r17358@pc-10-8-1-079: nickm | 2008-07-25 16:41:03 +0200

 Split out the address manipulation functions from compat and util: they were about 21% of the total of those, and spread out too much.


svn:r16208

1 files changed, 1180 insertions, 0 deletions

diff --git a/src/common/address.c b/src/common/address.c
new file mode 100644
index 000000000..35ea683cd
--- /dev/null
+++ b/src/common/address.c
@@ -0,0 +1,1180 @@
+/* Copyright (c) 2003-2004, Roger Dingledine
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2008, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+/* $Id$ */
+const char address_c_id[] =
+  "$Id$";
+
+/**
+ * \file compat.c
+ * \brief Wrappers to make calls more portable.  This code defines
+ * functions such as tor_malloc, tor_snprintf, get/set various data types,
+ * renaming, setting socket options, switching user IDs.  It is basically
+ * where the non-portable items are conditionally included depending on
+ * the platform.
+ **/
+
+/* This is required on rh7 to make strptime not complain.
+ * We also need it to make memmem get defined (where available)
+ */
+#define _GNU_SOURCE
+
+#include "orconfig.h"
+#include "compat.h"
+#include "util.h"
+#include "address.h"
+#include "log.h"
+
+#ifdef MS_WINDOWS
+#include <process.h>
+#include <windows.h>
+#endif
+
+#ifdef HAVE_UNAME
+#include <sys/utsname.h>
+#endif
+#ifdef HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_SYS_FCNTL_H
+#include <sys/fcntl.h>
+#endif
+#ifdef HAVE_PWD_H
+#include <pwd.h>
+#endif
+#ifdef HAVE_GRP_H
+#include <grp.h>
+#endif
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+#ifdef HAVE_SYS_RESOURCE_H
+#include <sys/resource.h>
+#endif
+#ifdef HAVE_ERRNO_H
+#include <errno.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+#ifndef HAVE_GETTIMEOFDAY
+#ifdef HAVE_FTIME
+#include <sys/timeb.h>
+#endif
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_NETDB_H
+#include <netdb.h>
+#endif
+#ifdef HAVE_SYS_PARAM_H
+#include <sys/param.h> /* FreeBSD needs this to know what version it is */
+#endif
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#ifdef HAVE_PTHREAD_H
+#include <pthread.h>
+#endif
+#ifdef HAVE_SIGNAL_H
+#include <signal.h>
+#endif
+#ifdef HAVE_UTIME_H
+#include <utime.h>
+#endif
+#ifdef HAVE_SYS_UTIME_H
+#include <sys/utime.h>
+#endif
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
+#ifdef HAVE_SYS_SYSLIMITS_H
+#include <sys/syslimits.h>
+#endif
+
+/** DOCDOC */
+socklen_t
+tor_addr_to_sockaddr(const tor_addr_t *a,
+                     uint16_t port,
+                     struct sockaddr *sa_out)
+{
+  if (a->family == AF_INET) {
+    struct sockaddr_in *sin = (struct sockaddr_in *)sa_out;
+    sin->sin_family = AF_INET;
+    sin->sin_port = port;
+    sin->sin_addr.s_addr = a->addr.in_addr.s_addr;
+    return sizeof(struct sockaddr_in);
+  } else if (a->family == AF_INET6) {
+    struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa_out;
+    tor_assert(a->family == AF_INET6);
+    memset(sin6, 0, sizeof(struct sockaddr_in6));
+    sin6->sin6_family = AF_INET6;
+    sin6->sin6_port = port;
+    memcpy(&sin6->sin6_addr, &a->addr.in6_addr, sizeof(struct in6_addr));
+    return sizeof(struct sockaddr_in6);
+  } else {
+    return -1;
+  }
+}
+
+/** DOCDOC */
+void
+tor_addr_from_sockaddr(tor_addr_t *a, const struct sockaddr *sa)
+{
+  memset(&a, 0, sizeof(tor_addr_t));
+  if (sa->sa_family == AF_INET) {
+    struct sockaddr_in *sin = (struct sockaddr_in *) sa;
+    a->family = AF_INET;
+    a->addr.in_addr.s_addr = sin->sin_addr.s_addr;
+  } else if (sa->sa_family == AF_INET6) {
+    struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) sa;
+    a->family = AF_INET6;
+    memcpy(&a->addr.in6_addr, &sin6->sin6_addr, sizeof(struct in6_addr));
+  }
+}
+
+/** Similar behavior to Unix gethostbyname: resolve <b>name</b>, and set
+ * *<b>addr</b> to the proper IP address and family. The <b>family</b>
+ * argument (which must be AF_INET, AF_INET6, or AF_UNSPEC) declares a
+ * <i>preferred</i> family, though another one may be returned if only one
+ * family is implemented for this address.
+ *
+ * Return 0 on success, -1 on failure; 1 on transient failure.
+ */
+int
+tor_addr_lookup(const char *name, uint16_t family, tor_addr_t *addr)
+{
+  /* Perhaps eventually this should be replaced by a tor_getaddrinfo or
+   * something.
