Move platform-dependent pcap_t data out of the pcap_t structure.

Put the private data right after the pcap_t structure, with a pointer to
it in the pcap_t.

The initial goal is to allow new pcap modules to be added without having
to hack pcap-int.h.

In the longer term, we may want to freeze the pcap_t structure, except
possibly for adding new method pointers at the end, and provide an ABI
for adding modules.

We also put the stuff used by the read path at the beginning of the
pcap_t structure, to try to keep it on the same set of cache lines.

1 files changed, 14 insertions, 5 deletions

diff --git a/pcap-bt-linux.c b/pcap-bt-linux.c
index 037f64b9..e2268b8e 100644
--- a/pcap-bt-linux.c
+++ b/pcap-bt-linux.c
@@ -70,6 +70,13 @@ static int bt_inject_linux(pcap_t *, const void *, size_t);
 static int bt_setdirection_linux(pcap_t *, pcap_direction_t);
 static int bt_stats_linux(pcap_t *, struct pcap_stat *);
 
+/*
+ * Private data for capturing on Linux Bluetooth devices.
+ */
+struct pcap_bt {
+	int dev_id;		/* device ID of device we're bound to */
+};
+
 int 
 bt_findalldevs(pcap_if_t **alldevsp, char *err_str)
 {
@@ -169,7 +176,7 @@ bt_create(const char *device, char *ebuf, int *is_ours)
 	/* OK, it's probably ours. */
 	*is_ours = 1;
 
-	p = pcap_create_common(device, ebuf);
+	p = pcap_create_common(device, ebuf, sizeof (struct pcap_bt));
 	if (p == NULL)
 		return (NULL);
 
@@ -180,6 +187,7 @@ bt_create(const char *device, char *ebuf, int *is_ours)
 static int
 bt_activate(pcap_t* handle)
 {
+	struct pcap_bt *handlep = handle->private;
 	struct sockaddr_hci addr;
 	int opt;
 	int		dev_id;
@@ -208,7 +216,7 @@ bt_activate(pcap_t* handle)
 	handle->getnonblock_op = pcap_getnonblock_fd;
 	handle->setnonblock_op = pcap_setnonblock_fd;
 	handle->stats_op = bt_stats_linux;
-	handle->md.ifindex = dev_id;
+	handlep->dev_id = dev_id;
 	
 	/* Create HCI socket */
 	handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
@@ -253,13 +261,13 @@ bt_activate(pcap_t* handle)
 
 	/* Bind socket to the HCI device */
 	addr.hci_family = AF_BLUETOOTH;
-	addr.hci_dev = handle->md.ifindex;
+	addr.hci_dev = handlep->dev_id;
 #ifdef SOCKADDR_HCI_HAS_HCI_CHANNEL
 	addr.hci_channel = HCI_CHANNEL_RAW;
 #endif
 	if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
 		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
-		    "Can't attach to device %d: %s", handle->md.ifindex,
+		    "Can't attach to device %d: %s", handlep->dev_id,
 		    strerror(errno));
 		goto close_fail;
 	}
@@ -374,10 +382,11 @@ bt_inject_linux(pcap_t *handle, const void *buf, size_t size)
 static int 
 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 {
+	struct pcap_bt *handlep = handle->private;
 	int ret;
 	struct hci_dev_info dev_info;
 	struct hci_dev_stats * s = &dev_info.stat;
-	dev_info.dev_id = handle->md.ifindex;
+	dev_info.dev_id = handlep->dev_id;
 	
 	/* ignore eintr */
 	do {