um: Migrate pcap to vector IO

From: Anton Ivanov <anton.ivanov@cambridgegreys.com>

Migrates UML PCAP driver to the new vector IO network backend.

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
---
 arch/um/drivers/Makefile          |   4 +-
 arch/um/drivers/net_kern.c        |  33 ++++++-
 arch/um/drivers/pcap_kern.c       | 113 -----------------------
 arch/um/drivers/pcap_user.c       | 144 +++++++-----------------------
 arch/um/drivers/pcap_user.h       |  21 -----
 arch/um/drivers/vector_kern.c     | 100 +++++++++++++++++++--
 arch/um/drivers/vector_kern.h     |   3 -
 arch/um/drivers/vector_user.c     |  12 +++
 arch/um/drivers/vector_user.h     |   1 -
 arch/um/include/shared/net_kern.h |   2 +-
 arch/um/include/shared/net_user.h |   2 +
 11 files changed, 173 insertions(+), 262 deletions(-)
 delete mode 100644 arch/um/drivers/pcap_kern.c
 delete mode 100644 arch/um/drivers/pcap_user.h

On 13/12/2019 10:08, anton.ivanov@cambridgegreys.com wrote:
> From: Anton Ivanov <anton.ivanov@cambridgegreys.com>
> 
> Migrates UML PCAP driver to the new vector IO network backend.
> 
> Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
> ---
>   arch/um/drivers/Makefile          |   4 +-
>   arch/um/drivers/net_kern.c        |  33 ++++++-
>   arch/um/drivers/pcap_kern.c       | 113 -----------------------
>   arch/um/drivers/pcap_user.c       | 144 +++++++-----------------------
>   arch/um/drivers/pcap_user.h       |  21 -----
>   arch/um/drivers/vector_kern.c     | 100 +++++++++++++++++++--
>   arch/um/drivers/vector_kern.h     |   3 -
>   arch/um/drivers/vector_user.c     |  12 +++
>   arch/um/drivers/vector_user.h     |   1 -
>   arch/um/include/shared/net_kern.h |   2 +-
>   arch/um/include/shared/net_user.h |   2 +
>   11 files changed, 173 insertions(+), 262 deletions(-)
>   delete mode 100644 arch/um/drivers/pcap_kern.c
>   delete mode 100644 arch/um/drivers/pcap_user.h
> 
> diff --git a/arch/um/drivers/Makefile b/arch/um/drivers/Makefile
> index a290821e355c..ea449dc72236 100644
> --- a/arch/um/drivers/Makefile
> +++ b/arch/um/drivers/Makefile
> @@ -22,9 +22,9 @@ LDFLAGS_pcap.o := -r $(shell $(CC) $(KBUILD_CFLAGS) -print-file-name=libpcap.a)
>   
>   LDFLAGS_vde.o := -r $(shell $(CC) $(CFLAGS) -print-file-name=libvdeplug.a)
>   
> -targets := pcap_kern.o pcap_user.o vde_kern.o vde_user.o
> +targets := pcap_user.o vde_kern.o vde_user.o
>   
> -$(obj)/pcap.o: $(obj)/pcap_kern.o $(obj)/pcap_user.o
> +$(obj)/pcap.o: $(obj)/pcap_user.o
>   	$(LD) -r -dp -o $@ $^ $(ld_flags)
>   
>   $(obj)/vde.o: $(obj)/vde_kern.o $(obj)/vde_user.o
> diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
> index 327b728f7244..7df7344f2194 100644
> --- a/arch/um/drivers/net_kern.c
> +++ b/arch/um/drivers/net_kern.c
> @@ -42,6 +42,9 @@ static DEFINE_SPINLOCK(drop_lock);
>   static struct sk_buff *drop_skb;
>   static int drop_max;
>   
> +static const char *migrated_to_vector = {"pcap"};
> +#define MAX_MIGRATED 1
> +
>   static int update_drop_skb(int max)
>   {
>   	struct sk_buff *new;
> @@ -581,6 +584,26 @@ static int check_transport(struct transport *transport, char *eth, int n,
>   	}
>   	return 1;
>   }
> +static int register_compat(void)
> +{
