[PATCH v3] kvm tools: Support multiple net devices

[PATCH v3] kvm tools: Support multiple net devices

[Sasha Levin]

This patch adds support for multiple network devices. The command line syntax
changes to the following:

	--network/-n [mode=tap/user/none][,guest_ip=ip][,host_ip=
ip][,guest_mac=mac][,script=file]

Each of the parameters is optional, and the config defaults to a TAP based
networking with a sequential MAC.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
---
 tools/kvm/builtin-run.c |  146 ++++++++++++++++++++++++++++++++------------
 tools/kvm/virtio/net.c  |  157 ++++++++++++++++++++++++++---------------------
 2 files changed, 193 insertions(+), 110 deletions(-)

diff --git a/tools/kvm/builtin-run.c b/tools/kvm/builtin-run.c
index 28dc95a..070b1b6 100644
--- a/tools/kvm/builtin-run.c
+++ b/tools/kvm/builtin-run.c
@@ -87,9 +87,12 @@ static bool sdl;
 static bool balloon;
 static bool using_rootfs;
 static bool custom_rootfs;
+static bool no_net;
 extern bool ioport_debug;
 extern int  active_console;
 extern int  debug_iodelay;
+struct virtio_net_parameters *net_params;
+int num_net_devices;
 
 bool do_debug_print = false;
 
@@ -182,6 +185,89 @@ static int tty_parser(const struct option *opt, const char *arg, int unset)
 	return 0;
 }
 
+static inline void str_to_mac(const char *str, char *mac)
+{
+	sscanf(str, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
+		mac, mac+1, mac+2, mac+3, mac+4, mac+5);
+}
+static int set_net_param(struct virtio_net_parameters *p, const char *param,
+				const char *val)
+{
+	if (strcmp(param, "guest_mac") == 0) {
+		str_to_mac(val, p->guest_mac);
+	} else if (strcmp(param, "mode") == 0) {
+		if (!strncmp(val, "user", 4)) {
+			int i;
+
+			for (i = 0; i < num_net_devices; i++)
+				if (net_params[i].mode == NET_MODE_USER)
+					die("Only one usermode network device allowed at a time");
+			p->mode = NET_MODE_USER;
+		} else if (!strncmp(val, "tap", 3)) {
+			p->mode = NET_MODE_TAP;
+		} else if (!strncmp(val, "none", 4)) {
+			no_net = 1;
+			return -1;
+		} else
+			die("Unkown network mode %s, please use user, tap or none", network);
+	} else if (strcmp(param, "script") == 0) {
+		p->script = val;
+	} else if (strcmp(param, "guest_ip") == 0) {
+		p->guest_ip = val;
+	} else if (strcmp(param, "host_ip") == 0) {
+		p->host_ip = val;
+	}
+
+	return 0;
+}
+
+static int netdev_parser(const struct option *opt, const char *arg, int unset)
+{
+	struct virtio_net_parameters p;
+	char *buf, *cmd = NULL, *cur = NULL;
+	bool on_cmd = true;
+
+	if (arg) {
+		buf = strdup(arg);
+		if (buf == NULL)
+			die("Failed allocating new net buffer");
+		cur = strtok(buf, ",=");
+	}
+
+	p = (struct virtio_net_parameters) {
+		.guest_ip	= DEFAULT_GUEST_ADDR,
+		.host_ip	= DEFAULT_HOST_ADDR,
+		.script		= DEFAULT_SCRIPT,
+		.mode		= NET_MODE_TAP,
+	};
+
+	str_to_mac(DEFAULT_GUEST_MAC, p.guest_mac);
+	p.guest_mac[5] += num_net_devices;
+
+	while (cur) {
+		if (on_cmd) {
+			cmd = cur;
+		} else {
+			if (set_net_param(&p, cmd, cur) < 0)
+				goto done;
+		}
+		on_cmd = !on_cmd;
+
+		cur = strtok(NULL, ",=");
+	};
+
+	num_net_devices++;
+
+	net_params = realloc(net_params, num_net_devices * sizeof(*net_params));
+	if (net_params == NULL)
+		die("Failed adding new network device");
+
+	net_params[num_net_devices - 1] = p;
+
+done:
+	return 0;
+}
+
 static int shmem_parser(const struct option *opt, const char *arg, int unset)
 {
 	const u64 default_size = SHMEM_DEFAULT_SIZE;
@@ -339,18 +425,9 @@ static const struct option options[] = {
 			"Kernel command line arguments"),
 
