[RFC v1 1/2] um: drivers: remove support for UML_NET_PCAP

[Brendan Higgins]

Remove support for UML_NET_PCAP. It is broken. When building with
libpcap installed, the build fails:

arch/um/drivers/pcap_user.c:35:12: error: conflicting types for âpcap_openâ
 static int pcap_open(void *data)
            ^~~~~~~~~
In file included from /usr/include/pcap.h:43,
                 from arch/um/drivers/pcap_user.c:7:
/usr/include/pcap/pcap.h:859:18: note: previous declaration of âpcap_openâ was here
 PCAP_API pcap_t *pcap_open(const char *source, int snaplen, int flags,
                  ^~~~~~~~~

So it looks like this has probably been broken for some time.

In interest of trying to make allyesconfig work with UML, it is best
just to drop this.

Signed-off-by: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
---
 arch/um/drivers/Kconfig     |  16 -----
 arch/um/drivers/Makefile    |  17 +----
 arch/um/drivers/pcap_kern.c | 113 -----------------------------
 arch/um/drivers/pcap_user.c | 137 ------------------------------------
 arch/um/drivers/pcap_user.h |  21 ------
 5 files changed, 2 insertions(+), 302 deletions(-)
 delete mode 100644 arch/um/drivers/pcap_kern.c
 delete mode 100644 arch/um/drivers/pcap_user.c
 delete mode 100644 arch/um/drivers/pcap_user.h

diff --git a/arch/um/drivers/Kconfig b/arch/um/drivers/Kconfig
index 388096fb45a25..98fead07c33de 100644
--- a/arch/um/drivers/Kconfig
+++ b/arch/um/drivers/Kconfig
@@ -291,22 +291,6 @@ config UML_NET_MCAST
 	  exclusive).  If you don't need to network UMLs say N to each of
 	  the transports.
 
-config UML_NET_PCAP
-	bool "pcap transport"
-	depends on UML_NET
-	help
-	The pcap transport makes a pcap packet stream on the host look
-	like an ethernet device inside UML.  This is useful for making
-	UML act as a network monitor for the host.  You must have libcap
-	installed in order to build the pcap transport into UML.
-
-	  For more information, see
-	  <http://user-mode-linux.sourceforge.net/old/networking.html>  That site
-	  has examples of the UML command line to use to enable this option.
-
-	If you intend to use UML as a network monitor for the host, say
-	Y here.  Otherwise, say N.
-
 config UML_NET_SLIRP
 	bool "SLiRP transport"
 	depends on UML_NET
diff --git a/arch/um/drivers/Makefile b/arch/um/drivers/Makefile
index a290821e355c2..7548b18e77a27 100644
--- a/arch/um/drivers/Makefile
+++ b/arch/um/drivers/Makefile
@@ -3,9 +3,6 @@
 # Copyright (C) 2000, 2002, 2003 Jeff Dike (jdike@xxxxxxxxxx)
 #
 
-# pcap is broken in 2.5 because kbuild doesn't allow pcap.a to be linked
-# in to pcap.o
-
 slip-objs := slip_kern.o slip_user.o
 slirp-objs := slirp_kern.o slirp_user.o
 daemon-objs := daemon_kern.o daemon_user.o
@@ -18,14 +15,9 @@ ubd-objs := ubd_kern.o ubd_user.o
 port-objs := port_kern.o port_user.o
 harddog-objs := harddog_kern.o harddog_user.o
 
-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
-
-$(obj)/pcap.o: $(obj)/pcap_kern.o $(obj)/pcap_user.o
-	$(LD) -r -dp -o $@ $^ $(ld_flags)
+targets := vde_kern.o vde_user.o
 
 $(obj)/vde.o: $(obj)/vde_kern.o $(obj)/vde_user.o
 	$(LD) -r -dp -o $@ $^ $(ld_flags)
@@ -34,9 +26,6 @@ $(obj)/vde.o: $(obj)/vde_kern.o $(obj)/vde_user.o
 # object name, so nothing from the library gets linked.
 #$(call if_changed,ld)
 
-# When the above is fixed, don't forget to add this too!
-#targets += $(obj)/pcap.o
-
 obj-y := stdio_console.o fd.o chan_kern.o chan_user.o line.o
 obj-$(CONFIG_SSL) += ssl.o
 obj-$(CONFIG_STDERR_CONSOLE) += stderr_console.o
@@ -47,7 +36,6 @@ obj-$(CONFIG_UML_NET_DAEMON) += daemon.o
 obj-$(CONFIG_UML_NET_VECTOR) += vector.o
 obj-$(CONFIG_UML_NET_VDE) += vde.o
 obj-$(CONFIG_UML_NET_MCAST) += umcast.o
-obj-$(CONFIG_UML_NET_PCAP) += pcap.o
 obj-$(CONFIG_UML_NET) += net.o 
 obj-$(CONFIG_MCONSOLE) += mconsole.o
 obj-$(CONFIG_MMAPPER) += mmapper_kern.o 
@@ -63,8 +51,7 @@ obj-$(CONFIG_BLK_DEV_COW_COMMON) += cow_user.o
 obj-$(CONFIG_UML_RANDOM) += random.o
 obj-$(CONFIG_VIRTIO_UML) += virtio_uml.o
 
-# pcap_user.o must be added explicitly.
-USER_OBJS := fd.o null.o pty.o tty.o xterm.o slip_common.o pcap_user.o vde_user.o vector_user.o
+USER_OBJS := fd.o null.o pty.o tty.o xterm.o slip_common.o vde_user.o vector_user.o
 CFLAGS_null.o = -DDEV_NULL=$(DEV_NULL_PATH)
 
 include arch/um/scripts/Makefile.rules
diff --git a/arch/um/drivers/pcap_kern.c b/arch/um/drivers/pcap_kern.c
deleted file mode 100644
index cfe4cb17694cc..0000000000000
--- 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
deleted file mode 100644
index bbd20638788af..0000000000000
--- a/arch/um/drivers/pcap_user.c
+++ /dev/null
@@ -1,137 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- */
-
-#include <errno.h>
-#include <pcap.h>
-#include <string.h>
-#include <asm/types.h>
-#include <net_user.h>
-#include "pcap_user.h"
-#include <um_malloc.h>
-
-#define PCAP_FD(p) (*(int *)(p))
-
-static int pcap_user_init(void *data, void *dev)
-{
-	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;
-	}
-
-	pri->dev = dev;
-	pri->pcap = p;
-	return 0;
-}
-
-static int pcap_open(void *data)
-{
-	struct pcap_data *pri = data;
-	__u32 netmask;
-	int err;
-
-	if (pri->pcap == NULL)
-		return -ENODEV;
-
-	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;
-		}
-
-		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;
-		}
-	}
-
-	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;
-};
-
-static void handler(u_char *data, const struct pcap_pkthdr *header,
-		    const u_char *packet)
-{
-	int len;
-
-	struct pcap_handler_data *hdata = (struct pcap_handler_data *) data;
-
-	len = hdata->len < header->caplen ? hdata->len : header->caplen;
-	memcpy(hdata->buffer, packet, len);
-	hdata->len = len;
-}
-
-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 216246f5f09bd..0000000000000
--- 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@xxxxxxxxxx)
- */
-
-#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);
-
-- 
2.24.0.393.g34dc348eaf-goog