Merge pull request #1 from unioslo/ether

Make the Ethernet address configurable.

include/ft/ethernet.h

@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2016-2017 The University of Oslo
+ * Copyright (c) 2016-2018 The University of Oslo
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -49,6 +49,7 @@ typedef struct ether_ftr {
 	uint32_t	 fcs;
 } __attribute__((__packed__)) ether_ftr;
 
-uint32_t ether_crc32(const uint8_t *, size_t);
+uint32_t	 ether_fcs(const uint8_t *, size_t);
+const char	*ether_parse(const char *, ether_addr *);
 
 #endif

lib/libft/ft_ether.c

@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2016 The University of Oslo
+ * Copyright (c) 2016-2018 The University of Oslo
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -30,6 +30,7 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include <ft/ctype.h>
 #include <ft/ethernet.h>
 
 static const uint32_t crc32tab[256] = {
@@ -99,8 +100,11 @@ static const uint32_t crc32tab[256] = {
 	0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d,
 };
 
+/*
+ * Compute the 32-bit Frame Check Sequence for an Ethernet frame.
+ */
 uint32_t
-ether_crc32(const uint8_t *data, size_t len)
+ether_fcs(const uint8_t *data, size_t len)
 {
 	uint32_t crc32;
 
@@ -109,3 +113,38 @@ ether_crc32(const uint8_t *data, size_t len)
 		crc32 = (crc32 >> 8) ^ crc32tab[(crc32 ^ *data++) & 0xff];
 	return (crc32);
 }
+
+/*
+ * Parse the textual representation of an Ethernet address.  We accept
+ * both the traditional colon-separated syntax and the less common
+ * hyphen-separated syntax.
+ */
+static const uint8_t x2b[256] = {
+	['0'] = 0x00, ['1'] = 0x01, ['2'] = 0x02, ['3'] = 0x03,
+	['4'] = 0x04, ['5'] = 0x05, ['6'] = 0x06, ['7'] = 0x07,
+	['8'] = 0x08, ['9'] = 0x09, ['A'] = 0x0a, ['B'] = 0x0b,
+	['C'] = 0x0c, ['D'] = 0x0d, ['E'] = 0x0e, ['F'] = 0x0f,
+	['a'] = 0x0a, ['b'] = 0x0b, ['c'] = 0x0c, ['d'] = 0x0d,
+	['e'] = 0x0e, ['f'] = 0x0f,
+};
+#define is_sep(ch) ((ch) == ':' || (ch) == '-')
+const char *
+ether_parse(const char *str, ether_addr *addr)
+{
+	const unsigned char *us;
+	char sep;
+	int i;
+
+	us = (const unsigned char *)str;
+	if (is_xdigit(us[0]) && is_xdigit(us[1]) && is_sep(us[2])) {
+		addr->o[0] = x2b[us[0]] << 4 | x2b[us[1]];
+		sep = us[2];
+		us += 2;
+		for (i = 1; i < 6; ++i, us += 3) {
+			if (us[0] != sep || !is_xdigit(us[1]) || !is_xdigit(us[2]))
+				return (NULL);
+			addr->o[i] = x2b[us[1]] << 4 | x2b[us[2]];
+		}
+	}
+	return ((const char *)us);
+}

sbin/flytrap/flytrap.8.in

@@ -26,7 +26,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd November 14, 2018
+.Dd November 21, 2018
 .Dt FLYTRAP 8
 .Os
 .Sh NAME
@@ -35,6 +35,7 @@
 .Sh SYNOPSIS
 .Nm
 .Op Fl dfnov
+.Op Fl e Ar addr
 .Op Fl I Ar addr Ns | Ns Ar range Ns | Ns Ar subnet
 .Op Fl i Ar addr Ns | Ns Ar range Ns | Ns Ar subnet
 .Op Fl p Ar pidfile
@@ -55,6 +56,8 @@ The following options are available:
 .Bl -tag -width Fl
 .It Fl d
 Enable log messages at debug level or higher.
+.It Fl e Ar addr
+Use the specified Ethernet address instead of the hardcoded default.
 .It Fl f
 Foreground mode: do not daemonize and do not create a pidfile.
 .It Fl I Ar a.b.c.d Ns | Ns Ar a.b.c.d-e.f.g.h Ns | Ns Ar a.b.c.d/p

sbin/flytrap/main.c

@@ -92,6 +92,20 @@ exclude_range(ip4s_node **set, const char *range)
 	return (0);
 }
 
