Re: [libvirt] [libvirt PATCHv3 09/10] add leasefile support
On 10/12/2011 03:50 PM, David L Stevens wrote:
This patch adds support for saving DHCP snooping leases to an on-disk
file and restoring saved leases that are still active on restart.
Signed-off-by: David L Stevensdlstev...@us.ibm.com
---
src/nwfilter/nwfilter_dhcpsnoop.c | 370 +++--
1 files changed, 353 insertions(+), 17 deletions(-)
diff --git a/src/nwfilter/nwfilter_dhcpsnoop.c
b/src/nwfilter/nwfilter_dhcpsnoop.c
index f784a29..eedf550 100644
--- a/src/nwfilter/nwfilter_dhcpsnoop.c
+++ b/src/nwfilter/nwfilter_dhcpsnoop.c
@@ -56,10 +56,21 @@
#include nwfilter_gentech_driver.h
#include nwfilter_ebiptables_driver.h
#include nwfilter_dhcpsnoop.h
+#include configmake.h
#define VIR_FROM_THIS VIR_FROM_NWFILTER
+#define LEASEFILE LOCALSTATEDIR /run/libvirt/network/nwfilter.leases
+#define TMPLEASEFILE LOCALSTATEDIR /run/libvirt/network/nwfilter.ltmp
+static int lease_fd = -1;
+static int nleases = 0; /* number of active leases */
+static int wleases = 0; /* number of written leases */
+
static virHashTablePtr SnoopReqs;
+static pthread_mutex_t SnoopLock;
+
+#define snoop_lock(){ pthread_mutex_lock(SnoopLock); }
+#define snoop_unlock() { pthread_mutex_unlock(SnoopLock); }
struct virNWFilterSnoopReq {
virConnectPtr conn;
@@ -90,7 +101,14 @@ struct iplease {
static struct iplease *ipl_getbyip(struct iplease *start, uint32_t ipaddr);
static void ipl_update(struct iplease *pl, uint32_t timeout);
-
+
+static struct iflease *getiflease(const char *ifname);
+static void lease_open(void);
+static void lease_close(void);
+static void lease_load(void);
+static void lease_save(struct iplease *ipl);
+static void lease_refresh(void);
+static void lease_restore(struct virNWFilterSnoopReq *req);
/*
* ipl_ladd - add an IP lease to a list
@@ -150,6 +168,7 @@ ipl_add(struct iplease *plnew)
ipl_update(pl, plnew-ipl_timeout);
return;
}
+nleases++;
if (VIR_ALLOC(pl) 0) {
virReportOOMError();
return;
@@ -184,6 +203,7 @@ ipl_add(struct iplease *plnew)
return;
}
ipl_tadd(pl);
+lease_save(pl);
}
/*
@@ -231,6 +251,7 @@ ipl_del(struct iplease *ipl)
req = ipl-ipl_req;
ipl_tdel(ipl);
+lease_save(ipl);
if (inet_ntop(AF_INET,ipl-ipl_ipaddr, ipbuf, sizeof(ipbuf))) {
ipstr = strdup(ipbuf);
@@ -248,6 +269,7 @@ ipl_del(struct iplease *ipl)
_(ipl_del inet_ntop failed (0x%08X)),
ipl-ipl_ipaddr);
VIR_FREE(ipl);
+nleases--;
}
/*
@@ -259,6 +281,7 @@ ipl_update(struct iplease *ipl, uint32_t timeout)
ipl_tdel(ipl);
ipl-ipl_timeout = timeout;
ipl_tadd(ipl);
+lease_save(ipl);
return;
}
@@ -275,8 +298,6 @@ ipl_getbyip(struct iplease *start, uint32_t ipaddr)
return pl;
}
-#define GRACE 5
-
/*
* ipl_trun - run the IP lease timeout list
*/
@@ -465,6 +486,19 @@ dhcpopen(const char *intf)
return handle;
}
+/*
+ * snoopReqFree - release a snoop Req
+ */
+static void
+snoopReqFree(struct virNWFilterSnoopReq *req)
+{
+if (req-ifname)