+   */
+  struct in_addr iaddr;
+  struct in6_addr iaddr6;
+  tor_assert(name);
+  tor_assert(addr);
+  tor_assert(family == AF_INET || family == AF_UNSPEC);
+  memset(addr, 0, sizeof(addr)); /* Clear the extraneous fields. */
+  if (!*name) {
+    /* Empty address is an error. */
+    return -1;
+  } else if (tor_inet_pton(AF_INET, name, &iaddr)) {
+    /* It's an IPv4 IP. */
+    addr->family = AF_INET;
+    memcpy(&addr->addr.in_addr, &iaddr, sizeof(struct in_addr));
+    return 0;
+  } else if (tor_inet_pton(AF_INET6, name, &iaddr6)) {
+    addr->family = AF_INET6;
+    memcpy(&addr->addr.in6_addr, &iaddr6, sizeof(struct in6_addr));
+    return 0;
+  } else {
+#ifdef HAVE_GETADDRINFO
+    int err;
+    struct addrinfo *res=NULL, *res_p;
+    struct addrinfo *best=NULL;
+    struct addrinfo hints;
+    int result = -1;
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_family = family;
+    hints.ai_socktype = SOCK_STREAM;
+    err = getaddrinfo(name, NULL, &hints, &res);
+    if (!err) {
+      best = NULL;
+      for (res_p = res; res_p; res_p = res_p->ai_next) {
+        if (family == AF_UNSPEC) {
+          if (res_p->ai_family == AF_INET) {
+            best = res_p;
+            break;
+          } else if (res_p->ai_family == AF_INET6 && !best) {
+            best = res_p;
+          }
+        } else if (family == res_p->ai_family) {
+          best = res_p;
+          break;
+        }
+      }
+      if (!best)
+        best = res;
+      if (best->ai_family == AF_INET) {
+        addr->family = AF_INET;
+        memcpy(&addr->addr.in_addr,
+               &((struct sockaddr_in*)best->ai_addr)->sin_addr,
+               sizeof(struct in_addr));
+        result = 0;
+      } else if (best->ai_family == AF_INET6) {
+        addr->family = AF_INET6;
+        memcpy(&addr->addr.in6_addr,
+               &((struct sockaddr_in6*)best->ai_addr)->sin6_addr,
+               sizeof(struct in6_addr));
+        result = 0;
+      }
+      freeaddrinfo(res);
+      return result;
+    }
+    return (err == EAI_AGAIN) ? 1 : -1;
+#else
+    struct hostent *ent;
+    int err;
+#ifdef HAVE_GETHOSTBYNAME_R_6_ARG
+    char buf[2048];
+    struct hostent hostent;
+    int r;
+    r = gethostbyname_r(name, &hostent, buf, sizeof(buf), &ent, &err);
+#elif defined(HAVE_GETHOSTBYNAME_R_5_ARG)
+    char buf[2048];
+    struct hostent hostent;
+    ent = gethostbyname_r(name, &hostent, buf, sizeof(buf), &err);
+#elif defined(HAVE_GETHOSTBYNAME_R_3_ARG)
+    struct hostent_data data;
+    struct hostent hent;
+    memset(&data, 0, sizeof(data));
+    err = gethostbyname_r(name, &hent, &data);
+    ent = err ? NULL : &hent;
+#else
+    ent = gethostbyname(name);
+#ifdef MS_WINDOWS
+    err = WSAGetLastError();
+#else
+    err = h_errno;
+#endif
+#endif /* endif HAVE_GETHOSTBYNAME_R_6_ARG. */
+    if (ent) {
+      addr->family = ent->h_addrtype;
+      if (ent->h_addrtype == AF_INET) {
+        memcpy(&addr->addr.in_addr, ent->h_addr, sizeof(struct in_addr));
+      } else if (ent->h_addrtype == AF_INET6) {
+        memcpy(&addr->addr.in6_addr, ent->h_addr, sizeof(struct in6_addr));
+      } else {
+        tor_assert(0); /* gethostbyname() returned a bizarre addrtype */
+      }
+      return 0;
+    }
+#ifdef MS_WINDOWS
+    return (err == WSATRY_AGAIN) ? 1 : -1;
+#else
+    return (err == TRY_AGAIN) ? 1 : -1;
+#endif
+#endif
+  }
+}
+
+/** Return true iff <b>ip</b> is an IP reserved to localhost or local networks
+ * in RFC1918 or RFC4193 or RFC4291. (fec0::/10, deprecated by RFC3879, is
+ * also treated as internal for now.)
