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-rw-r--r--Utilities/cmcurl/lib/hostip.c202
1 files changed, 174 insertions, 28 deletions
diff --git a/Utilities/cmcurl/lib/hostip.c b/Utilities/cmcurl/lib/hostip.c
index 886aeec..c2f9def 100644
--- a/Utilities/cmcurl/lib/hostip.c
+++ b/Utilities/cmcurl/lib/hostip.c
@@ -5,7 +5,7 @@
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
- * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
@@ -54,10 +54,12 @@
#include "sendf.h"
#include "hostip.h"
#include "hash.h"
+#include "rand.h"
#include "share.h"
#include "strerror.h"
#include "url.h"
#include "inet_ntop.h"
+#include "multiif.h"
#include "warnless.h"
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
@@ -366,6 +368,70 @@ Curl_fetch_addr(struct connectdata *conn,
}
/*
+ * Curl_shuffle_addr() shuffles the order of addresses in a 'Curl_addrinfo'
+ * struct by re-linking its linked list.
+ *
+ * The addr argument should be the address of a pointer to the head node of a
+ * `Curl_addrinfo` list and it will be modified to point to the new head after
+ * shuffling.
+ *
+ * Not declared static only to make it easy to use in a unit test!
+ *
+ * @unittest: 1608
+ */
+CURLcode Curl_shuffle_addr(struct Curl_easy *data, Curl_addrinfo **addr)
+{
+ CURLcode result = CURLE_OK;
+ const int num_addrs = Curl_num_addresses(*addr);
+
+ if(num_addrs > 1) {
+ Curl_addrinfo **nodes;
+ infof(data, "Shuffling %i addresses", num_addrs);
+
+ nodes = malloc(num_addrs*sizeof(*nodes));
+ if(nodes) {
+ int i;
+ unsigned int *rnd;
+ const size_t rnd_size = num_addrs * sizeof(*rnd);
+
+ /* build a plain array of Curl_addrinfo pointers */
+ nodes[0] = *addr;
+ for(i = 1; i < num_addrs; i++) {
+ nodes[i] = nodes[i-1]->ai_next;
+ }
+
+ rnd = malloc(rnd_size);
+ if(rnd) {
+ /* Fisher-Yates shuffle */
+ if(Curl_rand(data, (unsigned char *)rnd, rnd_size) == CURLE_OK) {
+ Curl_addrinfo *swap_tmp;
+ for(i = num_addrs - 1; i > 0; i--) {
+ swap_tmp = nodes[rnd[i] % (i + 1)];
+ nodes[rnd[i] % (i + 1)] = nodes[i];
+ nodes[i] = swap_tmp;
+ }
+
+ /* relink list in the new order */
+ for(i = 1; i < num_addrs; i++) {
+ nodes[i-1]->ai_next = nodes[i];
+ }
+
+ nodes[num_addrs-1]->ai_next = NULL;
+ *addr = nodes[0];
+ }
+ free(rnd);
+ }
+ else
+ result = CURLE_OUT_OF_MEMORY;
+ free(nodes);
+ }
+ else
+ result = CURLE_OUT_OF_MEMORY;
+ }
+ return result;
+}
+
+/*
* Curl_cache_addr() stores a 'Curl_addrinfo' struct in the DNS cache.
*
* When calling Curl_resolv() has resulted in a response with a returned
@@ -385,6 +451,13 @@ Curl_cache_addr(struct Curl_easy *data,
struct Curl_dns_entry *dns;
struct Curl_dns_entry *dns2;
+ /* shuffle addresses if requested */
+ if(data->set.dns_shuffle_addresses) {
+ CURLcode result = Curl_shuffle_addr(data, &addr);
+ if(!result)
+ return NULL;
+ }
+
/* Create an entry id, based upon the hostname and port */
entry_id = create_hostcache_id(hostname, port);
/* If we can't create the entry id, fail */
@@ -481,6 +554,17 @@ int Curl_resolv(struct connectdata *conn,
if(!Curl_ipvalid(conn))
return CURLRESOLV_ERROR;
+ /* notify the resolver start callback */
+ if(data->set.resolver_start) {
+ int st;
+ Curl_set_in_callback(data, true);
+ st = data->set.resolver_start(data->state.resolver, NULL,
+ data->set.resolver_start_client);
+ Curl_set_in_callback(data, false);
+ if(st)
+ return CURLRESOLV_ERROR;
+ }
+
/* If Curl_getaddrinfo() returns NULL, 'respwait' might be set to a
non-zero value indicating that we need to wait for the response to the
resolve call */
@@ -781,7 +865,7 @@ CURLcode Curl_loadhostpairs(struct Curl_easy *data)
{
struct curl_slist *hostp;
char hostname[256];
- int port;
+ int port = 0;
for(hostp = data->change.resolve; hostp; hostp = hostp->next) {
if(!hostp->data)
@@ -819,32 +903,95 @@ CURLcode Curl_loadhostpairs(struct Curl_easy *data)
}
else {
struct Curl_dns_entry *dns;
