Re: [dpdk-dev] [PATCH v4 3/3] net/pcap: build on Windows

[Tyler Retzlaff <roretzla@linux.microsoft.com>]

On Fri, Apr 16, 2021 at 01:10:55AM +0300, Dmitry Kozlyuk wrote:
> Implement OS-dependent functions and enable build for Windows.
> Account for different library name in Windows libpcap distributions.
> 
> Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>

Acked-by: Tyler Retzlaff <roretzla@linux.microsoft.com>

> ---
> Tyler, IIRC you were reviewing the code?
> This patch is the most important one but surprisingly has no acks.
> ---
>  config/meson.build                     |   5 +-
>  doc/guides/rel_notes/release_21_05.rst |   4 +
>  drivers/net/pcap/meson.build           |  11 ++-
>  drivers/net/pcap/pcap_ethdev.c         |   5 +-
>  drivers/net/pcap/pcap_osdep.h          |   5 ++
>  drivers/net/pcap/pcap_osdep_windows.c  | 118 +++++++++++++++++++++++++
>  6 files changed, 136 insertions(+), 12 deletions(-)
>  create mode 100644 drivers/net/pcap/pcap_osdep_windows.c
> 
> diff --git a/config/meson.build b/config/meson.build
> index 6e6ef8c0e1..6737cc3e26 100644
> --- a/config/meson.build
> +++ b/config/meson.build
> @@ -182,13 +182,14 @@ endif
>  
>  # check for pcap
>  pcap_dep = dependency('libpcap', required: false, method: 'pkg-config')
> +pcap_lib = is_windows ? 'wpcap' : 'pcap'
>  if not pcap_dep.found()
>  	# pcap got a pkg-config file only in 1.9.0
> -	pcap_dep = cc.find_library('pcap', required: false)
> +	pcap_dep = cc.find_library(pcap_lib, required: false)
>  endif
>  if pcap_dep.found() and cc.has_header('pcap.h', dependencies: pcap_dep)
>  	dpdk_conf.set('RTE_PORT_PCAP', 1)
> -	dpdk_extra_ldflags += '-lpcap'
> +	dpdk_extra_ldflags += '-l@0@'.format(pcap_lib)
>  endif
>  
>  # for clang 32-bit compiles we need libatomic for 64-bit atomic ops
> diff --git a/doc/guides/rel_notes/release_21_05.rst b/doc/guides/rel_notes/release_21_05.rst
> index 2e3bf5c95a..ed0e23a47b 100644
> --- a/doc/guides/rel_notes/release_21_05.rst
> +++ b/doc/guides/rel_notes/release_21_05.rst
> @@ -174,6 +174,10 @@ New Features
>    * Added command to display Rx queue used descriptor count.
>      ``show port (port_id) rxq (queue_id) desc used count``
>  
> +* **Enabled libpcap-based PMD on Windows.**
> +
> +   A libpcap distribution, such as Npcap or WinPcap, is required to run the PMD.
> +
>  
>  Removed Items
>  -------------
> diff --git a/drivers/net/pcap/meson.build b/drivers/net/pcap/meson.build
> index 26b6066990..63ad3f34f0 100644
> --- a/drivers/net/pcap/meson.build
> +++ b/drivers/net/pcap/meson.build
> @@ -1,18 +1,17 @@
>  # SPDX-License-Identifier: BSD-3-Clause
>  # Copyright(c) 2017 Intel Corporation
>  
> -if is_windows
> -	build = false
> -	reason = 'not supported on Windows'
> -	subdir_done()
> -endif
> -
>  if not dpdk_conf.has('RTE_PORT_PCAP')
>  	build = false
>  	reason = 'missing dependency, "libpcap"'
>  endif
> +
>  sources = files(
>  	'pcap_ethdev.c',
>  	'pcap_osdep_@0@.c'.format(exec_env),
>  )
> +
>  ext_deps += pcap_dep
> +if is_windows
> +	ext_deps += cc.find_library('iphlpapi', required: true)
> +endif
> diff --git a/drivers/net/pcap/pcap_ethdev.c b/drivers/net/pcap/pcap_ethdev.c
> index 4ac594eeca..3961843efc 100644
> --- a/drivers/net/pcap/pcap_ethdev.c
> +++ b/drivers/net/pcap/pcap_ethdev.c
> @@ -15,6 +15,7 @@
>  #include <rte_malloc.h>
>  #include <rte_mbuf.h>
>  #include <rte_bus_vdev.h>
> +#include <rte_os_shim.h>
>  
>  #include "pcap_osdep.h"
>  
> @@ -141,10 +142,6 @@ static struct rte_eth_link pmd_link = {
>  
>  RTE_LOG_REGISTER(eth_pcap_logtype, pmd.net.pcap, NOTICE);
>  
> -#define PMD_LOG(level, fmt, args...) \
> -	rte_log(RTE_LOG_ ## level, eth_pcap_logtype, \
> -		"%s(): " fmt "\n", __func__, ##args)
> -
>  static struct queue_missed_stat*
>  queue_missed_stat_update(struct rte_eth_dev *dev, unsigned int qid)
>  {
> diff --git a/drivers/net/pcap/pcap_osdep.h b/drivers/net/pcap/pcap_osdep.h