 	OPT_GROUP("Networking options:"),
-	OPT_STRING('n', "network", &network, "user, tap, none",
-			"Network to use"),
-	OPT_STRING('\0', "host-ip", &host_ip, "a.b.c.d",
-			"Assign this address to the host side networking"),
-	OPT_STRING('\0', "guest-ip", &guest_ip, "a.b.c.d",
-			"Assign this address to the guest side networking"),
-	OPT_STRING('\0', "host-mac", &host_mac, "aa:bb:cc:dd:ee:ff",
-			"Assign this address to the host side NIC"),
-	OPT_STRING('\0', "guest-mac", &guest_mac, "aa:bb:cc:dd:ee:ff",
-			"Assign this address to the guest side NIC"),
-	OPT_STRING('\0', "tapscript", &script, "Script path",
-			 "Assign a script to process created tap device"),
+	OPT_CALLBACK_DEFAULT('n', "network", NULL, "network params",
+		     "Create a new guest NIC",
+		     netdev_parser, NULL),
 
 	OPT_GROUP("BIOS options:"),
 	OPT_INTEGER('\0', "vidmode", &vidmode,
@@ -615,7 +692,6 @@ void kvm_run_help(void)
 
 int kvm_cmd_run(int argc, const char **argv, const char *prefix)
 {
-	struct virtio_net_parameters net_params;
 	static char real_cmdline[2048], default_name[20];
 	struct framebuffer *fb = NULL;
 	unsigned int nr_online_cpus;
@@ -823,32 +899,24 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
 
 	virtio_9p__init(kvm);
 
-	if (strncmp(network, "none", 4)) {
-		net_params.guest_ip = guest_ip;
-		net_params.host_ip = host_ip;
-		net_params.kvm = kvm;
-		net_params.script = script;
-		sscanf(guest_mac, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
-			net_params.guest_mac,
-			net_params.guest_mac+1,
-			net_params.guest_mac+2,
-			net_params.guest_mac+3,
-			net_params.guest_mac+4,
-			net_params.guest_mac+5);
-		sscanf(host_mac, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
-			net_params.host_mac,
-			net_params.host_mac+1,
-			net_params.host_mac+2,
-			net_params.host_mac+3,
-			net_params.host_mac+4,
-			net_params.host_mac+5);
-
-		if (!strncmp(network, "user", 4))
-			net_params.mode = NET_MODE_USER;
-		else if (!strncmp(network, "tap", 3))
-			net_params.mode = NET_MODE_TAP;
-		else
-			die("Unkown network mode %s, please use -network user, tap, none", network);
+	for (i = 0; i < num_net_devices; i++) {
+		net_params[i].kvm = kvm;
+		virtio_net__init(&net_params[i]);
+	}
+
+	if (num_net_devices == 0 && no_net == 0) {
+		struct virtio_net_parameters net_params;
+
+		net_params = (struct virtio_net_parameters) {
+			.guest_ip	= guest_ip,
+			.host_ip	= host_ip,
+			.kvm		= kvm,
+			.script		= script,
+			.mode		= NET_MODE_USER,
+		};
+		str_to_mac(guest_mac, net_params.guest_mac);
+		str_to_mac(host_mac, net_params.host_mac);
+
 		virtio_net__init(&net_params);
 	}
 
diff --git a/tools/kvm/virtio/net.c b/tools/kvm/virtio/net.c
index 4700483..ae23e42 100644
--- a/tools/kvm/virtio/net.c
+++ b/tools/kvm/virtio/net.c
@@ -43,6 +43,7 @@ struct net_dev_operations {
 struct net_dev {
 	pthread_mutex_t			mutex;
 	struct virtio_pci		vpci;
+	struct list_head		list;
 
 	struct virt_queue		vqs[VIRTIO_NET_NUM_QUEUES];
 	struct virtio_net_config	config;
@@ -64,48 +65,41 @@ struct net_dev {
 
 	struct uip_info			info;
 	struct net_dev_operations	*ops;
+	struct kvm			*kvm;
 };
 
-static struct net_dev ndev = {
-	.mutex	= PTHREAD_MUTEX_INITIALIZER,
-
-	.config = {
-		.status			= VIRTIO_NET_S_LINK_UP,
-	},
-	.info = {
-		.buf_nr			= 20,
-	}
-};
+static LIST_HEAD(ndevs);
 
 static void *virtio_net_rx_thread(void *p)
 {
 	struct iovec iov[VIRTIO_NET_QUEUE_SIZE];
 	struct virt_queue *vq;
 	struct kvm *kvm;
+	struct net_dev *ndev = p;
 	u16 out, in;
 	u16 head;
 	int len;
 