> +	struct list_head *ele, *next;
> +	struct eth_init *eth;
> +	int compat;
> +
> +	list_for_each_safe(ele, next, &eth_cmd_line) {
> +		eth = list_entry(ele, struct eth_init, list);
> +		for (compat = 0; compat < MAX_MIGRATED; compat++) {
> +			if (strncmp(eth->init, &migrated_to_vector[compat], strlen(&migrated_to_vector[compat])) == 0) {
> +				vector_compat_eth_configure(eth->init, eth->index);
> +				list_del(&eth->list);
> +				continue;
> +			}
> +		}
> +	}
> +	return 0;
> +}
> +
> +late_initcall(register_compat);
>   
>   void register_transport(struct transport *new)
>   {
> @@ -597,8 +620,9 @@ void register_transport(struct transport *new)
>   
>   	list_for_each_safe(ele, next, &eth_cmd_line) {
>   		eth = list_entry(ele, struct eth_init, list);
> +
>   		match = check_transport(new, eth->init, eth->index, &init,
> -					&mac, GFP_KERNEL);
> +				&mac, GFP_KERNEL);
>   		if (!match)
>   			continue;
>   		else if (init != NULL) {
> @@ -615,7 +639,12 @@ static int eth_setup_common(char *str, int index)
>   	struct transport *transport;
>   	void *init;
>   	char *mac = NULL;
> -	int found = 0;
> +	int found = 0, compat;
> +
> +	for (compat = 0; compat < MAX_MIGRATED; compat++) {
> +		if (strncmp(str, &migrated_to_vector[compat], strlen(&migrated_to_vector[compat])) == 0)
> +			return vector_compat_eth_configure(str, index);
> +	}
>   
>   	spin_lock(&transports_lock);
>   	list_for_each(ele, &transports) {
> diff --git a/arch/um/drivers/pcap_kern.c b/arch/um/drivers/pcap_kern.c
> deleted file mode 100644
> index cfe4cb17694c..000000000000
> --- a/arch/um/drivers/pcap_kern.c
> +++ /dev/null
> @@ -1,113 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -/*
> - * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
> - */
> -
> -#include <linux/init.h>
> -#include <linux/netdevice.h>
> -#include <net_kern.h>
> -#include "pcap_user.h"
> -
> -struct pcap_init {
> -	char *host_if;
> -	int promisc;
> -	int optimize;
> -	char *filter;
> -};
> -
> -void pcap_init(struct net_device *dev, void *data)
> -{
> -	struct uml_net_private *pri;
> -	struct pcap_data *ppri;
> -	struct pcap_init *init = data;
> -
> -	pri = netdev_priv(dev);
> -	ppri = (struct pcap_data *) pri->user;
> -	ppri->host_if = init->host_if;
> -	ppri->promisc = init->promisc;
> -	ppri->optimize = init->optimize;
> -	ppri->filter = init->filter;
> -
> -	printk("pcap backend, host interface %s\n", ppri->host_if);
> -}
> -
> -static int pcap_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
> -{
> -	return pcap_user_read(fd, skb_mac_header(skb),
> -			      skb->dev->mtu + ETH_HEADER_OTHER,
> -			      (struct pcap_data *) &lp->user);
> -}
> -
> -static int pcap_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
> -{
> -	return -EPERM;
> -}
> -
> -static const struct net_kern_info pcap_kern_info = {
> -	.init			= pcap_init,
> -	.protocol		= eth_protocol,
> -	.read			= pcap_read,
> -	.write			= pcap_write,
> -};
> -
> -int pcap_setup(char *str, char **mac_out, void *data)
> -{
> -	struct pcap_init *init = data;
> -	char *remain, *host_if = NULL, *options[2] = { NULL, NULL };
> -	int i;
> -
> -	*init = ((struct pcap_init)
> -		{ .host_if 	= "eth0",
> -		  .promisc 	= 1,
> -		  .optimize 	= 0,