> index 9de422ab8d..bf41cba982 100644
> --- a/drivers/net/pcap/pcap_osdep.h
> +++ b/drivers/net/pcap/pcap_osdep.h
> @@ -7,6 +7,11 @@
>  
>  #include <rte_ether.h>
>  
> +#define PMD_LOG(level, fmt, args...) \
> +	rte_log(RTE_LOG_ ## level, eth_pcap_logtype, \
> +		"%s(): " fmt "\n", __func__, ##args)
> +extern int eth_pcap_logtype;
> +
>  int osdep_iface_index_get(const char *name);
>  int osdep_iface_mac_get(const char *name, struct rte_ether_addr *mac);
>  
> diff --git a/drivers/net/pcap/pcap_osdep_windows.c b/drivers/net/pcap/pcap_osdep_windows.c
> new file mode 100644
> index 0000000000..1d398dc7ed
> --- /dev/null
> +++ b/drivers/net/pcap/pcap_osdep_windows.c
> @@ -0,0 +1,118 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright (c) 2021 Dmitry Kozlyuk
> + */
> +
> +#include <winsock2.h>
> +#include <iphlpapi.h>
> +#include <strsafe.h>
> +
> +#include "pcap_osdep.h"
> +
> +/*
> + * Given a device name like "\Device\NPF_{GUID}" extract the "{GUID}" part.
> + * Return NULL if "{GUID}" part is not found.
> + */
> +static const char *
> +iface_guid(const char *name)
> +{
> +	static const size_t GUID_LENGTH = 32 + 4; /* 16 hex bytes + 4 dashes */
> +
> +	const char *ob, *cb;
> +
> +	ob = strchr(name, '{');
> +	if (ob == NULL)
> +		return NULL;
> +
> +	cb = strchr(ob, '}');
> +	if (cb == NULL || cb - ob != GUID_LENGTH + 1) /* + 1 opening '{' */
> +		return NULL;
> +
> +	return ob;
> +}
> +
> +/*
> + * libpcap takes device names like "\Device\NPF_{GUID}",
> + * GetAdapterIndex() takes interface names like "\DEVICE\TCPIP_{GUID}".
> + * Try to convert, fall back to original device name.
> + */
> +int
> +osdep_iface_index_get(const char *device_name)
> +{
> +	WCHAR adapter_name[MAX_ADAPTER_NAME_LENGTH];
> +	const char *guid;
> +	ULONG index;
> +	DWORD ret;
> +
> +	guid = iface_guid(device_name);
> +	if (guid != NULL)
> +		StringCbPrintfW(adapter_name, sizeof(adapter_name),
> +			L"\\DEVICE\\TCPIP_%S", guid);
> +	else
> +		StringCbPrintfW(adapter_name, sizeof(adapter_name),
> +			L"%S", device_name);
> +
> +	ret = GetAdapterIndex(adapter_name, &index);
> +	if (ret != NO_ERROR) {
> +		PMD_LOG(ERR, "GetAdapterIndex(%S) = %lu\n", adapter_name, ret);
> +		return -1;
> +	}
> +
> +	return index;
> +}
> +
> +/*
> + * libpcap takes device names like "\Device\NPF_{GUID}",
> + * GetAdaptersAddresses() returns names in "{GUID}" form.
> + * Try to extract GUID from device name, fall back to original device name.
> + */
> +int
> +osdep_iface_mac_get(const char *device_name, struct rte_ether_addr *mac)
> +{
> +	IP_ADAPTER_ADDRESSES *info = NULL, *cur = NULL;
> +	ULONG size, sys_ret;
> +	const char *adapter_name;
> +	int ret = -1;
> +
> +	sys_ret = GetAdaptersAddresses(AF_UNSPEC, 0, NULL, NULL, &size);
> +	if (sys_ret != ERROR_BUFFER_OVERFLOW) {
> +		PMD_LOG(ERR, "GetAdapterAddresses() = %lu, expected %lu\n",
> +			sys_ret, ERROR_BUFFER_OVERFLOW);
> +		return -1;
> +	}
> +
> +	info = (IP_ADAPTER_ADDRESSES *)malloc(size);
> +	if (info == NULL) {
> +		PMD_LOG(ERR, "Cannot allocate adapter address info\n");
> +		return -1;
> +	}
> +
> +	sys_ret = GetAdaptersAddresses(AF_UNSPEC, 0, NULL, info, &size);
> +	if (sys_ret != ERROR_SUCCESS) {
> +		PMD_LOG(ERR, "GetAdapterAddresses() = %lu\n", sys_ret);
> +		free(info);
> +		return -1;
> +	}
> +
> +	adapter_name = iface_guid(device_name);
> +	if (adapter_name == NULL)
> +		adapter_name = device_name;
> +
> +	for (cur = info; cur != NULL; cur = cur->Next) {
> +		if (strcmp(cur->AdapterName, adapter_name) == 0) {
> +			if (cur->PhysicalAddressLength != RTE_ETHER_ADDR_LEN) {
> +				PMD_LOG(ERR, "Physical address length: want %u, got %lu",
> +					RTE_ETHER_ADDR_LEN,
> +					cur->PhysicalAddressLength);
> +				break;
> +			}
> +
> +			memcpy(mac->addr_bytes, cur->PhysicalAddress,
> +				RTE_ETHER_ADDR_LEN);
> +			ret = 0;
> +			break;
> +		}
> +	}
> +
> +	free(info);
> +	return ret;
> +}
> -- 
> 2.29.3