-	kvm	= p;
-	vq	= &ndev.vqs[VIRTIO_NET_RX_QUEUE];
+	kvm	= ndev->kvm;
+	vq	= &ndev->vqs[VIRTIO_NET_RX_QUEUE];
 
 	while (1) {
 
-		mutex_lock(&ndev.io_rx_lock);
+		mutex_lock(&ndev->io_rx_lock);
 		if (!virt_queue__available(vq))
-			pthread_cond_wait(&ndev.io_rx_cond, &ndev.io_rx_lock);
-		mutex_unlock(&ndev.io_rx_lock);
+			pthread_cond_wait(&ndev->io_rx_cond, &ndev->io_rx_lock);
+		mutex_unlock(&ndev->io_rx_lock);
 
 		while (virt_queue__available(vq)) {
 
 			head = virt_queue__get_iov(vq, iov, &out, &in, kvm);
 
-			len = ndev.ops->rx(iov, in, &ndev);
+			len = ndev->ops->rx(iov, in, ndev);
 
 			virt_queue__set_used_elem(vq, head, len);
 
 			/* We should interrupt guest right now, otherwise latency is huge. */
-			virtio_pci__signal_vq(kvm, &ndev.vpci, VIRTIO_NET_RX_QUEUE);
+			virtio_pci__signal_vq(kvm, &ndev->vpci, VIRTIO_NET_RX_QUEUE);
 		}
 
 	}
@@ -120,29 +114,30 @@ static void *virtio_net_tx_thread(void *p)
 	struct iovec iov[VIRTIO_NET_QUEUE_SIZE];
 	struct virt_queue *vq;
 	struct kvm *kvm;
+	struct net_dev *ndev = p;
 	u16 out, in;
 	u16 head;
 	int len;
 
-	kvm	= p;
-	vq	= &ndev.vqs[VIRTIO_NET_TX_QUEUE];
+	kvm	= ndev->kvm;
+	vq	= &ndev->vqs[VIRTIO_NET_TX_QUEUE];
 
 	while (1) {
-		mutex_lock(&ndev.io_tx_lock);
+		mutex_lock(&ndev->io_tx_lock);
 		if (!virt_queue__available(vq))
-			pthread_cond_wait(&ndev.io_tx_cond, &ndev.io_tx_lock);
-		mutex_unlock(&ndev.io_tx_lock);
+			pthread_cond_wait(&ndev->io_tx_cond, &ndev->io_tx_lock);
+		mutex_unlock(&ndev->io_tx_lock);
 
 		while (virt_queue__available(vq)) {
 
 			head = virt_queue__get_iov(vq, iov, &out, &in, kvm);
 
-			len = ndev.ops->tx(iov, out, &ndev);
+			len = ndev->ops->tx(iov, out, ndev);
 
 			virt_queue__set_used_elem(vq, head, len);
 		}
 
-		virtio_pci__signal_vq(kvm, &ndev.vpci, VIRTIO_NET_TX_QUEUE);
+		virtio_pci__signal_vq(kvm, &ndev->vpci, VIRTIO_NET_TX_QUEUE);
 	}
 
 	pthread_exit(NULL);
@@ -151,58 +146,58 @@ static void *virtio_net_tx_thread(void *p)
 
 }
 
-static void virtio_net_handle_callback(struct kvm *kvm, u16 queue_index)
+static void virtio_net_handle_callback(struct kvm *kvm, struct net_dev *ndev, int queue)
 {
-	switch (queue_index) {
+	switch (queue) {
 	case VIRTIO_NET_TX_QUEUE:
-		mutex_lock(&ndev.io_tx_lock);
-		pthread_cond_signal(&ndev.io_tx_cond);
-		mutex_unlock(&ndev.io_tx_lock);
+		mutex_lock(&ndev->io_tx_lock);
+		pthread_cond_signal(&ndev->io_tx_cond);
+		mutex_unlock(&ndev->io_tx_lock);
 		break;
 	case VIRTIO_NET_RX_QUEUE:
-		mutex_lock(&ndev.io_rx_lock);
-		pthread_cond_signal(&ndev.io_rx_cond);
-		mutex_unlock(&ndev.io_rx_lock);
+		mutex_lock(&ndev->io_rx_lock);
+		pthread_cond_signal(&ndev->io_rx_cond);
+		mutex_unlock(&ndev->io_rx_lock);
 		break;
 	default:
-		pr_warning("Unknown queue index %u", queue_index);
+		pr_warning("Unknown queue index %u", queue);
 	}
 }
 
