trafgen: Delegate creation of rfraw to dev_io API

Simplify a bit of creation rfraw device by delegating it to the dev_io
API, also in case the output device is pcap file the --rfraw option
sets the link type to ieee80211 radio tap.

Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

4 files changed, 48 insertions, 19 deletions

diff --git a/trafgen.8 b/trafgen.8
index 50deacf..67aaaf9 100644
--- a/trafgen.8
+++ b/trafgen.8
@@ -98,7 +98,8 @@ a bigger memory footprint for the ring buffer.
 In case the output networking device is a wireless device, it is possible with
 trafgen to turn this into monitor mode and create a mon<X> device that trafgen
 will be transmitting on instead of wlan<X>, for instance. This enables trafgen
-to inject raw 802.11 frames.
+to inject raw 802.11 frames. In case if the output is a pcap file the link type
+is set to 127 (ieee80211 radio tap).
 .PP
 .SS -s <ipv4>, --smoke-test <ipv4>
 In case this option is enabled, trafgen will perform a smoke test. In other
diff --git a/trafgen.c b/trafgen.c
index 5f3555a..207b680 100644
--- a/trafgen.c
+++ b/trafgen.c
@@ -45,7 +45,6 @@
 #include "lockme.h"
 #include "privs.h"
 #include "proc.h"
-#include "mac80211.h"
 #include "ioops.h"
 #include "irq.h"
 #include "config.h"
@@ -85,7 +84,7 @@ struct ctx {
 	unsigned long num;
 	unsigned int cpus;
 	uid_t uid; gid_t gid;
-	char *device, *device_trans, *rhost;
+	char *device, *rhost;
 	struct sockaddr_in dest;
 	struct shaper sh;
 	char *packet_str;
@@ -1023,7 +1022,7 @@ static unsigned int generate_srand_seed(void)
 
 static void on_panic_del_rfmon(void *arg)
 {
-	leave_rfmon_mac80211(arg);
+	dev_io_close(arg);
 }
 
 int main(int argc, char **argv)
@@ -1283,15 +1282,6 @@ int main(int argc, char **argv)
 		set_system_socket_memory(vals, array_size(vals));
 	xlockme();
 
-	if (ctx.rfraw) {
-		ctx.device_trans = xstrdup(ctx.device);
-		xfree(ctx.device);
-
-		enter_rfmon_mac80211(ctx.device_trans, &ctx.device);
-		panic_handler_add(on_panic_del_rfmon, ctx.device);
-		sleep(0);
-	}
-
 	if (ctx.pcap_in) {
 		ctx.dev_in = dev_io_open(ctx.pcap_in, DEV_IO_IN);
 		if (!ctx.dev_in)
@@ -1302,6 +1292,13 @@ int main(int argc, char **argv)
 	if (!ctx.dev_out)
 		panic("Failed to open output device\n");
 
+	if (ctx.rfraw) {
+		if (dev_io_link_type_set(ctx.dev_out, LINKTYPE_IEEE802_11_RADIOTAP))
+			panic("Failed to setup rfraw device\n");
+
+		panic_handler_add(on_panic_del_rfmon, ctx.dev_out);
+	}
+
 	protos_init(ctx.dev_out);
 
 	if (shaper_is_set(&ctx.sh) || (ctx.dev_in && dev_io_is_pcap(ctx.dev_in))
@@ -1357,9 +1354,6 @@ int main(int argc, char **argv)
 			die();
 	}
 
-	if (ctx.rfraw)
-		leave_rfmon_mac80211(ctx.device);
-
 	if (set_sock_mem)
 		reset_system_socket_memory(vals, array_size(vals));
 
