add iothaddr

CMakeLists.txt

@@ -12,8 +12,8 @@ include(CheckSymbolExists)
 # set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D_FORTIFY_SOURCE=2 -O2 -pedantic -Wall -Wextra")
 set(SYSTEM_IOTH_PATH ${CMAKE_INSTALL_FULL_LIBDIR}/ioth)
 
-set(LIBS_REQUIRED fduserdata vdeplug)
-set(HEADERS_REQUIRED nlinline+.h fduserdata.h libvdeplug.h)
+set(LIBS_REQUIRED fduserdata vdeplug mhash)
+set(HEADERS_REQUIRED nlinline+.h fduserdata.h libvdeplug.h mhash.h)
 set(CMAKE_REQUIRED_QUIET TRUE)
 
 foreach(THISLIB IN LISTS LIBS_REQUIRED)
@@ -41,6 +41,13 @@ set_target_properties(ioth PROPERTIES VERSION ${PROJECT_VERSION}
 install(TARGETS ioth DESTINATION ${CMAKE_INSTALL_LIBDIR})
 install(FILES ioth.h DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 
+add_library(iothaddr SHARED iothaddr.c)
+target_link_libraries(iothaddr -lmhash)
+set_target_properties(iothaddr PROPERTIES VERSION ${PROJECT_VERSION}
+    SOVERSION ${PROJECT_VERSION_MAJOR})
+install(TARGETS iothaddr DESTINATION ${CMAKE_INSTALL_LIBDIR})
+install(FILES iothaddr.h DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+
 configure_file(config.h.in config.h)
 
 add_subdirectory(test)

ioth.h

@@ -1,5 +1,6 @@
 #ifndef LIBIOTH_H
 #define LIBIOTH_H
+#include <stdio.h>
 #include <sys/socket.h>
 #include <sys/ioctl.h>
 #include <sys/uio.h>
@@ -82,5 +83,32 @@ struct ioth_functions {
 	typeof(sendto) *sendto;
 	typeof(sendmsg) *sendmsg;
 };
-#endif
 
+/* ------------------ MAC address conversions --------------- */
+
+#define MAC_ADDRSTRLEN 18
+
+/* This  function converts a 6 byte MAC address family into a character string.
+	 The buffer dst must be at least MAC_ADDRSTRLEN bytes */
+static inline const char *ioth_ntomac(const void *src, char *dst, size_t size) {
+  const unsigned char *mac = src;
+  snprintf(dst, size, "%02x:%02x:%02x:%02x:%02x:%02x",
+      mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+  return dst;
+}
+
+/* This  function converts the character string src into a 6 byte MAC address.
+	 src points to a characteer string in the form "xx:xx:xx:xx:xx:xx" or
+	 "xx-xx-xx-xx-xx-xx" where xx is a sequence of two hexadecimal digits
+	 (not case sensitive) */
+static inline int ioth_macton(const char *src, void *dst) {
+  unsigned char *mac = dst;
+  if (sscanf(src, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
+      mac, mac + 1, mac + 2, mac + 3, mac + 4, mac + 5) != 6)
+    if (sscanf(src, "%hhx-%hhx-%hhx-%hhx-%hhx-%hhx",
+          mac, mac + 1, mac + 2, mac + 3, mac + 4, mac + 5) != 6)
+      return 0;
+  return 1;
+}
+
+#endif