+static int
+set_ether_addr(const char *addr)
+{
+	ether_addr ea;
+	const char *e;
+
+	if ((e = ether_parse(addr, &ea)) == NULL || *e != '\0')
+		return (-1);
+	ft_verbose("ethernet address %02x:%02x:%02x:%02x:%02x:%02x",
+	    ea.o[0], ea.o[1], ea.o[2], ea.o[3], ea.o[4], ea.o[5]);
+	flytrap_ether_addr = ea;
+	return (0);
+}
+
 static void
 daemonize(void)
 {
@@ -117,7 +131,7 @@ usage(void)
 {
 
 	fprintf(stderr, "usage: "
-	    "flytrap [-dfnov] [-p pidfile] [-t csvfile] "
+	    "flytrap [-dfnov] [-p pidfile] [-t csvfile] [-e addr] "
 	    "[-Ii addr|range|subnet] [-Xx addr|range|subnet] "
 	    "iface\n");
 	exit(1);
@@ -132,7 +146,7 @@ main(int argc, char *argv[])
 	ifname = NULL;
 	ft_log_level = FT_LOG_LEVEL_NOTICE;
 	ft_log_init("flytrap", NULL);
-	while ((opt = getopt(argc, argv, "dfhI:i:nop:t:vX:x:")) != -1) {
+	while ((opt = getopt(argc, argv, "de:fhI:i:nop:t:vX:x:")) != -1) {
 		switch (opt) {
 		case 'd':
 			if (ft_log_level > FT_LOG_LEVEL_DEBUG)
@@ -145,6 +159,10 @@ main(int argc, char *argv[])
 			if (include_range(&src_set, optarg) != 0)
 				usage();
 			break;
+		case 'e':
+			if (set_ether_addr(optarg) != 0)
+				usage();
+			break;
 		case 'i':
 			if (include_range(&dst_set, optarg) != 0)
 				usage();

t/.gitignore

@@ -1,5 +1,6 @@
 *.log
 *.trs
+/t_ether_addr
 /t_ip4_addr
 /t_ip4_range
 /t_ip4_set

t/Makefile.am

@@ -1,11 +1,14 @@
 AM_CPPFLAGS = -I$(top_srcdir)/include $(CRYB_TEST_CFLAGS)
 LIBFT = $(top_builddir)/lib/libft/libft.a
-noinst_HEADERS = t_ip4.h
+noinst_HEADERS = t_ether.h t_ip4.h
 
 if HAVE_CRYB_TEST
 
 check_PROGRAMS		 =
 
+check_PROGRAMS		+= t_ether_addr
+t_ether_addr_LDADD	 = $(LIBFT) $(CRYB_TEST_LIBS)
+
 check_PROGRAMS		+= t_ip4_addr
 t_ip4_addr_LDADD	 = $(LIBFT) $(CRYB_TEST_LIBS)
 

t/t_ether.h

@@ -0,0 +1,52 @@
+/*-
+ * Copyright (c) 2016-2018 The University of Oslo
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef T_ETHER_H_INCLUDED
+#define T_ETHER_H_INCLUDED
+
+#include <string.h>
+
+#include <ft/endian.h>
+#include <ft/ethernet.h>
+
+static inline int
+t_compare_ether_addr(const ether_addr *e, const ether_addr *r)
+{
+
+	if (memcmp(e, r, sizeof(ether_addr)) != 0) {
+		t_printv("expected %02x:%02x:%02x:%02x:%02x:%02x\n"
+		    "received %02x:%02x:%02x:%02x:%02x:%02x\n",
+		    e->o[0], e->o[1], e->o[2], e->o[3], e->o[4], e->o[5],
+		    r->o[0], r->o[1], r->o[2], r->o[3], r->o[4], r->o[5]);
+		return (0);
+	}
+	return (1);
+}
+
+#endif