@@ -1393,7 +1387,6 @@ thread_out:
 
 	argv_free(cpp_argv);
 	free(ctx.device);
-	free(ctx.device_trans);
 	free(ctx.rhost);
 	free(confname);
 	free(ctx.packet_str);
diff --git a/trafgen_dev.c b/trafgen_dev.c
index 80e7481..d7f1cd5 100644
--- a/trafgen_dev.c
+++ b/trafgen_dev.c
@@ -16,6 +16,8 @@
 #include "xmalloc.h"
 #include "pcap_io.h"
 #include "built_in.h"
+#include "mac80211.h"
+#include "linktype.h"
 #include "trafgen_dev.h"
 
 static int dev_pcap_open(struct dev_io *dev, const char *name, enum dev_io_mode_t mode)
@@ -164,9 +166,34 @@ static int dev_net_write(struct dev_io *dev, const uint8_t *buf, size_t len)
 	return sendto(dev->fd, buf, len, 0, (struct sockaddr *) &saddr, sizeof(saddr));
 }
 
+static int dev_net_set_link_type(struct dev_io *dev, int link_type)
+{
+	if (link_type != LINKTYPE_IEEE802_11 && link_type != LINKTYPE_IEEE802_11_RADIOTAP)
+		return 0;
+
+	dev->trans = xstrdup(dev->name);
+	xfree(dev->name);
+
+	enter_rfmon_mac80211(dev->trans, &dev->name);
+	dev->ifindex = __device_ifindex(dev->name);
+	dev->dev_type = device_type(dev->name);
+
+	return 0;
+}
+
+static void dev_net_close(struct dev_io *dev)
+{
+	if (dev->link_type == LINKTYPE_IEEE802_11 || dev->link_type == LINKTYPE_IEEE802_11_RADIOTAP)
+		leave_rfmon_mac80211(dev->name);
+
+	free(dev->trans);
+}
+
 static const struct dev_io_ops dev_net_ops = {
 	.open = dev_net_open,
 	.write = dev_net_write,
+	.set_link_type = dev_net_set_link_type,
+	.close = dev_net_close,
 };
 
 struct dev_io *dev_io_open(const char *name, enum dev_io_mode_t mode)
@@ -232,9 +259,15 @@ bool dev_io_is_pcap(struct dev_io *dev)
 	return dev->ops == &dev_pcap_ops;
 }
 
-void dev_io_link_type_set(struct dev_io *dev, int link_type)
+int dev_io_link_type_set(struct dev_io *dev, int link_type)
 {
+	if (dev->ops->set_link_type) {
+		if (dev->ops->set_link_type(dev, link_type))
+			return -1;
+	}
+
 	dev->link_type = link_type;
+	return 0;
 }
 
 int dev_io_ifindex_get(struct dev_io *dev)
diff --git a/trafgen_dev.h b/trafgen_dev.h
index 720c630..686a577 100644
--- a/trafgen_dev.h
+++ b/trafgen_dev.h
@@ -16,6 +16,7 @@ struct dev_io_ops;
 struct dev_io {
 	int fd;
 	char *name;
+	char *trans;
 	int ifindex;
 	int dev_type;
 	uint32_t link_type;
@@ -31,6 +32,7 @@ struct dev_io_ops {
 	int(*open) (struct dev_io *dev, const char *name, enum dev_io_mode_t mode);
 	int(*write) (struct dev_io *dev, const uint8_t *buf, size_t len);
 	int(*read) (struct dev_io *dev, uint8_t *buf, size_t len, struct timespec *tstamp);
+	int(*set_link_type) (struct dev_io *dev, int link_type);
 	void(*close) (struct dev_io *dev);
 };
 
@@ -41,7 +43,7 @@ extern int dev_io_read(struct dev_io *dev, uint8_t *buf, size_t len,
 extern int dev_io_ifindex_get(struct dev_io *dev);
 extern int dev_io_fd_get(struct dev_io *dev);
 extern const char *dev_io_name_get(struct dev_io *dev);
-extern void dev_io_link_type_set(struct dev_io *dev, int link_type);
+extern int dev_io_link_type_set(struct dev_io *dev, int link_type);
 extern bool dev_io_is_netdev(struct dev_io *dev);
 extern bool dev_io_is_pcap(struct dev_io *dev);
 extern void dev_io_close(struct dev_io *dev);