> -		  .filter 	= NULL });
> -
> -	remain = split_if_spec(str, &host_if, &init->filter,
> -			       &options[0], &options[1], mac_out, NULL);
> -	if (remain != NULL) {
> -		printk(KERN_ERR "pcap_setup - Extra garbage on "
> -		       "specification : '%s'\n", remain);
> -		return 0;
> -	}
> -
> -	if (host_if != NULL)
> -		init->host_if = host_if;
> -
> -	for (i = 0; i < ARRAY_SIZE(options); i++) {
> -		if (options[i] == NULL)
> -			continue;
> -		if (!strcmp(options[i], "promisc"))
> -			init->promisc = 1;
> -		else if (!strcmp(options[i], "nopromisc"))
> -			init->promisc = 0;
> -		else if (!strcmp(options[i], "optimize"))
> -			init->optimize = 1;
> -		else if (!strcmp(options[i], "nooptimize"))
> -			init->optimize = 0;
> -		else {
> -			printk(KERN_ERR "pcap_setup : bad option - '%s'\n",
> -			       options[i]);
> -			return 0;
> -		}
> -	}
> -
> -	return 1;
> -}
> -
> -static struct transport pcap_transport = {
> -	.list 		= LIST_HEAD_INIT(pcap_transport.list),
> -	.name 		= "pcap",
> -	.setup  	= pcap_setup,
> -	.user 		= &pcap_user_info,
> -	.kern 		= &pcap_kern_info,
> -	.private_size 	= sizeof(struct pcap_data),
> -	.setup_size 	= sizeof(struct pcap_init),
> -};
> -
> -static int register_pcap(void)
> -{
> -	register_transport(&pcap_transport);
> -	return 0;
> -}
> -
> -late_initcall(register_pcap);
> diff --git a/arch/um/drivers/pcap_user.c b/arch/um/drivers/pcap_user.c
> index bbd20638788a..0b49a2e76c9a 100644
> --- a/arch/um/drivers/pcap_user.c
> +++ b/arch/um/drivers/pcap_user.c
> @@ -8,130 +8,50 @@
>   #include <string.h>
>   #include <asm/types.h>
>   #include <net_user.h>
> -#include "pcap_user.h"
> +#include <sys/socket.h>
> +#include <linux/filter.h>
>   #include <um_malloc.h>
>   
> -#define PCAP_FD(p) (*(int *)(p))
> -
> -static int pcap_user_init(void *data, void *dev)
> +void *uml_vector_compile_pcap(char *filter, int optimize)
>   {
> -	struct pcap_data *pri = data;
> -	pcap_t *p;
> -	char errors[PCAP_ERRBUF_SIZE];
> -
> -	p = pcap_open_live(pri->host_if, ETH_MAX_PACKET + ETH_HEADER_OTHER,
> -			   pri->promisc, 0, errors);
> -	if (p == NULL) {
> -		printk(UM_KERN_ERR "pcap_user_init : pcap_open_live failed - "
> -		       "'%s'\n", errors);
> -		return -EINVAL;
> -	}
> +	struct sock_fprog *bpf_prog = NULL;
> +	struct bpf_program *pcap_prog = NULL;
>   
> -	pri->dev = dev;
> -	pri->pcap = p;
> -	return 0;
> -}
> -
> -static int pcap_open(void *data)
> -{
> -	struct pcap_data *pri = data;
> -	__u32 netmask;
> -	int err;
> +	if (filter == NULL)
> +		return NULL;
>   
> -	if (pri->pcap == NULL)
> -		return -ENODEV;
> +	pcap_prog = uml_kmalloc(sizeof(struct bpf_program), UM_GFP_KERNEL);
> +	if (!pcap_prog)
> +		goto pcap_failed;
>   
> -	if (pri->filter != NULL) {
> -		err = dev_netmask(pri->dev, &netmask);
> -		if (err < 0) {
> -			printk(UM_KERN_ERR "pcap_open : dev_netmask failed\n");
> -			return -EIO;
> -		}
> +	bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL);
> +	if (!bpf_prog)
> +		goto pcap_failed;
> +	else
> +		bpf_prog->filter = NULL;
>   
> -		pri->compiled = uml_kmalloc(sizeof(struct bpf_program),
> -					UM_GFP_KERNEL);
> -		if (pri->compiled == NULL) {
> -			printk(UM_KERN_ERR "pcap_open : kmalloc failed\n");