- Curl_addrinfo *addr;
+ Curl_addrinfo *head = NULL, *tail = NULL;
char *entry_id;
size_t entry_len;
- char buffer[256];
- char *address = &buffer[0];
+ char address[64];
+ char *addresses = NULL;
+ char *addr_begin;
+ char *addr_end;
+ char *port_ptr;
+ char *end_ptr;
+ char *host_end;
+ unsigned long tmp_port;
+ bool error = true;
+
+ host_end = strchr(hostp->data, ':');
+ if(!host_end ||
+ ((host_end - hostp->data) >= (ptrdiff_t)sizeof(hostname)))
+ goto err;
+
+ memcpy(hostname, hostp->data, host_end - hostp->data);
+ hostname[host_end - hostp->data] = '\0';
+
+ port_ptr = host_end + 1;
+ tmp_port = strtoul(port_ptr, &end_ptr, 10);
+ if(tmp_port > USHRT_MAX || end_ptr == port_ptr || *end_ptr != ':')
+ goto err;
+
+ port = (int)tmp_port;
+ addresses = end_ptr + 1;
+
+ while(*end_ptr) {
+ size_t alen;
+ Curl_addrinfo *ai;
+
+ addr_begin = end_ptr + 1;
+ addr_end = strchr(addr_begin, ',');
+ if(!addr_end)
+ addr_end = addr_begin + strlen(addr_begin);
+ end_ptr = addr_end;
+
+ /* allow IP(v6) address within [brackets] */
+ if(*addr_begin == '[') {
+ if(addr_end == addr_begin || *(addr_end - 1) != ']')
+ goto err;
+ ++addr_begin;
+ --addr_end;
+ }
- if(3 != sscanf(hostp->data, "%255[^:]:%d:%255s", hostname, &port,
- address)) {
- infof(data, "Couldn't parse CURLOPT_RESOLVE entry '%s'!\n",
- hostp->data);
- continue;
- }
+ alen = addr_end - addr_begin;
+ if(!alen)
+ continue;
+
+ if(alen >= sizeof(address))
+ goto err;
- /* allow IP(v6) address within [brackets] */
- if(address[0] == '[') {
- size_t alen = strlen(address);
- if(address[alen-1] != ']')
- /* it needs to also end with ] to be valid */
+ memcpy(address, addr_begin, alen);
+ address[alen] = '\0';
+
+#ifndef ENABLE_IPV6
+ if(strchr(address, ':')) {
+ infof(data, "Ignoring resolve address '%s', missing IPv6 support.\n",
+ address);
continue;
- address[alen-1] = 0; /* zero terminate there */
- address++; /* pass the open bracket */
+ }
+#endif
+
+ ai = Curl_str2addr(address, port);
+ if(!ai) {
+ infof(data, "Resolve address '%s' found illegal!\n", address);
+ goto err;
+ }
+
+ if(tail) {
+ tail->ai_next = ai;
+ tail = tail->ai_next;
+ }
+ else {
+ head = tail = ai;
+ }
}
- addr = Curl_str2addr(address, port);
- if(!addr) {
- infof(data, "Address in '%s' found illegal!\n", hostp->data);
+ if(!head)
+ goto err;
+
+ error = false;
+ err:
+ if(error) {
+ infof(data, "Couldn't parse CURLOPT_RESOLVE entry '%s'!\n",
+ hostp->data);
+ Curl_freeaddrinfo(head);
continue;
}
@@ -852,10 +999,9 @@ CURLcode Curl_loadhostpairs(struct Curl_easy *data)
entry_id = create_hostcache_id(hostname, port);
/* If we can't create the entry id, fail */
if(!entry_id) {
- Curl_freeaddrinfo(addr);
+ Curl_freeaddrinfo(head);
return CURLE_OUT_OF_MEMORY;
}
-
entry_len = strlen(entry_id);
if(data->share)
@@ -869,7 +1015,7 @@ CURLcode Curl_loadhostpairs(struct Curl_easy *data)
if(!dns) {
/* if not in the cache already, put this host in the cache */
- dns = Curl_cache_addr(data, addr, hostname, port);
+ dns = Curl_cache_addr(data, head, hostname, port);
if(dns) {
dns->timestamp = 0; /* mark as added by CURLOPT_RESOLVE */
/* release the returned reference; the cache itself will keep the
@@ -880,19 +1026,19 @@ CURLcode Curl_loadhostpairs(struct Curl_easy *data)
else {
/* this is a duplicate, free it again */
infof(data, "RESOLVE %s:%d is already cached, %s not stored!\n",
- hostname, port, address);
- Curl_freeaddrinfo(addr);
+ hostname, port, addresses);
+ Curl_freeaddrinfo(head);
}
if(data->share)
Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
if(!dns) {
- Curl_freeaddrinfo(addr);
+ Curl_freeaddrinfo(head);
return CURLE_OUT_OF_MEMORY;
}
infof(data, "Added %s:%d:%s to DNS cache\n",
- hostname, port, address);
+ hostname, port, addresses);
}
}
data->change.resolve = NULL; /* dealt with now */
generated by cgit v0.12 at 2024-09-18 15:12:04 (GMT)