+ */
+int
+tor_addr_is_internal(const tor_addr_t *addr, int for_listening)
+{
+  uint32_t iph4 = 0;
+  uint32_t iph6[4];
+  sa_family_t v_family;
+  v_family = tor_addr_family(addr);
+
+  if (v_family == AF_INET) {
+    iph4 = tor_addr_to_ipv4h(addr);
+  } else if (v_family == AF_INET6) {
+    if (tor_addr_is_v4(addr)) { /* v4-mapped */
+      v_family = AF_INET;
+      iph4 = ntohl(tor_addr_to_in6_addr32(addr)[3]);
+    }
+  }
+
+  if (v_family == AF_INET6) {
+    const uint32_t *a32 = tor_addr_to_in6_addr32(addr);
+    iph6[0] = ntohl(a32[0]);
+    iph6[1] = ntohl(a32[1]);
+    iph6[2] = ntohl(a32[2]);
+    iph6[3] = ntohl(a32[3]);
+    if (for_listening && !iph6[0] && !iph6[1] && !iph6[2] && !iph6[3]) /* :: */
+      return 0;
+
+    if (((iph6[0] & 0xfe000000) == 0xfc000000) || /* fc00/7  - RFC4193 */
+        ((iph6[0] & 0xffc00000) == 0xfe800000) || /* fe80/10 - RFC4291 */
+        ((iph6[0] & 0xffc00000) == 0xfec00000))   /* fec0/10 D- RFC3879 */
+      return 1;
+
+    if (!iph6[0] && !iph6[1] && !iph6[2] &&
+        ((iph6[3] & 0xfffffffe) == 0x00000000))  /* ::/127 */
+      return 1;
+
+    return 0;
+  } else if (v_family == AF_INET) {
+    if (for_listening && !iph4) /* special case for binding to 0.0.0.0 */
+      return 0;
+    if (((iph4 & 0xff000000) == 0x0a000000) || /*       10/8 */
+        ((iph4 & 0xff000000) == 0x00000000) || /*        0/8 */
+        ((iph4 & 0xff000000) == 0x7f000000) || /*      127/8 */
+        ((iph4 & 0xffff0000) == 0xa9fe0000) || /* 169.254/16 */
+        ((iph4 & 0xfff00000) == 0xac100000) || /*  172.16/12 */
+        ((iph4 & 0xffff0000) == 0xc0a80000))   /* 192.168/16 */
+      return 1;
+    return 0;
+  }
+
+  /* unknown address family... assume it's not safe for external use */
+  /* rather than tor_assert(0) */
+  log_warn(LD_BUG, "tor_addr_is_internal() called with a non-IP address.");
+  return 1;
+}
+
+/** Convert a tor_addr_t <b>addr</b> into a string, and store it in
+ *  <b>dest</b> of size <b>len</b>.  Returns a pointer to dest on success,
+ *  or NULL on failure.  If <b>decorate</b>, surround IPv6 addresses with
+ *  brackets.
+ */
+const char *
+tor_addr_to_str(char *dest, const tor_addr_t *addr, int len, int decorate)
+{
+  const char *ptr;
+  tor_assert(addr && dest);
+
+  switch (tor_addr_family(addr)) {
+    case AF_INET:
+      if (len<3)
+        return NULL;
+      if (decorate)
+        ptr = tor_inet_ntop(AF_INET, &addr->addr.in_addr, dest+1, len-2);
+      else
+        ptr = tor_inet_ntop(AF_INET, &addr->addr.in_addr, dest, len);
+      if (ptr && decorate) {
+        *dest = '[';
+        memcpy(dest+strlen(dest), "]", 2);
+      }
+      break;
+    case AF_INET6:
+      ptr = tor_inet_ntop(AF_INET6, &addr->addr.in6_addr, dest, len);
+      break;
+    default:
+      return NULL;
+  }
+  return ptr;
+}
+
+/** Parse a string <b>s</b> containing an IPv4/IPv6 address, and possibly
+ *  a mask and port or port range.  Store the parsed address in
+ *  <b>addr_out</b>, a mask (if any) in <b>mask_out</b>, and port(s) (if any)
+ *  in <b>port_min_out</b> and <b>port_max_out</b>.
+ *
+ * The syntax is:
+ *   Address OptMask OptPortRange
+ *   Address ::= IPv4Address / "[" IPv6Address "]" / "*"
+ *   OptMask ::= "/" Integer /
+ *   OptPortRange ::= ":*" / ":" Integer / ":" Integer "-" Integer /
+ *
+ *  - If mask, minport, or maxport are NULL, we do not want these
+ *    options to be set; treat them as an error if present.
+ *  - If the string has no mask, the mask is set to /32 (IPv4) or /128 (IPv6).
+ *  - If the string has one port, it is placed in both min and max port
+ *    variables.
+ *  - If the string has no port(s), port_(min|max)_out are set to 1 and 65535.
+ *
+ *  Return an address family on success, or -1 if an invalid address string is
+ *  provided.
+ */
+int
+tor_addr_parse_mask_ports(const char *s, tor_addr_t *addr_out,
+                          maskbits_t *maskbits_out,
+                          uint16_t *port_min_out, uint16_t *port_max_out)
+{
+  char *base = NULL, *address, *mask = NULL, *port = NULL, *rbracket = NULL;
+  char *endptr;
+  int any_flag=0, v4map=0;
+
+  tor_assert(s);
+  tor_assert(addr_out);
+
+  /* IP, [], /mask, ports */
+#define MAX_ADDRESS_LENGTH (TOR_ADDR_BUF_LEN+2+(1+INET_NTOA_BUF_LEN)+12+1)
+
+  if (strlen(s) > MAX_ADDRESS_LENGTH) {
+    log_warn(LD_GENERAL, "Impossibly long IP %s; rejecting", escaped(s));
+    goto err;
+  }
+  base = tor_strdup(s);
+
+  /* Break 'base' into separate strings. */
+  address = base;
+  if (*address == '[') {  /* Probably IPv6 */
+    address++;
+    rbracket = strchr(address, ']');
+    if (!rbracket) {
+      log_warn(LD_GENERAL,
+               "No closing IPv6 bracket in address pattern; rejecting.");
+      goto err;
+    }
+  }
+  mask = strchr((rbracket?rbracket:address),'/');
+  port = strchr((mask?mask:(rbracket?rbracket:address)), ':');
+  if (port)
+    *port++ = '\0';
+  if (mask)
+    *mask++ = '\0';
+  if (rbracket)
+    *rbracket = '\0';
+  if (port && mask)
+    tor_assert(port > mask);
+  if (mask && rbracket)
+    tor_assert(mask > rbracket);
+
+  /* Now "address" is the a.b.c.d|'*'|abcd::1 part...