+VIR_FREE(req-ifname);
+if (req-vars)
+virNWFilterHashTableFree(req-vars);
+VIR_FREE(req);
+}
+
static void *
virNWFilterDHCPSnoop(void *req0)
{
@@ -479,12 +513,19 @@ virNWFilterDHCPSnoop(void *req0)
if (!handle)
return 0;
+/* restore any saved leases for this interface */
+snoop_lock();
+lease_restore(req);
+snoop_unlock();
+
ifindex = if_nametoindex(req-ifname);
while (1) {
if (req-die)
break;
+snoop_lock();
ipl_trun(req);
+snoop_unlock();
packet = (struct eth *) pcap_next(handle,hdr);
@@ -494,16 +535,18 @@ virNWFilterDHCPSnoop(void *req0)
continue;
}
+snoop_lock();
dhcpdecode(req, packet, hdr.caplen);
+snoop_unlock();
}
+
+snoop_lock();
/* free all leases */
for (ipl = req-start; ipl; ipl = req-start)
ipl_del(ipl);
+snoop_unlock();
-/* free all req data */
-VIR_FREE(req-ifname);
-virNWFilterHashTableFree(req-vars);
-VIR_FREE(req);
+snoopReqFree(req);
return 0;
}
@@ -518,9 +561,12 @@ virNWFilterDHCPSnoopReq(virConnectPtr conn,
{
struct virNWFilterSnoopReq *req;
+snoop_lock();
req = virHashLookup(SnoopReqs, ifname);
-if (req)
+snoop_unlock();
+if (req) {
return 0;
+}
if (VIR_ALLOC(req) 0) {
virReportOOMError();
return 1;
@@ -533,28 +579,30 @@ virNWFilterDHCPSnoopReq(virConnectPtr conn,
req-ifname = strdup(ifname);
req-vars = virNWFilterHashTableCreate(0);
if (!req-vars) {
+snoopReqFree(req);
Following the lookup into the hashtable above you cannot just free the
request. I suppose you'd first have to remove it from the hash
[libvirt] [libvirt PATCHv3 09/10] add leasefile support
This patch adds support for saving DHCP snooping leases to an on-disk
file and restoring saved leases that are still active on restart.
Signed-off-by: David L Stevens dlstev...@us.ibm.com
---
src/nwfilter/nwfilter_dhcpsnoop.c | 370 +++--
1 files changed, 353 insertions(+), 17 deletions(-)
diff --git a/src/nwfilter/nwfilter_dhcpsnoop.c
b/src/nwfilter/nwfilter_dhcpsnoop.c
index f784a29..eedf550 100644
--- a/src/nwfilter/nwfilter_dhcpsnoop.c
+++ b/src/nwfilter/nwfilter_dhcpsnoop.c
@@ -56,10 +56,21 @@
#include nwfilter_gentech_driver.h
#include nwfilter_ebiptables_driver.h
#include nwfilter_dhcpsnoop.h
+#include configmake.h
#define VIR_FROM_THIS VIR_FROM_NWFILTER
+#define LEASEFILE LOCALSTATEDIR /run/libvirt/network/nwfilter.leases
+#define TMPLEASEFILE LOCALSTATEDIR /run/libvirt/network/nwfilter.ltmp
+static int lease_fd = -1;
+static int nleases = 0; /* number of active leases */
+static int wleases = 0; /* number of written leases */
+
static virHashTablePtr SnoopReqs;
+static pthread_mutex_t SnoopLock;
+
+#define snoop_lock(){ pthread_mutex_lock(SnoopLock); }
+#define snoop_unlock() { pthread_mutex_unlock(SnoopLock); }
struct virNWFilterSnoopReq {
virConnectPtr conn;
@@ -90,7 +101,14 @@ struct iplease {
static struct iplease *ipl_getbyip(struct iplease *start, uint32_t ipaddr);
static void ipl_update(struct iplease *pl, uint32_t timeout);
-
+
