net: introduce packet capture support

Add support for capturing ethernet packets and storing
them in memory in PCAP(2.4) format, later to be analyzed by
any PCAP viewer software (IE. Wireshark)

This feature greatly assist debugging network issues such
as detecting dropped packets, packet corruption etc.

Signed-off-by: Ramon Fried <rfried.dev@gmail.com>
Reviewed-by: Alex Marginean <alexm.osslist@gmail.com>
Tested-by: Alex Marginean <alexm.osslist@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

3 files changed, 79 insertions, 0 deletions

diff --git a/cmd/Kconfig b/cmd/Kconfig
index 05872fa0d7..98647f58b7 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1339,6 +1339,13 @@ config BOOTP_NTPSERVER
 	bool "Request & store 'ntpserverip' from BOOTP/DHCP server"
 	depends on CMD_BOOTP
 
+config CMD_PCAP
+	bool "pcap capture"
+	help
+	  Selecting this will allow capturing all Ethernet packets and store
+	  them in physical memory in a PCAP formated file,
+	  later to be analyzed by PCAP reader application (IE. WireShark).
+
 config BOOTP_PXE
 	bool "Send PXE client arch to BOOTP/DHCP server"
 	default y
diff --git a/cmd/Makefile b/cmd/Makefile
index 58827b5679..ac843b4b16 100644
--- a/cmd/Makefile
+++ b/cmd/Makefile
@@ -103,6 +103,7 @@ obj-$(CONFIG_CMD_NVEDIT_EFI) += nvedit_efi.o
 obj-$(CONFIG_CMD_ONENAND) += onenand.o
 obj-$(CONFIG_CMD_OSD) += osd.o
 obj-$(CONFIG_CMD_PART) += part.o
+obj-$(CONFIG_CMD_PCAP) += pcap.o
 ifdef CONFIG_PCI
 obj-$(CONFIG_CMD_PCI) += pci.o
 endif
diff --git a/cmd/pcap.c b/cmd/pcap.c
new file mode 100644
index 0000000000..980603f7bd
--- /dev/null
+++ b/cmd/pcap.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2019
+ * Ramon Fried <rfried.dev@gmail.com>
+ */
+
+#include <common.h>
+#include <command.h>
+#include <net.h>
+#include <net/pcap.h>
+
+static int do_pcap_init(cmd_tbl_t *cmdtp, int flag, int argc,
+			char * const argv[])
+{
+	phys_addr_t addr;
+	unsigned int size;
+
+	if (argc != 3)
+		return CMD_RET_USAGE;
+
+	addr = simple_strtoul(argv[1], NULL, 16);
+	size = simple_strtoul(argv[2], NULL, 10);
+
+	return pcap_init(addr, size) ? CMD_RET_FAILURE : CMD_RET_SUCCESS;
+}
+
+static int do_pcap_start(cmd_tbl_t *cmdtp, int flag, int argc,
+			 char * const argv[])
+{
+	return pcap_start_stop(true) ? CMD_RET_FAILURE : CMD_RET_SUCCESS;
+}
+
+static int do_pcap_stop(cmd_tbl_t *cmdtp, int flag, int argc,
+			char * const argv[])
+{
+	return pcap_start_stop(false) ? CMD_RET_FAILURE : CMD_RET_SUCCESS;
+}
+
+static int do_pcap_status(cmd_tbl_t *cmdtp, int flag, int argc,
+			  char * const argv[])
+{
+	return pcap_print_status() ? CMD_RET_FAILURE : CMD_RET_SUCCESS;
+}
+
+static int do_pcap_clear(cmd_tbl_t *cmdtp, int flag, int argc,
+			 char * const argv[])
+{
+	return pcap_clear() ? CMD_RET_FAILURE : CMD_RET_SUCCESS;
+}
+
+static char pcap_help_text[] =
+	"- network packet capture\n\n"
+	"pcap\n"
+	"pcap init\t\t\t<addr> <max_size>\n"
+	"pcap start\t\t\tstart capture\n"
+	"pcap stop\t\t\tstop capture\n"
+	"pcap status\t\t\tprint status\n"
+	"pcap clear\t\t\tclear capture buffer\n"
+	"\n"
+	"With:\n"
+	"\t<addr>: user address to which pcap will be stored (hexedcimal)\n"
+	"\t<max_size>: Maximum size of pcap file (decimal)\n"
+	"\n";
+
+U_BOOT_CMD_WITH_SUBCMDS(pcap, "pcap", pcap_help_text,
+			U_BOOT_SUBCMD_MKENT(init, 3, 0, do_pcap_init),
+			U_BOOT_SUBCMD_MKENT(start, 1, 0, do_pcap_start),
+			U_BOOT_SUBCMD_MKENT(stop, 1, 0, do_pcap_stop),
+			U_BOOT_SUBCMD_MKENT(status, 1, 0, do_pcap_status),
+			U_BOOT_SUBCMD_MKENT(clear, 1, 0, do_pcap_clear),
+);