+   *     "mask" is the Mask|Maskbits part...
+   * and "port" is the *|port|min-max part.
+   */
+
+  /* Process the address portion */
+  memset(addr_out, 0, sizeof(tor_addr_t));
+
+  if (!strcmp(address, "*")) {
+    addr_out->family = AF_INET; /* AF_UNSPEC ???? XXXX_IP6 */
+    any_flag = 1;
+  } else if (tor_inet_pton(AF_INET6, address, &addr_out->addr.in6_addr) > 0) {
+    addr_out->family = AF_INET6;
+  } else if (tor_inet_pton(AF_INET, address, &addr_out->addr.in_addr) > 0) {
+    addr_out->family = AF_INET;
+  } else {
+    log_warn(LD_GENERAL, "Malformed IP %s in address pattern; rejecting.",
+             escaped(address));
+    goto err;
+  }
+
+  v4map = tor_addr_is_v4(addr_out);
+
+/*
+#ifdef ALWAYS_V6_MAP
+  if (v_family == AF_INET) {
+    v_family = AF_INET6;
+    IN_ADDR6(addr_out).s6_addr32[3] = IN6_ADDRESS(addr_out).s_addr;
+    memset(&IN6_ADDRESS(addr_out), 0, 10);
+    IN_ADDR6(addr_out).s6_addr16[5] = 0xffff;
+  }
+#else
+  if (v_family == AF_INET6 && v4map) {
+    v_family = AF_INET;
+    IN4_ADDRESS((addr_out).s_addr = IN6_ADDRESS(addr_out).s6_addr32[3];
+  }
+#endif
+*/
+
+  /* Parse mask */
+  if (maskbits_out) {
+    int bits = 0;
+    struct in_addr v4mask;
+
+    if (mask) {  /* the caller (tried to) specify a mask */
+      bits = (int) strtol(mask, &endptr, 10);
+      if (!*endptr) {  /* strtol converted everything, so it was an integer */
+        if ((bits<0 || bits>128) ||
+            ((tor_addr_family(addr_out) == AF_INET) && bits > 32)) {
+          log_warn(LD_GENERAL,
+                   "Bad number of mask bits (%d) on address range; rejecting.",
+                   bits);
+          goto err;
+        }
+      } else {  /* mask might still be an address-style mask */
+        if (tor_inet_pton(AF_INET, mask, &v4mask) > 0) {
+          bits = addr_mask_get_bits(ntohl(v4mask.s_addr));
+          if (bits < 0) {
+            log_warn(LD_GENERAL,
+                     "IPv4-style mask %s is not a prefix address; rejecting.",
+                     escaped(mask));
+            goto err;
+          }
+        } else { /* Not IPv4; we don't do address-style IPv6 masks. */
+          log_warn(LD_GENERAL,
+                   "Malformed mask on address range %s; rejecting.",
+                   escaped(s));
+          goto err;
+        }
+      }
+      if (tor_addr_family(addr_out) == AF_INET6 && v4map) {
+        if (bits > 32 && bits < 96) { /* Crazy */
+          log_warn(LD_GENERAL,
+                   "Bad mask bits %i for V4-mapped V6 address; rejecting.",
+                   bits);
+          goto err;
+        }
+        /* XXXX_IP6 is this really what we want? */
+        bits = 96 + bits%32; /* map v4-mapped masks onto 96-128 bits */
+      }
+    } else { /* pick an appropriate mask, as none was given */
+      if (any_flag)
+        bits = 0;  /* This is okay whether it's V6 or V4 (FIX V4-mapped V6!) */
+      else if (tor_addr_family(addr_out) == AF_INET)
+        bits = 32;
+      else if (tor_addr_family(addr_out) == AF_INET6)
+        bits = 128;
+    }
+    *maskbits_out = (maskbits_t) bits;
+  } else {
+    if (mask) {
+      log_warn(LD_GENERAL,
+               "Unexpected mask in addrss %s; rejecting", escaped(s));
+      goto err;
+    }
+  }
+
+  /* Parse port(s) */
+  if (port_min_out) {
+    uint16_t port2;
+    if (!port_max_out) /* caller specified one port; fake the second one */
+      port_max_out = &port2;
+
+    if (parse_port_range(port, port_min_out, port_max_out) < 0) {
+      goto err;
+    } else if ((*port_min_out != *port_max_out) && port_max_out == &port2) {
+      log_warn(LD_GENERAL,
+               "Wanted one port from address range, but there are two.");
+
+      port_max_out = NULL;  /* caller specified one port, so set this back */
+      goto err;
+    }
+  } else {
+    if (port) {
+      log_warn(LD_GENERAL,
+               "Unexpected ports in addrss %s; rejecting", escaped(s));
+      goto err;
+    }
+  }
+
+  tor_free(base);
+  return tor_addr_family(addr_out);
+ err:
+  tor_free(base);
+  return -1;
+}
+
+/** Determine whether an address is IPv4, either native or ipv4-mapped ipv6.
+ * Note that this is about representation only, as any decent stack will
+ * reject ipv4-mapped addresses received on the wire (and won't use them
+ * on the wire either).