> -			return -ENOMEM;
> -		}
> -
> -		err = pcap_compile(pri->pcap,
> -				   (struct bpf_program *) pri->compiled,
> -				   pri->filter, pri->optimize, netmask);
> -		if (err < 0) {
> -			printk(UM_KERN_ERR "pcap_open : pcap_compile failed - "
> -			       "'%s'\n", pcap_geterr(pri->pcap));
> -			goto out;
> -		}
> -
> -		err = pcap_setfilter(pri->pcap, pri->compiled);
> -		if (err < 0) {
> -			printk(UM_KERN_ERR "pcap_open : pcap_setfilter "
> -			       "failed - '%s'\n", pcap_geterr(pri->pcap));
> -			goto out;
> -		}
> +	if (pcap_compile_nopcap((1 < 16) - 1, DLT_EN10MB, pcap_prog, filter, optimize, PCAP_NETMASK_UNKNOWN)) {
> +		printk(KERN_ERR "Failed to compile filter");
> +		goto pcap_failed;
>   	}
>   
> -	return PCAP_FD(pri->pcap);
> -
> - out:
> -	kfree(pri->compiled);
> -	return -EIO;
> -}
> -
> -static void pcap_remove(void *data)
> -{
> -	struct pcap_data *pri = data;
> -
> -	if (pri->compiled != NULL)
> -		pcap_freecode(pri->compiled);
> -
> -	if (pri->pcap != NULL)
> -		pcap_close(pri->pcap);
> -}
> -
> -struct pcap_handler_data {
> -	char *buffer;
> -	int len;
> -};
> +	bpf_prog->filter = uml_kmalloc(pcap_prog->bf_len * sizeof(struct bpf_insn), UM_GFP_KERNEL);
>   
> -static void handler(u_char *data, const struct pcap_pkthdr *header,
> -		    const u_char *packet)
> -{
> -	int len;
> +	if (bpf_prog->filter == NULL) {
> +		printk(KERN_ERR "Failed to allocate bpf buffer");
> +		pcap_freecode(pcap_prog);
> +		goto pcap_failed;
> +	}
> +	bpf_prog->len = pcap_prog->bf_len;
> +	memcpy(bpf_prog->filter, pcap_prog->bf_insns, pcap_prog->bf_len * sizeof(struct bpf_insn));
>   
> -	struct pcap_handler_data *hdata = (struct pcap_handler_data *) data;
> +	pcap_freecode(pcap_prog);
> +	return bpf_prog;
>   
> -	len = hdata->len < header->caplen ? hdata->len : header->caplen;
> -	memcpy(hdata->buffer, packet, len);
> -	hdata->len = len;
> +pcap_failed:
> +	kfree(pcap_prog);
> +	kfree(bpf_prog);
> +	return NULL;
>   }
>   
> -int pcap_user_read(int fd, void *buffer, int len, struct pcap_data *pri)
> -{
> -	struct pcap_handler_data hdata = ((struct pcap_handler_data)
> -		                          { .buffer  	= buffer,
> -					    .len 	= len });
> -	int n;
> -
> -	n = pcap_dispatch(pri->pcap, 1, handler, (u_char *) &hdata);
> -	if (n < 0) {
> -		printk(UM_KERN_ERR "pcap_dispatch failed - %s\n",
> -		       pcap_geterr(pri->pcap));
> -		return -EIO;
> -	}
> -	else if (n == 0)
> -		return 0;
> -	return hdata.len;
> -}
>   
> -const struct net_user_info pcap_user_info = {
> -	.init		= pcap_user_init,
> -	.open		= pcap_open,
> -	.close	 	= NULL,
> -	.remove	 	= pcap_remove,
> -	.add_address	= NULL,
> -	.delete_address = NULL,
> -	.mtu		= ETH_MAX_PACKET,
> -	.max_packet	= ETH_MAX_PACKET + ETH_HEADER_OTHER,
> -};
> diff --git a/arch/um/drivers/pcap_user.h b/arch/um/drivers/pcap_user.h
> deleted file mode 100644
> index 216246f5f09b..000000000000
> --- a/arch/um/drivers/pcap_user.h
> +++ /dev/null
> @@ -1,21 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -/*
> - * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
> - */
> -
> -#include <net_user.h>
> -
> -struct pcap_data {
> -	char *host_if;
> -	int promisc;
> -	int optimize;
> -	char *filter;
> -	void *compiled;