iothaddr.c

@@ -0,0 +1,84 @@
+/*
+ *   iothaddr.c: utility library for ioth address management
+ *       hash (md5sum) based mac and ipv6 host address + eui64 conversion
+ *
+ *   Copyright 2021 Renzo Davoli - Virtual Square Team
+ *   University of Bologna - Italy
+ *
+ *   This library is free software; you can redistribute it and/or modify it
+ *   under the terms of the GNU Lesser General Public License as published by
+ *   the Free Software Foundation; either version 2.1 of the License, or (at
+ *   your option) any later version.
+ *
+ *   You should have received a copy of the GNU Lesser General Public License
+ *   along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <mhash.h>
+#include <netinet/in.h>
+#include <string.h>
+#include <time.h>
+#include <iothaddr.h>
+
+void iothaddr_hash(void *addr, const char *name, const char *passwd, uint32_t otiptime) {
+	struct in6_addr *addr6 = addr;
+	size_t namelen = strlen(name);
+	MHASH td;
+	char out[mhash_get_block_size(MHASH_MD5)];
+	int i;
+	memset(out, 0, mhash_get_block_size(MHASH_MD5));
+	if (name[namelen-1] == '.') namelen--;
+	td=mhash_init(MHASH_MD5);
+	mhash(td, name, namelen);
+	if (passwd != NULL)
+		mhash(td, passwd, strlen(passwd));
+	if (otiptime != 0) {
+		uint32_t otiptime_n = htonl(otiptime);
+		mhash(td, &otiptime_n, sizeof(otiptime_n));
+	}
+	mhash_deinit(td, out);
+	for (i=8; i<16; i++)
+		addr6->s6_addr[i] ^= out[i-8];
+	addr6->s6_addr[8] &= ~0x3;   // locally adm, unicast
+}
+
+void iothaddr_hashmac(void *mac, const char *name, const char *passwd) {
+	unsigned char *umac = mac;
+	size_t namelen = strlen(name);
+	MHASH td;
+	char out[mhash_get_block_size(MHASH_MD5)];
+	int i;
+	memset(out, 0, mhash_get_block_size(MHASH_MD5));
+	if (name[namelen-1] == '.') namelen--;
+	td=mhash_init(MHASH_MD5);
+	mhash(td, name, namelen);
+	if (passwd != NULL)
+		mhash(td, passwd, strlen(passwd));
+	mhash_deinit(td, out);
+	for (i=0; i<3; i++)
+		umac[i] = out[i];
+	for (i=3; i<6; i++)
+		umac[i] = out[i+2];
+	umac[0] |= 0x2; // locally adm
+	umac[0] &= ~0x1; // unicast
+}
+
+void iothaddr_eui64(void *addr, void *mac) {
+	struct in6_addr *addr6 = addr;
+	unsigned char *umac = mac;
+	int i;
+	for (i=0; i<3; i++)
+		addr6->s6_addr[i + 8] = umac[i];
+	addr6->s6_addr[11] = 0xff;
+	addr6->s6_addr[12] = 0xfe;
+	for (i=3; i<6; i++)
+		addr6->s6_addr[i + 10] ^= umac[i];
+	addr6->s6_addr[8] ^= 0x2;   // L bit has inverse meaning.
+}
+
+void iothaddr_hasheui64(void *addr, const char *name, const char *passwd) {
+	unsigned char mac[6];
+	iothaddr_hashmac(mac, name, passwd);
+	iothaddr_eui64(addr, mac);
+}

iothaddr.h

@@ -0,0 +1,54 @@
+#ifndef IOTHADDR_H
+#define IOTHADDR_H
+#include <stdint.h>
+#include <time.h>
+
+/* hash based IPv6 address:
+	 the rightmost 64 bits of the address are XORed with the first 64 bit of
+	 the md5sum of the concatenation of:
+	 * name
+	 * passwd, if passwd != NULL
+	 * the big-endian 4 byte representation of otiptime, if otiptime  != 0.
+	 bits 71 and 72 of addr are cleared (locally adm unicast address. */
+/* e.g. addr: 2000:760::/64, name = "test.v2.cs.unibo.it", passwd = NULL, otiptime = 0
+	 the md5sum of "test.v2.cs.unibo.it" is 69d62fac095a5a2ee4c2c79f211e57e3
+	 The resulting address is 2000:760::68d6:2fac:95a:5a2e */
+void iothaddr_hash(void *addr, const char *name, const char *passwd, uint32_t otiptime);
+
+/* One Time IP address (OTIP), computation of otiptime:
+	 ((seconds since the epoch) / otip_period) + otip_offset.
+	 otip_period is the address expiration period.
+	 otip_offset can be used on servers to anticipate the validity of addresses to tolerate
+	 negative drifts or clients' clocks. */
+static inline uint32_t iothaddr_otiptime(int otip_period, int otip_offset) {
+  return (uint32_t) ((time(NULL) + otip_offset) / otip_period);
+}
+
+/* hash based mac address
+	 Let H be the md5sum of the concatenation of:
+   * name
+   * passwd, if passwd != NULL.
+	 The mac address is set to:
+	 H'[0] : H[1] : H[2] : H[5] : H[6] : H[7]
+	 (the first byte has the 7th bit set and the 8th cleared: locally adm unicast address)
+	 e.g. name = "test.v2.cs.unibo.it", passwd = NULL
+	 the md5sum of "test.v2.cs.unibo.it" is 69d62fac095a5a2ee4c2c79f211e57e3
+	 the mac address is: 69:d6:2f:5a:5a:2e */
+/* Hash based defined MAC address can avoid delays due to old info in arp tables
+	 for process migration or restarting */
+void iothaddr_hashmac(void *mac, const char *name, const char *passwd);
+
+/* compute the EUI64 based IPv6 address from the mac address.
+	 the rightmost 64 bits of the address are XORed with the EUI64 extension
+	 of the 6 bytes mac address. */
+void iothaddr_eui64(void *addr, void *mac);
+
+/* compute the EUI64 based IPv6 address from the hash computed mac address.
+	 This function computes iothaddr_eui64 on the result of iothaddr_hashmac */
+/* e.g. addr: 2000:760::/64, name = "test.v2.cs.unibo.it", passwd = NULL
+	 the md5sum of "test.v2.cs.unibo.it" is 69d62fac095a5a2ee4c2c79f211e57e3
+   the mac address is: 69:d6:2f:5a:5a:2e
+	 The resulting address is 2000:760::68d6:2fff:fe5a:5a2e */
+void iothaddr_hasheui64(void *addr, const char *name, const char *passwd);
+
+#endif