* use FIONREAD to minimize allocated buffer size when reading incoming packets

* enforce a cache size limit


git-svn-id: file:///home/lennart/svn/public/avahi/trunk@96 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe

7 files changed, 44 insertions, 12 deletions

diff --git a/avahi-core/cache.c b/avahi-core/cache.c
index 433f5a8..8f9ffaf 100644
--- a/avahi-core/cache.c
+++ b/avahi-core/cache.c
@@ -28,6 +28,8 @@
 #include "util.h"
 #include "cache.h"
 
+#define AVAHI_MAX_CACHE_ENTRIES 200
+
 static void remove_entry(AvahiCache *c, AvahiCacheEntry *e) {
     AvahiCacheEntry *t;
 
@@ -55,6 +57,8 @@ static void remove_entry(AvahiCache *c, AvahiCacheEntry *e) {
     avahi_record_unref(e->record);
     
     g_free(e);
+
+    g_assert(c->n_entries-- >= 1);
 }
 
 AvahiCache *avahi_cache_new(AvahiServer *server, AvahiInterface *iface) {
@@ -67,6 +71,7 @@ AvahiCache *avahi_cache_new(AvahiServer *server, AvahiInterface *iface) {
     c->hash_table = g_hash_table_new((GHashFunc) avahi_key_hash, (GEqualFunc) avahi_key_equal);
 
     AVAHI_LLIST_HEAD_INIT(AvahiCacheEntry, c->entries);
+    c->n_entries = 0;
     
     return c;
 }
@@ -76,6 +81,7 @@ void avahi_cache_free(AvahiCache *c) {
 
     while (c->entries)
         remove_entry(c, c->entries);
+    g_assert(c->n_entries == 0);
     
     g_hash_table_destroy(c->hash_table);
     
@@ -293,6 +299,11 @@ void avahi_cache_update(AvahiCache *c, AvahiRecord *r, gboolean cache_flush, con
             /* No entry found, therefore we create a new one */
             
 /*             g_message("couldn't find matching cache entry");  */
+
+            if (c->n_entries >= AVAHI_MAX_CACHE_ENTRIES)
+                return;
+
+            c->n_entries++;
             
             e = g_new(AvahiCacheEntry, 1);
             e->cache = c;
diff --git a/avahi-core/cache.h b/avahi-core/cache.h
index 7496568..e4bdbc4 100644
--- a/avahi-core/cache.h
+++ b/avahi-core/cache.h
@@ -65,6 +65,8 @@ struct AvahiCache {
     GHashTable *hash_table;
 
     AVAHI_LLIST_HEAD(AvahiCacheEntry, entries);
+
+    guint n_entries;
 };
 
 AvahiCache *avahi_cache_new(AvahiServer *server, AvahiInterface *interface);
diff --git a/avahi-core/dns.c b/avahi-core/dns.c
index 4294c1e..9e19c9e 100644
--- a/avahi-core/dns.c
+++ b/avahi-core/dns.c
@@ -38,8 +38,8 @@ AvahiDnsPacket* avahi_dns_packet_new(guint mtu) {
 
     if (mtu <= 0)
         max_size = AVAHI_DNS_PACKET_MAX_SIZE;
-    else if (mtu >= 48)
-        max_size = mtu - 48;
+    else if (mtu >= AVAHI_DNS_PACKET_EXTRA_SIZE)
+        max_size = mtu - AVAHI_DNS_PACKET_EXTRA_SIZE;
     else
         max_size = 0;
 
diff --git a/avahi-core/dns.h b/avahi-core/dns.h
index a6d7895..03d9798 100644
--- a/avahi-core/dns.h
+++ b/avahi-core/dns.h
@@ -28,6 +28,7 @@
 
 #define AVAHI_DNS_PACKET_MAX_SIZE 9000
 #define AVAHI_DNS_PACKET_HEADER_SIZE 12
+#define AVAHI_DNS_PACKET_EXTRA_SIZE 48
 
 typedef struct AvahiDnsPacket {
     guint size, rindex, max_size;
diff --git a/avahi-core/netlink.c b/avahi-core/netlink.c
index e3cc3fa..88979e1 100644
--- a/avahi-core/netlink.c
+++ b/avahi-core/netlink.c
@@ -26,6 +26,7 @@
 #include <unistd.h>
 #include <errno.h>
 #include <string.h>
+#include <sys/ioctl.h>
 
 #include "netlink.h"
 
