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authorDaniel Stenberg <daniel@haxx.se>2019-02-10 00:10:18 +0100
committerDaniel Stenberg <daniel@haxx.se>2019-02-11 08:57:54 +0100
commit81a9fe4e92e263621c2117fdeb1603fe576006ad (patch)
treed01b4a5e9decd6e0d625a823ff050f5f23d5376a /lib/hostip.c
parente81cd9028f2ef6656df6653dcf7871a5fa081e2e (diff)
downloadcurl-81a9fe4e92e263621c2117fdeb1603fe576006ad.tar.gz
hostip: make create_hostcache_id avoid alloc + free
Closes #3544
Diffstat (limited to 'lib/hostip.c')
-rw-r--r--lib/hostip.c93
1 files changed, 24 insertions, 69 deletions
diff --git a/lib/hostip.c b/lib/hostip.c
index 8a62a34ec..0c6615986 100644
--- a/lib/hostip.c
+++ b/lib/hostip.c
@@ -73,6 +73,8 @@
#define USE_ALARM_TIMEOUT
#endif
+#define MAX_HOSTCACHE_LEN (255 + 7) /* max FQDN + colon + port number + zero */
+
/*
* hostip.c explained
* ==================
@@ -198,23 +200,19 @@ Curl_printable_address(const Curl_addrinfo *ai, char *buf, size_t bufsize)
}
/*
- * Return a hostcache id string for the provided host + port, to be used by
- * the DNS caching.
+ * Create a hostcache id string for the provided host + port, to be used by
+ * the DNS caching. Without alloc.
*/
-static char *
-create_hostcache_id(const char *name, int port)
+static void
+create_hostcache_id(const char *name, int port, char *ptr, size_t buflen)
{
- /* create and return the new allocated entry */
- char *id = aprintf("%s:%d", name, port);
- char *ptr = id;
- if(ptr) {
- /* lower case the name part */
- while(*ptr && (*ptr != ':')) {
- *ptr = (char)TOLOWER(*ptr);
- ptr++;
- }
- }
- return id;
+ size_t len = strlen(name);
+ if(len > (buflen - 7))
+ len = buflen - 7;
+ /* store and lower case the name */
+ while(len--)
+ *ptr++ = (char)TOLOWER(*name++);
+ msnprintf(ptr, 7, ":%u", port);
}
struct hostcache_prune_data {
@@ -296,17 +294,13 @@ fetch_addr(struct connectdata *conn,
const char *hostname,
int port)
{
- char *entry_id = NULL;
struct Curl_dns_entry *dns = NULL;
size_t entry_len;
struct Curl_easy *data = conn->data;
+ char entry_id[MAX_HOSTCACHE_LEN];
/* 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 */
- if(!entry_id)
- return dns;
-
+ create_hostcache_id(hostname, port, entry_id, sizeof(entry_id));
entry_len = strlen(entry_id);
/* See if its already in our dns cache */
@@ -314,18 +308,7 @@ fetch_addr(struct connectdata *conn,
/* No entry found in cache, check if we might have a wildcard entry */
if(!dns && data->change.wildcard_resolve) {
- /*
- * Free the previous entry_id before requesting a new one to avoid leaking
- * memory
- */
- free(entry_id);
-
- entry_id = create_hostcache_id("*", port);
-
- /* If we can't create the entry id, fail */
- if(!entry_id)
- return dns;
-
+ create_hostcache_id("*", port, entry_id, sizeof(entry_id));
entry_len = strlen(entry_id);
/* See if it's already in our dns cache */
@@ -346,9 +329,6 @@ fetch_addr(struct connectdata *conn,
}
}
- /* free the allocated entry_id again */
- free(entry_id);
-
return dns;
}
@@ -471,7 +451,7 @@ Curl_cache_addr(struct Curl_easy *data,
const char *hostname,
int port)
{
- char *entry_id;
+ char entry_id[MAX_HOSTCACHE_LEN];
size_t entry_len;
struct Curl_dns_entry *dns;
struct Curl_dns_entry *dns2;
@@ -483,20 +463,16 @@ Curl_cache_addr(struct Curl_easy *data,
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 */
- if(!entry_id)
- return NULL;
- entry_len = strlen(entry_id);
-
/* Create a new cache entry */
dns = calloc(1, sizeof(struct Curl_dns_entry));
if(!dns) {
- free(entry_id);
return NULL;
}
+ /* Create an entry id, based upon the hostname and port */
+ create_hostcache_id(hostname, port, entry_id, sizeof(entry_id));
+ entry_len = strlen(entry_id);
+
dns->inuse = 1; /* the cache has the first reference */
dns->addr = addr; /* this is the address(es) */
time(&dns->timestamp);
@@ -508,16 +484,11 @@ Curl_cache_addr(struct Curl_easy *data,
(void *)dns);
if(!dns2) {
free(dns);
- free(entry_id);
return NULL;
}
dns = dns2;
dns->inuse++; /* mark entry as in-use */
-
- /* free the allocated entry_id */
- free(entry_id);
-
return dns;
}
@@ -900,10 +871,10 @@ CURLcode Curl_loadhostpairs(struct Curl_easy *data)
data->change.wildcard_resolve = false;
for(hostp = data->change.resolve; hostp; hostp = hostp->next) {
+ char entry_id[MAX_HOSTCACHE_LEN];
if(!hostp->data)
continue;
if(hostp->data[0] == '-') {
- char *entry_id;
size_t entry_len;
if(2 != sscanf(hostp->data + 1, "%255[^:]:%d", hostname, &port)) {
@@ -913,12 +884,7 @@ CURLcode Curl_loadhostpairs(struct Curl_easy *data)
}
/* 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 */
- if(!entry_id) {
- return CURLE_OUT_OF_MEMORY;
- }
-
+ create_hostcache_id(hostname, port, entry_id, sizeof(entry_id));
entry_len = strlen(entry_id);
if(data->share)
@@ -929,14 +895,10 @@ CURLcode Curl_loadhostpairs(struct Curl_easy *data)
if(data->share)
Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
-
- /* free the allocated entry_id again */
- free(entry_id);
}
else {
struct Curl_dns_entry *dns;
Curl_addrinfo *head = NULL, *tail = NULL;
- char *entry_id;
size_t entry_len;
char address[64];
#if !defined(CURL_DISABLE_VERBOSE_STRINGS)
@@ -1032,12 +994,7 @@ CURLcode Curl_loadhostpairs(struct Curl_easy *data)
}
/* 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 */
- if(!entry_id) {
- Curl_freeaddrinfo(head);
- return CURLE_OUT_OF_MEMORY;
- }
+ create_hostcache_id(hostname, port, entry_id, sizeof(entry_id));
entry_len = strlen(entry_id);
if(data->share)
@@ -1058,8 +1015,6 @@ CURLcode Curl_loadhostpairs(struct Curl_easy *data)
Curl_hash_delete(data->dns.hostcache, entry_id, entry_len + 1);
}
- /* free the allocated entry_id again */
- free(entry_id);
/* put this new host in the cache */
dns = Curl_cache_addr(data, head, hostname, port);