+ */
+int
+tor_addr_is_v4(const tor_addr_t *addr)
+{
+  tor_assert(addr);
+
+  if (tor_addr_family(addr) == AF_INET)
+    return 1;
+
+  if (tor_addr_family(addr) == AF_INET6) {
+    /* First two don't need to be ordered */
+    uint32_t *a32 = tor_addr_to_in6_addr32(addr);
+    if (a32[0] == 0 && a32[1] == 0 && ntohl(a32[2]) == 0x0000ffffu)
+      return 1;
+  }
+
+  return 0; /* Not IPv4 - unknown family or a full-blood IPv6 address */
+}
+
+/** Determine whether an address <b>addr</b> is null, either all zeroes or
+ *  belonging to family AF_UNSPEC.
+ */
+int
+tor_addr_is_null(const tor_addr_t *addr)
+{
+  tor_assert(addr);
+
+  switch (tor_addr_family(addr)) {
+    case AF_INET6: {
+      uint32_t *a32 = tor_addr_to_in6_addr32(addr);
+      return (a32[0] == 0) && (a32[1] == 0) && (a32[2] == 0) && (a32[3] == 0);
+    }
+    case AF_INET:
+      return (tor_addr_to_ipv4n(addr) == 0);
+    case AF_UNSPEC:
+      return 1;
+    default:
+      log_warn(LD_BUG, "Called with unknown address family %d",
+               (int)tor_addr_family(addr));
+      return 0;
+  }
+  //return 1;
+}
+
+/** Return true iff <b>addr</b> is a loopback address */
+int
+tor_addr_is_loopback(const tor_addr_t *addr)
+{
+  tor_assert(addr);
+  switch (tor_addr_family(addr)) {
+    case AF_INET6: {
+      /* ::1 */
+      uint32_t *a32 = tor_addr_to_in6_addr32(addr);
+      return (a32[0] == 0) && (a32[1] == 0) && (a32[2] == 0) && (a32[3] == 1);
+    }
+    case AF_INET:
+      /* 127.0.0.1 */
+      return (tor_addr_to_ipv4h(addr) & 0xff000000) == 0x7f000000;
+    case AF_UNSPEC:
+      return 0;
+    default:
+      tor_fragile_assert();
+      return 0;
+  }
+}
+
+/** Take a 32-bit host-order ipv4 address <b>v4addr</b> and store it in the
+ *  tor_addr *<b>dest</b>.
+ */
+/*  XXXX_IP6 Temporary, for use while 32-bit int addresses are still being
+ *  passed around. */
+void
+tor_addr_from_ipv4h(tor_addr_t *dest, uint32_t v4addr)
+{
+  tor_assert(dest);
+  memset(dest, 0, sizeof(dest));
+  dest->family = AF_INET;
+  dest->addr.in_addr.s_addr = htonl(v4addr);
+}
+
+/** Copy a tor_addr_t from <b>src</b> to <b>dest</b>.
+ */
+void
+tor_addr_copy(tor_addr_t *dest, const tor_addr_t *src)
+{
+  tor_assert(src && dest);
+  memcpy(dest, src, sizeof(tor_addr_t));
+}
+
+/** Given two addresses <b>addr1</b> and <b>addr2</b>, return 0 if the two
+ * addresses are equivalent under the mask mbits, less than 0 if addr1
+ * preceeds addr2, and greater than 0 otherwise.
+ *
+ * Different address families (IPv4 vs IPv6) are always considered unequal.
+ */
+int
+tor_addr_compare(const tor_addr_t *addr1, const tor_addr_t *addr2)
+{
+  return tor_addr_compare_masked(addr1, addr2, 128);
+}
+
+/** As tor_addr_compare(), but only looks at the first <b>mask</b> bits of
+ * the address.
+ *
+ * Reduce over-specific masks (>128 for ipv6, >32 for ipv4) to 128 or 32.
+ */
+int
+tor_addr_compare_masked(const tor_addr_t *addr1, const tor_addr_t *addr2,
+                        maskbits_t mbits)
+{
+  uint32_t ip4a=0, ip4b=0;
+  sa_family_t v_family[2];
+  int idx;
+  uint32_t masked_a, masked_b;
+
+  tor_assert(addr1 && addr2);
+
+  /* XXXX021 this code doesn't handle mask bits right it's using v4-mapped v6
+   * addresses.  If I ask whether ::ffff:1.2.3.4 and ::ffff:1.2.7.8 are the
+   * same in the first 16 bits, it will say "yes."  That's not so intuitive.
+   *
+   * XXXX021 Also, it's way too complicated.