-static bool virtio_net__tap_init(const struct virtio_net_parameters *params)
+static bool virtio_net__tap_init(const struct virtio_net_parameters *params,
+					struct net_dev *ndev)
 {
 	int sock = socket(AF_INET, SOCK_STREAM, 0);
 	int pid, status, offload, hdr_len;
 	struct sockaddr_in sin = {0};
 	struct ifreq ifr;
 
-	ndev.tap_fd = open("/dev/net/tun", O_RDWR);
-	if (ndev.tap_fd < 0) {
+	ndev->tap_fd = open("/dev/net/tun", O_RDWR);
+	if (ndev->tap_fd < 0) {
 		pr_warning("Unable to open /dev/net/tun");
 		goto fail;
 	}
 
 	memset(&ifr, 0, sizeof(ifr));
 	ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR;
-	if (ioctl(ndev.tap_fd, TUNSETIFF, &ifr) < 0) {
+	if (ioctl(ndev->tap_fd, TUNSETIFF, &ifr) < 0) {
 		pr_warning("Config tap device error. Are you root?");
 		goto fail;
 	}
 
-	strncpy(ndev.tap_name, ifr.ifr_name, sizeof(ndev.tap_name));
+	strncpy(ndev->tap_name, ifr.ifr_name, sizeof(ndev->tap_name));
 
-	if (ioctl(ndev.tap_fd, TUNSETNOCSUM, 1) < 0) {
+	if (ioctl(ndev->tap_fd, TUNSETNOCSUM, 1) < 0) {
 		pr_warning("Config tap device TUNSETNOCSUM error");
 		goto fail;
 	}
 
 	hdr_len = sizeof(struct virtio_net_hdr);
-	if (ioctl(ndev.tap_fd, TUNSETVNETHDRSZ, &hdr_len) < 0) {
+	if (ioctl(ndev->tap_fd, TUNSETVNETHDRSZ, &hdr_len) < 0)
 		pr_warning("Config tap device TUNSETVNETHDRSZ error");
-	}
 
 	offload = TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 | TUN_F_UFO;
-	if (ioctl(ndev.tap_fd, TUNSETOFFLOAD, offload) < 0) {
+	if (ioctl(ndev->tap_fd, TUNSETOFFLOAD, offload) < 0) {
 		pr_warning("Config tap device TUNSETOFFLOAD error");
 		goto fail;
 	}
@@ -210,7 +205,7 @@ static bool virtio_net__tap_init(const struct virtio_net_parameters *params)
 	if (strcmp(params->script, "none")) {
 		pid = fork();
 		if (pid == 0) {
-			execl(params->script, params->script, ndev.tap_name, NULL);
+			execl(params->script, params->script, ndev->tap_name, NULL);
 			_exit(1);
 		} else {
 			waitpid(pid, &status, 0);
@@ -221,7 +216,7 @@ static bool virtio_net__tap_init(const struct virtio_net_parameters *params)
 		}
 	} else {
 		memset(&ifr, 0, sizeof(ifr));
-		strncpy(ifr.ifr_name, ndev.tap_name, sizeof(ndev.tap_name));
+		strncpy(ifr.ifr_name, ndev->tap_name, sizeof(ndev->tap_name));
 		sin.sin_addr.s_addr = inet_addr(params->host_ip);
 		memcpy(&(ifr.ifr_addr), &sin, sizeof(ifr.ifr_addr));
 		ifr.ifr_addr.sa_family = AF_INET;
@@ -232,7 +227,7 @@ static bool virtio_net__tap_init(const struct virtio_net_parameters *params)
 	}
 
 	memset(&ifr, 0, sizeof(ifr));
-	strncpy(ifr.ifr_name, ndev.tap_name, sizeof(ndev.tap_name));
+	strncpy(ifr.ifr_name, ndev->tap_name, sizeof(ndev->tap_name));
 	ioctl(sock, SIOCGIFFLAGS, &ifr);
 	ifr.ifr_flags |= IFF_UP | IFF_RUNNING;
 	if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0)
@@ -245,22 +240,22 @@ static bool virtio_net__tap_init(const struct virtio_net_parameters *params)
 fail:
 	if (sock >= 0)
 		close(sock);
-	if (ndev.tap_fd >= 0)
-		close(ndev.tap_fd);
+	if (ndev->tap_fd >= 0)
+		close(ndev->tap_fd);
 