> -	void *pcap;
> -	void *dev;
> -};
> -
> -extern const struct net_user_info pcap_user_info;
> -
> -extern int pcap_user_read(int fd, void *buf, int len, struct pcap_data *pri);
> -
> diff --git a/arch/um/drivers/vector_kern.c b/arch/um/drivers/vector_kern.c
> index 92617e16829e..933adf2009dc 100644
> --- a/arch/um/drivers/vector_kern.c
> +++ b/arch/um/drivers/vector_kern.c
> @@ -28,6 +28,7 @@
>   #include <irq_kern.h>
>   #include <irq_user.h>
>   #include <net_kern.h>
> +#include <net_user.h>
>   #include <os.h>
>   #include "mconsole_kern.h"
>   #include "vector_user.h"
> @@ -46,6 +47,7 @@
>   
>   
>   #define DRIVER_NAME "uml-vector"
> +#define DRIVER_CNAME "uml-vector-compat"
>   #define DRIVER_VERSION "01"
>   struct vector_cmd_line_arg {
>   	struct list_head list;
> @@ -68,7 +70,7 @@ static LIST_HEAD(vector_devices);
>   
>   static int driver_registered;
>   
> -static void vector_eth_configure(int n, struct arglist *def);
> +static void vector_eth_configure(int n, struct arglist *def, bool compat);
>   
>   /* Argument accessors to set variables (and/or set default values)
>    * mtu, buffer sizing, default headroom, etc
> @@ -101,6 +103,7 @@ static const struct {
>   };
>   
>   #define VECTOR_NUM_STATS	ARRAY_SIZE(ethtool_stats_keys)
> +#define MAX_COMPAT_ARG 256
>   
>   static void vector_reset_stats(struct vector_private *vp)
>   {
> @@ -131,11 +134,28 @@ static int get_mtu(struct arglist *def)
>   	return ETH_MAX_PACKET;
>   }
>   
> +static int get_optimize(struct arglist *def)
> +{
> +	char *opt = uml_vector_fetch_arg(def, "optimize");
> +	long result;
> +
> +	if (opt != NULL) {
> +		if (kstrtoul(opt, 10, &result) == 0)
> +			return result;
> +	}
> +	return 0;
> +}
> +
>   static char *get_bpf_file(struct arglist *def)
>   {
>   	return uml_vector_fetch_arg(def, "bpffile");
>   }
>   
> +static char *get_pcap_filter(struct arglist *def)
> +{
> +	return uml_vector_fetch_arg(def, "filter");
> +}
> +
>   static bool get_bpf_flash(struct arglist *def)
>   {
>   	char *allow = uml_vector_fetch_arg(def, "bpfflash");
> @@ -772,7 +792,7 @@ static int vector_config(char *str, char **error_out)
>   		return -EINVAL;
>   	}
>   
> -	vector_eth_configure(n, parsed);
> +	vector_eth_configure(n, parsed, false);
>   	return 0;
>   }
>   
> @@ -1225,7 +1245,14 @@ static int vector_net_open(struct net_device *dev)
>   	vp->opened = true;
>   	spin_unlock_irqrestore(&vp->lock, flags);
>   
> -	vp->bpf = uml_vector_user_bpf(get_bpf_file(vp->parsed));
> +#ifdef CONFIG_UML_NET_PCAP
> +	vp->bpf = uml_vector_compile_pcap(get_pcap_filter(vp->parsed), get_optimize(vp->parsed));
> +#else
> +	vp->bpf = NULL;
> +#endif
> +
> +	if (!vp->bpf)
> +		vp->bpf = uml_vector_user_bpf(get_bpf_file(vp->parsed));
>   
>   	vp->fds = uml_vector_user_open(vp->unit, vp->parsed);
>   
> @@ -1547,7 +1574,8 @@ static void vector_timer_expire(struct timer_list *t)
>   
>   static void vector_eth_configure(
>   		int n,
> -		struct arglist *def
> +		struct arglist *def,
> +		bool compat
>   	)
>   {
>   	struct vector_device *device;
> @@ -1577,7 +1605,10 @@ static void vector_eth_configure(
>   	 * netdevice, that is OK, register_netdev{,ice}() will notice this
>   	 * and fail.
