*/
if (string_to_host_addr(uhc_ctx.host, NULL, &addr)) {
uhc_ctx.addr = addr;
if (GNET_PROPERTY(bootstrap_debug))
g_debug("BOOT UDP host cache \"%s\"", uhc_ctx.host);
uhc_send_ping();
} else {
(void) adns_resolve(uhc_ctx.host, settings_dns_net(),
uhc_host_resolved, NULL);
}
}
/**
* Request asynchronous DNS resolution for item, prior to inserting to
* the whitelist or updating the existing host address (when revalidating).
*/
static void
whitelist_dns_resolve(struct whitelist *item, bool revalidate)
{
struct whitelist_dns *ctx;
char *host;
g_assert(item != NULL);
g_assert(revalidate || !is_host_addr(item->addr));
g_assert(item->host != NULL);
/*
* Since resolution is normally going to happen asynchronously, we must
* keep track of the generation at which the resolution was requested.
*/
WALLOC(ctx);
ctx->item = item;
ctx->generation = whitelist_generation;
ctx->revalidate = revalidate;
host = item->host->name;
if (adns_resolve(host, settings_dns_net(), whitelist_dns_cb, ctx)) {
/* Asynchronous resolution */
if (GNET_PROPERTY(whitelist_debug) > 1)
log_whitelist_item(item, "asynchronously resolving");
} else {
/* Synchronous resolution, whitelist_dns_cb() already called */
}
}
/**
* Loads the whitelist into memory.
*/
static void G_COLD
whitelist_retrieve(void)
{
char line[1024];
FILE *f;
filestat_t st;
unsigned linenum = 0;
file_path_t fp[1];
whitelist_generation++;
file_path_set(fp, settings_config_dir(), whitelist_file);
f = file_config_open_read_norename("Host Whitelist", fp, N_ITEMS(fp));
if (!f)
return;
if (fstat(fileno(f), &st)) {
g_warning("%s(): fstat() failed: %m", G_STRFUNC);
fclose(f);
return;
}
while (fgets(line, sizeof line, f)) {
pslist_t *sl_addr, *sl;
const char *endptr, *start;
host_addr_t addr;
uint16 port;
uint8 bits;
bool item_ok;
bool use_tls;
char *hname;
linenum++;
if (!file_line_chomp_tail(line, sizeof line, NULL)) {
g_warning("%s(): line %u too long, aborting", G_STRFUNC, linenum);
break;
}
if (file_line_is_skipable(line))
continue;
sl_addr = NULL;
addr = zero_host_addr;
endptr = NULL;
hname = NULL;
endptr = is_strprefix(line, "tls:");
if (endptr) {
use_tls = TRUE;
start = endptr;
} else {
use_tls = FALSE;
start = line;
}
port = 0;
if (string_to_host_addr_port(start, &endptr, &addr, &port)) {
sl_addr = name_to_host_addr(host_addr_to_string(addr),
settings_dns_net());
} else if (string_to_host_or_addr(start, &endptr, &addr)) {
uchar c = *endptr;
switch (c) {
case '\0':
case ':':
case '/':
break;
default:
if (!is_ascii_space(c))
endptr = NULL;
}
if (!endptr) {
g_warning("%s(): line %d: "
"expected a hostname or IP address \"%s\"",
G_STRFUNC, linenum, line);
continue;
}
/* Terminate the string for name_to_host_addr() */
hname = h_strndup(start, endptr - start);
} else {
g_warning("%s(): line %d: expected hostname or IP address \"%s\"",
G_STRFUNC, linenum, line);
continue;
}
g_assert(sl_addr != NULL || hname != NULL);
g_assert(NULL != endptr);
bits = 0;
item_ok = TRUE;
/*
* When an explicit address is given (no hostname) and with no
* port, one can suffix the address with bits to indicate a CIDR
* range of whitelisted addresses.
*/
if (0 == port) {
/* Ignore trailing items separated by a space */
while ('\0' != *endptr && !is_ascii_space(*endptr)) {
uchar c = *endptr++;
if (':' == c) {
int error;
uint32 v;
if (0 != port) {
g_warning("%s(): line %d: multiple colons after host",
G_STRFUNC, linenum);
item_ok = FALSE;
break;
}
v = parse_uint32(endptr, &endptr, 10, &error);
port = (error || v > 0xffff) ? 0 : v;
if (0 == port) {
g_warning("%s(): line %d: "
"invalid port value after host",
G_STRFUNC, linenum);
item_ok = FALSE;
break;
}
} else if ('/' == c) {
const char *ep;
uint32 mask;
if (0 != bits) {
g_warning("%s(): line %d: "
"multiple slashes after host", G_STRFUNC, linenum);
item_ok = FALSE;
break;
}
if (string_to_ip_strict(endptr, &mask, &ep)) {
if (!host_addr_is_ipv4(addr)) {
g_warning("%s(): line %d: "
"IPv4 netmask after non-IPv4 address",
G_STRFUNC, linenum);
item_ok = FALSE;
break;
}
endptr = ep;
if (0 == (bits = netmask_to_cidr(mask))) {
g_warning("%s(): line %d: "
"IPv4 netmask after non-IPv4 address",
G_STRFUNC, linenum);
item_ok = FALSE;
break;
}
} else {
int error;
uint32 v;
v = parse_uint32(endptr, &endptr, 10, &error);
if (
error ||
0 == v ||
(v > 32 && host_addr_is_ipv4(addr)) ||
(v > 128 && host_addr_is_ipv6(addr))
) {
g_warning("%s(): line %d: "
"invalid numeric netmask after host",
G_STRFUNC, linenum);
item_ok = FALSE;
break;
}
bits = v;
}
} else {
g_warning("%s(): line %d: "
"unexpected character after host", G_STRFUNC, linenum);
item_ok = FALSE;
break;
}
}
}
if (item_ok) {
struct whitelist *item;
if (hname) {
item = whitelist_hostname_create(use_tls, hname, port);
whitelist_dns_resolve(item, FALSE);
} else {
PSLIST_FOREACH(sl_addr, sl) {
host_addr_t *aptr = sl->data;
g_assert(aptr != NULL);
item = whitelist_addr_create(use_tls, *aptr, port, bits);
whitelist_add(item);
}
}
} else {
/* adns interface functions (UI -> Core)*/
gboolean
guc_adns_resolve(const char *hostname,
adns_callback_t user_callback, gpointer user_data)
{
return adns_resolve(hostname, settings_dns_net(), user_callback, user_data);
}