+static struct iflease *getiflease(const char *ifname);
+static void lease_open(void);
+static void lease_close(void);
+static void lease_load(void);
+static void lease_save(struct iplease *ipl);
+static void lease_refresh(void);
+static void lease_restore(struct virNWFilterSnoopReq *req);
/*
* ipl_ladd - add an IP lease to a list
@@ -150,6 +168,7 @@ ipl_add(struct iplease *plnew)
ipl_update(pl, plnew-ipl_timeout);
return;
}
+nleases++;
if (VIR_ALLOC(pl) 0) {
virReportOOMError();
return;
@@ -184,6 +203,7 @@ ipl_add(struct iplease *plnew)
return;
}
ipl_tadd(pl);
+lease_save(pl);
}
/*
@@ -231,6 +251,7 @@ ipl_del(struct iplease *ipl)
req = ipl-ipl_req;
ipl_tdel(ipl);
+lease_save(ipl);
if (inet_ntop(AF_INET, ipl-ipl_ipaddr, ipbuf, sizeof(ipbuf))) {
ipstr = strdup(ipbuf);
@@ -248,6 +269,7 @@ ipl_del(struct iplease *ipl)
_(ipl_del inet_ntop failed (0x%08X)),
ipl-ipl_ipaddr);
VIR_FREE(ipl);
+nleases--;
}
/*
@@ -259,6 +281,7 @@ ipl_update(struct iplease *ipl, uint32_t timeout)
ipl_tdel(ipl);
ipl-ipl_timeout = timeout;
ipl_tadd(ipl);
+lease_save(ipl);
return;
}
@@ -275,8 +298,6 @@ ipl_getbyip(struct iplease *start, uint32_t ipaddr)
return pl;
}
-#define GRACE 5
-
/*
* ipl_trun - run the IP lease timeout list
*/
@@ -465,6 +486,19 @@ dhcpopen(const char *intf)
return handle;
}
+/*
+ * snoopReqFree - release a snoop Req
+ */
+static void
+snoopReqFree(struct virNWFilterSnoopReq *req)
+{
+if (req-ifname)
+VIR_FREE(req-ifname);
+if (req-vars)
+virNWFilterHashTableFree(req-vars);
+VIR_FREE(req);
+}
+
static void *
virNWFilterDHCPSnoop(void *req0)
{
@@ -479,12 +513,19 @@ virNWFilterDHCPSnoop(void *req0)
if (!handle)
return 0;
+/* restore any saved leases for this interface */
+snoop_lock();
+lease_restore(req);
+snoop_unlock();
+
ifindex = if_nametoindex(req-ifname);
while (1) {
if (req-die)
break;
+snoop_lock();
ipl_trun(req);
+snoop_unlock();
packet = (struct eth *) pcap_next(handle, hdr);
@@ -494,16 +535,18 @@ virNWFilterDHCPSnoop(void *req0)
continue;
}
+snoop_lock();
dhcpdecode(req, packet, hdr.caplen);
+snoop_unlock();
}
+
+snoop_lock();
/* free all leases */
for (ipl = req-start; ipl; ipl = req-start)
ipl_del(ipl);
+snoop_unlock();
-/* free all req data */
-VIR_FREE(req-ifname);
-virNWFilterHashTableFree(req-vars);
-VIR_FREE(req);
+snoopReqFree(req);
return 0;
}
@@ -518,9 +561,12 @@ virNWFilterDHCPSnoopReq(virConnectPtr conn,
{
struct virNWFilterSnoopReq *req;
+snoop_lock();
req = virHashLookup(SnoopReqs, ifname);
-if (req)
+snoop_unlock();
+if (req) {
return 0;
+}
if (VIR_ALLOC(req) 0) {
virReportOOMError();
return 1;
@@ -533,28 +579,30 @@ virNWFilterDHCPSnoopReq(virConnectPtr conn,
req-ifname = strdup(ifname);
req-vars = virNWFilterHashTableCreate(0);
if (!req-vars) {
+snoopReqFree(req);
virReportOOMError();
return 1;
}
if (virNWFilterHashTablePutAll(vars, req-vars)) {
virNWFilterReportError(VIR_ERR_INTERNAL_ERROR,
- _(virNWFilterDHCPSnoopReq: can't copy