 	return 0;
 }
 
-static void virtio_net__io_thread_init(struct kvm *kvm)
+static void virtio_net__io_thread_init(struct kvm *kvm, struct net_dev *ndev)
 {
-	pthread_mutex_init(&ndev.io_rx_lock, NULL);
-	pthread_cond_init(&ndev.io_tx_cond, NULL);
+	pthread_mutex_init(&ndev->io_rx_lock, NULL);
+	pthread_cond_init(&ndev->io_tx_cond, NULL);
 
-	pthread_mutex_init(&ndev.io_rx_lock, NULL);
-	pthread_cond_init(&ndev.io_tx_cond, NULL);
+	pthread_mutex_init(&ndev->io_rx_lock, NULL);
+	pthread_cond_init(&ndev->io_tx_cond, NULL);
 
-	pthread_create(&ndev.io_rx_thread, NULL, virtio_net_rx_thread, (void *)kvm);
-	pthread_create(&ndev.io_tx_thread, NULL, virtio_net_tx_thread, (void *)kvm);
+	pthread_create(&ndev->io_rx_thread, NULL, virtio_net_rx_thread, ndev);
+	pthread_create(&ndev->io_tx_thread, NULL, virtio_net_tx_thread, ndev);
 }
 
 static inline int tap_ops_tx(struct iovec *iov, u16 out, struct net_dev *ndev)
@@ -345,7 +340,9 @@ static int init_vq(struct kvm *kvm, void *dev, u32 vq, u32 pfn)
 
 static int notify_vq(struct kvm *kvm, void *dev, u32 vq)
 {
-	virtio_net_handle_callback(kvm, vq);
+	struct net_dev *ndev = dev;
+
+	virtio_net_handle_callback(kvm, ndev, vq);
 
 	return 0;
 }
@@ -365,27 +362,45 @@ static int get_size_vq(struct kvm *kvm, void *dev, u32 vq)
 void virtio_net__init(const struct virtio_net_parameters *params)
 {
 	int i;
+	struct net_dev *ndev;
+
+	if (!params)
+		return;
+
+	ndev = calloc(1, sizeof(struct net_dev));
+	if (ndev == NULL)
+		die("Failed allocating ndev");
+
+	list_add_tail(&ndev->list, &ndevs);
+
+	ndev->kvm = params->kvm;
+
+	mutex_init(&ndev->mutex);
+	ndev->config.status = VIRTIO_NET_S_LINK_UP;
 
 	for (i = 0 ; i < 6 ; i++) {
-		ndev.config.mac[i]		= params->guest_mac[i];
-		ndev.info.guest_mac.addr[i]	= params->guest_mac[i];
-		ndev.info.host_mac.addr[i]	= params->host_mac[i];
+		ndev->config.mac[i]		= params->guest_mac[i];
+		ndev->info.guest_mac.addr[i]	= params->guest_mac[i];
+		ndev->info.host_mac.addr[i]	= params->host_mac[i];
 	}
 
-	ndev.mode = params->mode;
-	if (ndev.mode == NET_MODE_TAP) {
-		virtio_net__tap_init(params);
-		ndev.ops = &tap_ops;
+	ndev->mode = params->mode;
+	if (ndev->mode == NET_MODE_TAP) {
+		if (!virtio_net__tap_init(params, ndev))
+			die_perror("You have requested a TAP device, but creation of one has"
+					"failed because:");
+		ndev->ops = &tap_ops;
 	} else {
-		ndev.info.host_ip		= ntohl(inet_addr(params->host_ip));
-		ndev.info.guest_ip		= ntohl(inet_addr(params->guest_ip));
-		ndev.info.guest_netmask		= ntohl(inet_addr("255.255.255.0"));
-		uip_init(&ndev.info);
-		ndev.ops = &uip_ops;
+		ndev->info.host_ip		= ntohl(inet_addr(params->host_ip));
+		ndev->info.guest_ip		= ntohl(inet_addr(params->guest_ip));
+		ndev->info.guest_netmask	= ntohl(inet_addr("255.255.255.0"));
+		ndev->info.buf_nr		= 20,
+		uip_init(&ndev->info);
+		ndev->ops = &uip_ops;
 	}
 