+   */
+
+  v_family[0] = tor_addr_family(addr1);
+  v_family[1] = tor_addr_family(addr2);
+
+  if (v_family[0] == AF_UNSPEC) {
+    if (v_family[1] == AF_UNSPEC)
+      return 0;
+    else
+      return 1;
+  } else {
+    if (v_family[1] == AF_UNSPEC)
+      return -1;
+  }
+
+  if (v_family[0] == AF_INET) { /* If this is native IPv4, note the address */
+    /* Later we risk overwriting a v4-mapped address */
+    ip4a = tor_addr_to_ipv4h(addr1);
+  } else if ((v_family[0] == AF_INET6) && tor_addr_is_v4(addr1)) {
+    v_family[0] = AF_INET;
+    ip4a = tor_addr_to_mapped_ipv4h(addr1);
+  }
+
+  if (v_family[1] == AF_INET) { /* If this is native IPv4, note the address */
+    /* Later we risk overwriting a v4-mapped address */
+    ip4b = tor_addr_to_ipv4h(addr2);
+  } else if ((v_family[1] == AF_INET6) && tor_addr_is_v4(addr2)) {
+    v_family[1] = AF_INET;
+    ip4b = tor_addr_to_mapped_ipv4h(addr2);
+  }
+
+  if (v_family[0] > v_family[1]) /* Comparison of virtual families */
+    return 1;
+  else if (v_family[0] < v_family[1])
+    return -1;
+
+  if (mbits == 0)  /* Under a complete wildcard mask, consider them equal */
+    return 0;
+
+  if (v_family[0] == AF_INET) { /* Real or mapped IPv4 */
+    if (mbits >= 32) {
+      masked_a = ip4a;
+      masked_b = ip4b;
+    } else if (mbits == 0) {
+      return 0;
+    } else {
+      masked_a = ip4a >> (32-mbits);
+      masked_b = ip4b >> (32-mbits);
+    }
+    if (masked_a < masked_b)
+      return -1;
+    else if (masked_a > masked_b)
+      return 1;
+    return 0;
+  } else if (v_family[0] == AF_INET6) { /* Real IPv6 */
+    const uint32_t *a1 = tor_addr_to_in6_addr32(addr1);
+    const uint32_t *a2 = tor_addr_to_in6_addr32(addr2);
+    for (idx = 0; idx < 4; ++idx) {
+      uint32_t masked_a = ntohl(a1[idx]);
+      uint32_t masked_b = ntohl(a2[idx]);
+      if (!mbits) {
+        return 0; /* Mask covers both addresses from here on */
+      } else if (mbits < 32) {
+        masked_a >>= (32-mbits);
+        masked_b >>= (32-mbits);
+      }
+
+      if (masked_a > masked_b)
+        return 1;
+      else if (masked_a < masked_b)
+        return -1;
+
+      if (mbits < 32)
+        return 0;
+      mbits -= 32;
+    }
+    return 0;
+  }
+
+  tor_assert(0);  /* Unknown address family */
+  return -1; /* unknown address family, return unequal? */
+
+}
+
+
+/** Return a hash code based on the address addr */
+unsigned int
+tor_addr_hash(const tor_addr_t *addr)
+{
+  switch (tor_addr_family(addr)) {
+  case AF_INET:
+    return tor_addr_to_ipv4h(addr);
+  case AF_UNSPEC:
+    return 0x4e4d5342;
+  case AF_INET6: {
+    const uint32_t *u = tor_addr_to_in6_addr32(addr);
+    return u[0] + u[1] + u[2] + u[3];
+    }
+  default:
+    tor_fragile_assert();
+    return 0;
+  }
+}
+
+/** Return a newly allocatd string with a representation of <b>addr</b>. */
+char *
+tor_dup_addr(const tor_addr_t *addr)
+{
+  char buf[TOR_ADDR_BUF_LEN];
+  tor_addr_to_str(buf, addr, sizeof(buf), 0);
+  return tor_strdup(buf);
+}
+
+/** Convert the string in <b>src</b> to a tor_addr_t <b>addr</b>.
+ *
+ *  Return an address family on success, or -1 if an invalid address string is
+ *  provided. */
+int
+tor_addr_from_str(tor_addr_t *addr, const char *src)
+{
+  tor_assert(addr && src);
+  return tor_addr_parse_mask_ports(src, addr, NULL, NULL, NULL);
+}
+
+
+/** Set *<b>addr</b> to the IP address (if any) of whatever interface
+ * connects to the internet.  This address should only be used in checking
+ * whether our address has changed.  Return 0 on success, -1 on failure.
+ */
+int
+get_interface_address6(int severity, sa_family_t family, tor_addr_t *addr)
+{
+  int sock=-1, r=-1;
+  struct sockaddr_storage my_addr, target_addr;
+  socklen_t my_addr_len;
+
+  tor_assert(addr);
+
+  memset(addr, 0, sizeof(tor_addr_t));
+  memset(&target_addr, 0, sizeof(target_addr));
+  my_addr_len = (socklen_t)sizeof(my_addr);
+  /* Use the "discard" service port */
+  ((struct sockaddr_in*)&target_addr)->sin_port = 9;
+  /* Don't worry: no packets are sent. We just need to use a real address
+   * on the actual internet. */
+  if (family == AF_INET6) {
+    struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)&target_addr;
+    sock = tor_open_socket(PF_INET6,SOCK_DGRAM,IPPROTO_UDP);
+    my_addr_len = (socklen_t)sizeof(struct sockaddr_in6);
+    sin6->sin6_family = AF_INET6;
+    S6_ADDR16(sin6->sin6_addr)[0] = htons(0x2002); /* 2002:: */
+  } else if (family == AF_INET) {
+    struct sockaddr_in *sin = (struct sockaddr_in*)&target_addr;
+    sock = tor_open_socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP);
+    my_addr_len = (socklen_t)sizeof(struct sockaddr_in);
+    sin->sin_family = AF_INET;
+    sin->sin_addr.s_addr = htonl(0x12000001); /* 18.0.0.1 */
+  } else {
+    return -1;
+  }
+  if (sock < 0) {
+    int e = tor_socket_errno(-1);
+    log_fn(severity, LD_NET, "unable to create socket: %s",
+           tor_socket_strerror(e));
+    goto err;
+  }
+
+  if (connect(sock,(struct sockaddr *)&target_addr,
+              (socklen_t)sizeof(target_addr))<0) {
+    int e = tor_socket_errno(sock);
+    log_fn(severity, LD_NET, "connect() failed: %s", tor_socket_strerror(e));
+    goto err;
+  }
+
+  if (getsockname(sock,(struct sockaddr*)&my_addr, &my_addr_len)) {
+    int e = tor_socket_errno(sock);
+    log_fn(severity, LD_NET, "getsockname() to determine interface failed: %s",
+           tor_socket_strerror(e));
+    goto err;
+  }
+
+  memcpy(addr, &my_addr, sizeof(tor_addr_t));
+  r=0;
+ err:
+  if (sock >= 0)
+    tor_close_socket(sock);
+  return r;
+}
+
+/* ======
+ * IPv4 helpers
+ * XXXX021 IPv6 deprecate some of these.