@@ -43,16 +44,18 @@ gboolean avahi_netlink_work(AvahiNetlink *nl, gboolean block) {
     g_assert(nl);
 
     for (;;) {
-        guint8 replybuf[64*1024];
         ssize_t bytes;
-        struct nlmsghdr *p = (struct nlmsghdr *) replybuf;
+        struct nlmsghdr *p;
+        guint8 buffer[64*1024];
 
-        if ((bytes = recv(nl->fd, replybuf, sizeof(replybuf), block ? 0 : MSG_DONTWAIT)) < 0) {
+        p = (struct nlmsghdr *) buffer;
+
+        if ((bytes = recv(nl->fd, buffer, sizeof(buffer), block ? 0 : MSG_DONTWAIT)) < 0) {
 
             if (errno == EAGAIN || errno == EINTR)
                 break;
 
-            g_warning("NETLINK: recv() failed");
+            g_warning("NETLINK: recv() failed: %s", strerror(errno));
             return FALSE;
         }
 
@@ -160,7 +163,7 @@ AvahiNetlink *avahi_netlink_new(GMainContext *context, gint priority, guint32 gr
 
 void avahi_netlink_free(AvahiNetlink *nl) {
     g_assert(nl);
-    
+
     g_source_destroy(nl->source);
     g_source_unref(nl->source);
     g_main_context_unref(nl->context);
diff --git a/avahi-core/server.c b/avahi-core/server.c
index 9356fec..da946e5 100644
--- a/avahi-core/server.c
+++ b/avahi-core/server.c
@@ -36,7 +36,7 @@
 #include "socket.h"
 #include "browse.h"
 
-#define AVAHI_HOST_RR_HOLDOFF_MSEC 1000
+#define AVAHI_HOST_RR_HOLDOFF_MSEC 2000
 
 static void free_entry(AvahiServer*s, AvahiEntry *e) {
     AvahiEntry *t;
diff --git a/avahi-core/socket.c b/avahi-core/socket.c
index a2264ce..7007452 100644
--- a/avahi-core/socket.c
+++ b/avahi-core/socket.c
@@ -424,13 +424,19 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv4(gint fd, struct sockaddr_in *ret_sa,
     ssize_t l;
     struct cmsghdr *cmsg;
     gboolean found_ttl = FALSE, found_iface = FALSE;
+    guint ms;
 
     g_assert(fd >= 0);
     g_assert(ret_sa);
     g_assert(ret_iface);
     g_assert(ret_ttl);
 
-    p = avahi_dns_packet_new(0);
+    if (ioctl(fd, FIONREAD, &ms) < 0) {
+        g_warning("ioctl(): %s", strerror(errno));
+        goto fail;
+    }
+
+    p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
 
     io.iov_base = AVAHI_DNS_PACKET_DATA(p);
     io.iov_len = p->max_size;
@@ -445,7 +451,7 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv4(gint fd, struct sockaddr_in *ret_sa,
     msg.msg_flags = 0;
     
     if ((l = recvmsg(fd, &msg, 0)) < 0) {
-        g_warning("recvmsg(): %s\n", strerror(errno));
+        g_warning("recvmsg(): %s", strerror(errno));
         goto fail;
     }
 
@@ -502,6 +508,8 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv6(gint fd, struct sockaddr_in6 *ret_sa,
     struct iovec io;
     uint8_t aux[64];
     ssize_t l;
+    guint ms;
+    
     struct cmsghdr *cmsg;
     gboolean found_ttl = FALSE, found_iface = FALSE;
 
@@ -510,7 +518,12 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv6(gint fd, struct sockaddr_in6 *ret_sa,
     g_assert(ret_iface);
     g_assert(ret_ttl);
 
-    p = avahi_dns_packet_new(0);
+    if (ioctl(fd, FIONREAD, &ms) < 0) {
+        g_warning("ioctl(): %s", strerror(errno));
+        goto fail;
+    }
+    
+    p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
 
     io.iov_base = AVAHI_DNS_PACKET_DATA(p);
     io.iov_len = p->max_size;
@@ -524,8 +537,10 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv6(gint fd, struct sockaddr_in6 *ret_sa,
     msg.msg_controllen = sizeof(aux);
     msg.msg_flags = 0;
     
-    if ((l = recvmsg(fd, &msg, 0)) < 0)
+    if ((l = recvmsg(fd, &msg, 0)) < 0) {
+        g_warning("recvmsg(): %s", strerror(errno));
         goto fail;
+    }
 
     p->size = (size_t) l;