-	virtio_pci__init(kvm, &ndev.vpci, &ndev, PCI_DEVICE_ID_VIRTIO_NET, VIRTIO_ID_NET);
-	ndev.vpci.ops = (struct virtio_pci_ops) {
+	virtio_pci__init(kvm, &ndev->vpci, ndev, PCI_DEVICE_ID_VIRTIO_NET, VIRTIO_ID_NET);
+	ndev->vpci.ops = (struct virtio_pci_ops) {
 		.set_config		= set_config,
 		.get_config		= get_config,
 		.get_host_features	= get_host_features,
@@ -396,9 +411,9 @@ void virtio_net__init(const struct virtio_net_parameters *params)
 		.get_size_vq		= get_size_vq,
 	};
 
-	virtio_net__io_thread_init(params->kvm);
+	virtio_net__io_thread_init(params->kvm, ndev);
 
-	ndev.compat_id = compat__add_message("virtio-net device was not detected",
+	ndev->compat_id = compat__add_message("virtio-net device was not detected",
 						"While you have requested a virtio-net device, "
 						"the guest kernel didn't seem to detect it.\n"
 						"Please make sure that the kernel was compiled "
-- 
1.7.6.1

Re: [PATCH v3] kvm tools: Support multiple net devices

[Asias He]

On 09/27/2011 01:44 AM, Sasha Levin wrote:
> This patch adds support for multiple network devices. The command line syntax
> changes to the following:
> 
> 	--network/-n [mode=tap/user/none][,guest_ip=ip][,host_ip=
> ip][,guest_mac=mac][,script=file]
> 
> Each of the parameters is optional, and the config defaults to a TAP based
> networking with a sequential MAC.
> 
> Signed-off-by: Sasha Levin <levinsasha928@gmail.com>

Acked-by: Asias He <asias.hejun@gmail.com>

-- 
Asias He

Re: [PATCH v3] kvm tools: Support multiple net devices

[Ingo Molnar]

* Sasha Levin <levinsasha928@gmail.com> wrote:

> --- a/tools/kvm/builtin-run.c
> +++ b/tools/kvm/builtin-run.c
> @@ -87,9 +87,12 @@ static bool sdl;
>  static bool balloon;
>  static bool using_rootfs;
>  static bool custom_rootfs;
> +static bool no_net;
>  extern bool ioport_debug;
>  extern int  active_console;
>  extern int  debug_iodelay;
> +struct virtio_net_parameters *net_params;
> +int num_net_devices;

Just a stylistic nit-pick: this variable definition section looks 
pretty ugly. Those externs should be in a header and in any case 
different types of lines should generally not be mixed without at 
least a newline between them.

> +static int set_net_param(struct virtio_net_parameters *p, const char *param,
> +				const char *val)


Naming nit: 'struct virtio_net_params' is shorter by 4 chars and just 
as expressive.

> +	char *buf, *cmd = NULL, *cur = NULL;
> +	bool on_cmd = true;
> +
> +	if (arg) {
> +		buf = strdup(arg);
> +		if (buf == NULL)
> +			die("Failed allocating new net buffer");
> +		cur = strtok(buf, ",=");
> +	}
> +
> +	p = (struct virtio_net_parameters) {
> +		.guest_ip	= DEFAULT_GUEST_ADDR,
> +		.host_ip	= DEFAULT_HOST_ADDR,
> +		.script		= DEFAULT_SCRIPT,
> +		.mode		= NET_MODE_TAP,
> +	};
> +
> +	str_to_mac(DEFAULT_GUEST_MAC, p.guest_mac);
> +	p.guest_mac[5] += num_net_devices;
> +
> +	while (cur) {
> +		if (on_cmd) {
> +			cmd = cur;
> +		} else {
> +			if (set_net_param(&p, cmd, cur) < 0)
> +				goto done;
> +		}
> +		on_cmd = !on_cmd;
> +
> +		cur = strtok(NULL, ",=");
> +	};
> +
> +	num_net_devices++;
> +
> +	net_params = realloc(net_params, num_net_devices * sizeof(*net_params));
> +	if (net_params == NULL)
> +		die("Failed adding new network device");
> +
> +	net_params[num_net_devices - 1] = p;
> +
> +done:
> +	return 0;
> +}

Isn't 'buf' leaked here?

Patch looks good otherwise.

Thanks,

	Ingo