+ */
+
+/** Return true iff <b>ip</b> (in host order) is an IP reserved to localhost,
+ * or reserved for local networks by RFC 1918.
+ */
+int
+is_internal_IP(uint32_t ip, int for_listening)
+{
+  tor_addr_t myaddr;
+  myaddr.family = AF_INET;
+  myaddr.addr.in_addr.s_addr = htonl(ip);
+
+  return tor_addr_is_internal(&myaddr, for_listening);
+}
+
+/** Parse a string of the form "host[:port]" from <b>addrport</b>.  If
+ * <b>address</b> is provided, set *<b>address</b> to a copy of the
+ * host portion of the string.  If <b>addr</b> is provided, try to
+ * resolve the host portion of the string and store it into
+ * *<b>addr</b> (in host byte order).  If <b>port_out</b> is provided,
+ * store the port number into *<b>port_out</b>, or 0 if no port is given.
+ * If <b>port_out</b> is NULL, then there must be no port number in
+ * <b>addrport</b>.
+ * Return 0 on success, -1 on failure.
+ */
+int
+parse_addr_port(int severity, const char *addrport, char **address,
+                uint32_t *addr, uint16_t *port_out)
+{
+  const char *colon;
+  char *_address = NULL;
+  int _port;
+  int ok = 1;
+
+  tor_assert(addrport);
+
+  colon = strchr(addrport, ':');
+  if (colon) {
+    _address = tor_strndup(addrport, colon-addrport);
+    _port = (int) tor_parse_long(colon+1,10,1,65535,NULL,NULL);
+    if (!_port) {
+      log_fn(severity, LD_GENERAL, "Port %s out of range", escaped(colon+1));
+      ok = 0;
+    }
+    if (!port_out) {
+      char *esc_addrport = esc_for_log(addrport);
+      log_fn(severity, LD_GENERAL,
+             "Port %s given on %s when not required",
+             escaped(colon+1), esc_addrport);
+      tor_free(esc_addrport);
+      ok = 0;
+    }
+  } else {
+    _address = tor_strdup(addrport);
+    _port = 0;
+  }
+
+  if (addr) {
+    /* There's an addr pointer, so we need to resolve the hostname. */
+    if (tor_lookup_hostname(_address,addr)) {
+      log_fn(severity, LD_NET, "Couldn't look up %s", escaped(_address));
+      ok = 0;
+      *addr = 0;
+    }
+  }
+
+  if (address && ok) {
+    *address = _address;
+  } else {
+    if (address)
+      *address = NULL;
+    tor_free(_address);
+  }
+  if (port_out)
+    *port_out = ok ? ((uint16_t) _port) : 0;
+
+  return ok ? 0 : -1;
+}
+
+/** If <b>mask</b> is an address mask for a bit-prefix, return the number of
+ * bits.  Otherwise, return -1. */
+int
+addr_mask_get_bits(uint32_t mask)
+{
+  int i;
+  if (mask == 0)
+    return 0;
+  if (mask == 0xFFFFFFFFu)
+    return 32;
+  for (i=0; i<=32; ++i) {
+    if (mask == (uint32_t) ~((1u<<(32-i))-1)) {
+      return i;
+    }
+  }
+  return -1;
+}
+
+/** Compare two addresses <b>a1</b> and <b>a2</b> for equality under a
+ *  etmask of <b>mbits</b> bits.  Return -1, 0, or 1.
+ *
+ * XXXX_IP6 Temporary function to allow masks as bitcounts everywhere.  This
+ * will be replaced with an IPv6-aware version as soon as 32-bit addresses are
+ * no longer passed around.
+ */
+int
+addr_mask_cmp_bits(uint32_t a1, uint32_t a2, maskbits_t bits)
+{
+  if (bits > 32)
+    bits = 32;
+  else if (bits == 0)
+    return 0;
+
+  a1 >>= (32-bits);
+  a2 >>= (32-bits);
+
+  if (a1 < a2)
+    return -1;
+  else if (a1 > a2)
+    return 1;
+  else
+    return 0;
+}
+
+/** Parse a string <b>s</b> in the format of (*|port(-maxport)?)?, setting the
+ * various *out pointers as appropriate.  Return 0 on success, -1 on failure.