>   	 */
> -	snprintf(dev->name, sizeof(dev->name), "vec%d", n);
> +	if (compat)
> +		snprintf(dev->name, sizeof(dev->name), "eth%d", n);
> +	else
> +		snprintf(dev->name, sizeof(dev->name), "vec%d", n);
>   	uml_net_setup_etheraddr(dev, uml_vector_fetch_arg(def, "mac"));
>   	vp = netdev_priv(dev);
>   
> @@ -1587,7 +1618,10 @@ static void vector_eth_configure(
>   		driver_registered = 1;
>   	}
>   	device->pdev.id = n;
> -	device->pdev.name = DRIVER_NAME;
> +	if (compat)
> +		device->pdev.name = DRIVER_CNAME;
> +	else
> +		device->pdev.name = DRIVER_NAME;
>   	device->pdev.dev.release = vector_device_release;
>   	dev_set_drvdata(&device->pdev.dev, device);
>   	if (platform_device_register(&device->pdev))
> @@ -1660,7 +1694,59 @@ static void vector_eth_configure(
>   	kfree(device);
>   }
>   
> +int vector_compat_eth_configure(char *str, int index)
> +{
> +	char *newargs, *tempargs;
> +	char *remain;
> +	int do_compat = 0;
> +	struct arglist *parsed;
> +	newargs = kmalloc(GFP_KERNEL, MAX_COMPAT_ARG);
> +	if (!newargs)
> +		return -ENOMEM;
> +	tempargs = kmalloc(GFP_KERNEL, MAX_COMPAT_ARG);
> +	if (!tempargs) {
> +		kfree(newargs);
> +		return -ENOMEM;
> +	}
> +	if (strncmp(str, "pcap", strlen("pcap")) == 0) {
> +		char *ifname = NULL, *filter = NULL, *transport = NULL, *mac = NULL;
> +		char *options[2] = { NULL, NULL};
> +
> +		remain = split_if_spec(str, &transport, &ifname, &filter,
> +			       &options[0], &options[1], &mac, NULL);
> +
> +		if ((mac != NULL) && strlen(mac) > 0)
> +			snprintf(tempargs, MAX_COMPAT_ARG, "transport=raw,ifname=%s,mac=%s", ifname, mac);
> +		else
> +			snprintf(tempargs, MAX_COMPAT_ARG, "transport=raw,ifname=%s", ifname);
> +
> +		strcpy(newargs, tempargs);
> +
> +		if (filter != NULL) {
> +			snprintf(tempargs, MAX_COMPAT_ARG, "%s,filter=%s", newargs, filter);
> +			strcpy(newargs, tempargs);
> +		}
>   
> +		if (options[0] != NULL) {
> +			snprintf(tempargs, MAX_COMPAT_ARG, "%s,%s=1", newargs, options[0]);
> +			strcpy(newargs, tempargs);
> +		}
> +		if (options[1] != NULL) {
> +			snprintf(tempargs, MAX_COMPAT_ARG, "%s,%s=1", newargs, options[1]);
> +			strcpy(newargs, tempargs);
> +		}
> +		do_compat = 1;
> +
> +	}
> +	if (do_compat) {
> +		parsed = uml_parse_vector_ifspec(newargs);
> +		vector_eth_configure(index, parsed, true);
> +	} else
> +		kfree(newargs);
> +
> +	kfree(tempargs);
> +	return 0;
> +}
>   
>   
>   /*
> @@ -1677,7 +1763,7 @@ static int __init vector_init(void)
>   		def = list_entry(ele, struct vector_cmd_line_arg, list);
>   		parsed = uml_parse_vector_ifspec(def->arguments);
>   		if (parsed != NULL)
> -			vector_eth_configure(def->unit, parsed);
> +			vector_eth_configure(def->unit, parsed, false);
>   	}
>   	return 0;
>   }
> diff --git a/arch/um/drivers/vector_kern.h b/arch/um/drivers/vector_kern.h
> index d0159082faf0..e643423dfc2f 100644
> --- a/arch/um/drivers/vector_kern.h
> +++ b/arch/um/drivers/vector_kern.h
> @@ -31,9 +31,6 @@
>   #define VECTOR_QDISC_BYPASS (1 << 3)
>   #define VECTOR_BPF_FLASH (1 << 4)
>   
> -#define ETH_MAX_PACKET 1500
> -#define ETH_HEADER_OTHER 32 /* just in case someone decides to go mad on QnQ */
> -
>   #define MAX_FILTER_PROG (2 << 16)
>   
>   struct vector_queue {
> diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
> index ddcd917be0af..c8a11df080d2 100644
> --- a/arch/um/drivers/vector_user.c
> +++ b/arch/um/drivers/vector_user.c
> @@ -367,6 +367,17 @@ static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
>   		err = -errno;
>   		goto raw_cleanup;
>   	}
> +
> +	if (uml_vector_fetch_arg(ifspec, "promisc")) {
> +		struct ifreq ifopts;
> +
> +		memset(&ifopts, 0, sizeof(struct ifreq));
> +		strncpy(ifopts.ifr_name, iface, IFNAMSIZ-1);
> +		ioctl(rxfd, SIOCGIFFLAGS, &ifopts);
> +		ifopts.ifr_flags |= IFF_PROMISC;
> +		ioctl(rxfd, SIOCSIFFLAGS, &ifopts);
> +	}
> +
>   	txfd = create_raw_fd(iface, 0, ETH_P_IP); /* Turn off RX on this fd */
>   	if (txfd == -1) {
>   		err = -errno;
> @@ -764,3 +775,4 @@ void *uml_vector_user_bpf(char *filename)
>   	kfree(bpf_prog);
>   	return NULL;
>   }
> +
> diff --git a/arch/um/drivers/vector_user.h b/arch/um/drivers/vector_user.h
> index 91f35b266aba..a4acfebd28d5 100644
> --- a/arch/um/drivers/vector_user.h
> +++ b/arch/um/drivers/vector_user.h
> @@ -105,5 +105,4 @@ extern bool uml_raw_enable_qdisc_bypass(int fd);
>   extern bool uml_raw_enable_vnet_headers(int fd);
>   extern bool uml_tap_enable_vnet_headers(int fd);
>   
> -
>   #endif
> diff --git a/arch/um/include/shared/net_kern.h b/arch/um/include/shared/net_kern.h
> index a87be13c5b87..f9389a2ec2d8 100644
> --- a/arch/um/include/shared/net_kern.h
> +++ b/arch/um/include/shared/net_kern.h
> @@ -66,6 +66,6 @@ extern int tap_setup_common(char *str, char *type, char **dev_name,
>   extern void register_transport(struct transport *new);
>   extern unsigned short eth_protocol(struct sk_buff *skb);
>   extern void uml_net_setup_etheraddr(struct net_device *dev, char *str);
> -
> +extern int vector_compat_eth_configure(char *str, int index);
>   
>   #endif
> diff --git a/arch/um/include/shared/net_user.h b/arch/um/include/shared/net_user.h
> index 1b0531769a5e..b523e469256c 100644
> --- a/arch/um/include/shared/net_user.h
> +++ b/arch/um/include/shared/net_user.h
> @@ -50,4 +50,6 @@ extern char *split_if_spec(char *str, ...);
>   
>   extern int dev_netmask(void *d, void *m);
>   
> +extern void *uml_vector_compile_pcap(char *filter, int optimize);
> +
>   #endif
> 


We will need ot make PCAP depend on network io in config now. I forgot 
to do that. It will be added to the next revision.

Tap to follow up in the next couple of days - I need to unentangle all 
of the script invocations embedded around various files and see what 
they do. There is no need to change any of the actual network code - it 
is all already present.

MCAST should be fairly straight-forward - it just needs a socket open 
routine in vector_user.c. Everything else is in place.

DAEMON while less straight-forward is doable too.

That will leave VDE only on the old backend and unless someone actually 
comes out and says that they are still using it we can consider making 
that obsolete together with the old NET_UML backend.