+ */
+int
+parse_port_range(const char *port, uint16_t *port_min_out,
+                 uint16_t *port_max_out)
+{
+  int port_min, port_max, ok;
+  tor_assert(port_min_out);
+  tor_assert(port_max_out);
+
+  if (!port || *port == '\0' || strcmp(port, "*") == 0) {
+    port_min = 1;
+    port_max = 65535;
+  } else {
+    char *endptr = NULL;
+    port_min = (int)tor_parse_long(port, 10, 0, 65535, &ok, &endptr);
+    if (!ok) {
+      log_warn(LD_GENERAL,
+               "Malformed port %s on address range; rejecting.",
+               escaped(port));
+      return -1;
+    } else if (endptr && *endptr == '-') {
+      port = endptr+1;
+      endptr = NULL;
+      port_max = (int)tor_parse_long(port, 10, 1, 65536, &ok, &endptr);
+      if (!ok) {
+        log_warn(LD_GENERAL,
+                 "Malformed port %s on address range; rejecting.",
+                 escaped(port));
+        return -1;
+      }
+    } else {
+      port_max = port_min;
+    }
+    if (port_min > port_max) {
+      log_warn(LD_GENERAL, "Insane port range on address policy; rejecting.");
+      return -1;
+    }
+  }
+
+  if (port_min < 1)
+    port_min = 1;
+  if (port_max > 65535)
+    port_max = 65535;
+
+  *port_min_out = (uint16_t) port_min;
+  *port_max_out = (uint16_t) port_max;
+
+  return 0;
+}
+
+/** Parse a string <b>s</b> in the format of
+ * (IP(/mask|/mask-bits)?|*)(:(*|port(-maxport))?)?, setting the various
+ * *out pointers as appropriate.  Return 0 on success, -1 on failure.
+ */
+int
+parse_addr_and_port_range(const char *s, uint32_t *addr_out,
+                          maskbits_t *maskbits_out, uint16_t *port_min_out,
+                          uint16_t *port_max_out)
+{
+  char *address;
+  char *mask, *port, *endptr;
+  struct in_addr in;
+  int bits;
+
+  tor_assert(s);
+  tor_assert(addr_out);
+  tor_assert(maskbits_out);
+  tor_assert(port_min_out);
+  tor_assert(port_max_out);
+
+  address = tor_strdup(s);
+  /* Break 'address' into separate strings.
+   */
+  mask = strchr(address,'/');
+  port = strchr(mask?mask:address,':');
+  if (mask)
+    *mask++ = '\0';
+  if (port)
+    *port++ = '\0';
+  /* Now "address" is the IP|'*' part...
+   *     "mask" is the Mask|Maskbits part...
+   * and "port" is the *|port|min-max part.
+   */
+
+  if (strcmp(address,"*")==0) {
+    *addr_out = 0;
+  } else if (tor_inet_aton(address, &in) != 0) {
+    *addr_out = ntohl(in.s_addr);
+  } else {
+    log_warn(LD_GENERAL, "Malformed IP %s in address pattern; rejecting.",
+             escaped(address));
+    goto err;
+  }
+
+  if (!mask) {
+    if (strcmp(address,"*")==0)
+      *maskbits_out = 0;
+    else
+      *maskbits_out = 32;
+  } else {
+    endptr = NULL;
+    bits = (int) strtol(mask, &endptr, 10);
+    if (!*endptr) {
+      /* strtol handled the whole mask. */
+      if (bits < 0 || bits > 32) {
+        log_warn(LD_GENERAL,
+                 "Bad number of mask bits on address range; rejecting.");
+        goto err;
+      }
+      *maskbits_out = bits;
+    } else if (tor_inet_aton(mask, &in) != 0) {
+      bits = addr_mask_get_bits(ntohl(in.s_addr));
+      if (bits < 0) {
+        log_warn(LD_GENERAL,
+                 "Mask %s on address range isn't a prefix; dropping",
+                 escaped(mask));
+        goto err;
+      }
+      *maskbits_out = bits;
+    } else {
+      log_warn(LD_GENERAL,
+               "Malformed mask %s on address range; rejecting.",
+               escaped(mask));
+      goto err;
+    }
+  }
+
+  if (parse_port_range(port, port_min_out, port_max_out)<0)
+    goto err;
+
+  tor_free(address);
+  return 0;
+ err:
+  tor_free(address);
+  return -1;
+}
+
+/** Given an IPv4 in_addr struct *<b>in</b> (in network order, as usual),
+ *  write it as a string into the <b>buf_len</b>-byte buffer in
+ *  <b>buf</b>.
+ */
+int
+tor_inet_ntoa(const struct in_addr *in, char *buf, size_t buf_len)
+{
+  uint32_t a = ntohl(in->s_addr);
+  return tor_snprintf(buf, buf_len, "%d.%d.%d.%d",
+                      (int)(uint8_t)((a>>24)&0xff),
+                      (int)(uint8_t)((a>>16)&0xff),
+                      (int)(uint8_t)((a>>8 )&0xff),
+                      (int)(uint8_t)((a    )&0xff));
+}
+
+/** Given a host-order <b>addr</b>, call tor_inet_ntop() on it
+ *  and return a strdup of the resulting address.
+ */
+char *
+tor_dup_ip(uint32_t addr)
+{
+  char buf[TOR_ADDR_BUF_LEN];
+  struct in_addr in;
+
+  in.s_addr = htonl(addr);
+  tor_inet_ntop(AF_INET, &in, buf, sizeof(buf));
+  return tor_strdup(buf);
+}
+
+
+/**
+ * Set *<b>addr</b> to the host-order IPv4 address (if any) of whatever
+ * interface connects to the internet.  This address should only be used in
+ * checking whether our address has changed.  Return 0 on success, -1 on
+ * failure.
+ */
+int
+get_interface_address(int severity, uint32_t *addr)
+{
+  tor_addr_t local_addr;
+  int r;
+
+  r = get_interface_address6(severity, AF_INET, &local_addr);
+  if (r>=0)
+    *addr = tor_addr_to_ipv4h(&local_addr);
+  return r;
+}