Refactor ipv[46].[ch]

These are now combined into an inaddr.[ch], since their purpose is
to implement functions for struct in_addr and struct in6_addr.

The definitions for in6_addr and its allies are now in a separate
header, inaddr_st.h.

Closes ticket 26532.

1 files changed, 267 insertions, 0 deletions

diff --git a/src/lib/net/inaddr.c b/src/lib/net/inaddr.c
new file mode 100644
index 0000000000..dcd8fcdd65
--- /dev/null
+++ b/src/lib/net/inaddr.c
@@ -0,0 +1,267 @@
+/* Copyright (c) 2003-2004, Roger Dingledine
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file inaddr.c
+ * \brief Convert in_addr and in6_addr to and from strings.
+ **/
+
+#include "lib/net/inaddr.h"
+
+#include "lib/cc/torint.h"
+#include "lib/log/util_bug.h"
+#include "lib/net/inaddr_st.h"
+#include "lib/string/compat_ctype.h"
+#include "lib/string/compat_string.h"
+#include "lib/string/printf.h"
+#include "lib/string/scanf.h"
+#include "lib/string/util_string.h"
+
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef _WIN32
+#include <winsock2.h>
+#endif
+
+/** Set *addr to the IP address (in dotted-quad notation) stored in *str.
+ * Return 1 on success, 0 if *str is badly formatted.
+ * (Like inet_aton(str,addr), but works on Windows and Solaris.)
+ */
+int
+tor_inet_aton(const char *str, struct in_addr* addr)
+{
+  unsigned a,b,c,d;
+  char more;
+  if (tor_sscanf(str, "%3u.%3u.%3u.%3u%c", &a,&b,&c,&d,&more) != 4)
+    return 0;
+  if (a > 255) return 0;
+  if (b > 255) return 0;
+  if (c > 255) return 0;
+  if (d > 255) return 0;
+  addr->s_addr = htonl((a<<24) | (b<<16) | (c<<8) | d);
+  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>. Returns a non-negative integer on success.
+ *  Returns -1 on failure.
+ */
+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 <b>af</b>==AF_INET and <b>src</b> a struct in_addr, or
+ * <b>af</b>==AF_INET6 and <b>src</b> a struct in6_addr, try to format the
+ * address and store it in the <b>len</b>-byte buffer <b>dst</b>.  Returns
+ * <b>dst</b> on success, NULL on failure.
+ *
+ * (Like inet_ntop(af,src,dst,len), but works on platforms that don't have it:
+ * Tor sometimes needs to format ipv6 addresses even on platforms without ipv6
+ * support.) */
+const char *
+tor_inet_ntop(int af, const void *src, char *dst, size_t len)
+{
+  if (af == AF_INET) {
+    if (tor_inet_ntoa(src, dst, len) < 0)
+      return NULL;
+    else
+      return dst;
+  } else if (af == AF_INET6) {
+    const struct in6_addr *addr = src;
+    char buf[64], *cp;
+    int longestGapLen = 0, longestGapPos = -1, i,
+      curGapPos = -1, curGapLen = 0;
+    uint16_t words[8];
+    for (i = 0; i < 8; ++i) {
+      words[i] = (((uint16_t)addr->s6_addr[2*i])<<8) + addr->s6_addr[2*i+1];
+    }
+    if (words[0] == 0 && words[1] == 0 && words[2] == 0 && words[3] == 0 &&
+        words[4] == 0 && ((words[5] == 0 && words[6] && words[7]) ||
+                          (words[5] == 0xffff))) {
+      /* This is an IPv4 address. */
+      if (words[5] == 0) {
+        tor_snprintf(buf, sizeof(buf), "::%d.%d.%d.%d",
+                     addr->s6_addr[12], addr->s6_addr[13],
+                     addr->s6_addr[14], addr->s6_addr[15]);
+      } else {
+        tor_snprintf(buf, sizeof(buf), "::%x:%d.%d.%d.%d", words[5],
+                     addr->s6_addr[12], addr->s6_addr[13],
+                     addr->s6_addr[14], addr->s6_addr[15]);
+      }
+      if ((strlen(buf) + 1) > len) /* +1 for \0 */
+        return NULL;
+      strlcpy(dst, buf, len);
+      return dst;
+    }
+    i = 0;
+    while (i < 8) {
+      if (words[i] == 0) {
+        curGapPos = i++;
+        curGapLen = 1;
+        while (i<8 && words[i] == 0) {
+          ++i; ++curGapLen;
+        }
+        if (curGapLen > longestGapLen) {
+          longestGapPos = curGapPos;
+          longestGapLen = curGapLen;
+        }
+      } else {
+        ++i;
+      }
+    }
+    if (longestGapLen<=1)
+      longestGapPos = -1;
+
+    cp = buf;
+    for (i = 0; i < 8; ++i) {
+      if (words[i] == 0 && longestGapPos == i) {
+        if (i == 0)
+          *cp++ = ':';
+        *cp++ = ':';
+        while (i < 8 && words[i] == 0)
+          ++i;
+        --i; /* to compensate for loop increment. */
+      } else {
+        tor_snprintf(cp, sizeof(buf)-(cp-buf), "%x", (unsigned)words[i]);
+        cp += strlen(cp);
+        if (i != 7)
+          *cp++ = ':';
+      }
+    }
+    *cp = '\0';
+    if ((strlen(buf) + 1) > len) /* +1 for \0 */
+      return NULL;
+    strlcpy(dst, buf, len);
+    return dst;
+  } else {
+    return NULL;
+  }
+}
+
+/** Given <b>af</b>==AF_INET or <b>af</b>==AF_INET6, and a string <b>src</b>
+ * encoding an IPv4 address or IPv6 address correspondingly, try to parse the
+ * address and store the result in <b>dst</b> (which must have space for a
+ * struct in_addr or a struct in6_addr, as appropriate).  Return 1 on success,
+ * 0 on a bad parse, and -1 on a bad <b>af</b>.
+ *
+ * (Like inet_pton(af,src,dst) but works on platforms that don't have it: Tor
+ * sometimes needs to format ipv6 addresses even on platforms without ipv6
+ * support.) */
+int
+tor_inet_pton(int af, const char *src, void *dst)
+{
+  if (af == AF_INET) {
+    return tor_inet_aton(src, dst);
+  } else if (af == AF_INET6) {
+    struct in6_addr *out = dst;
+    uint16_t words[8];
+    int gapPos = -1, i, setWords=0;
+    const char *dot = strchr(src, '.');
+    const char *eow; /* end of words. */
+    memset(words, 0xf8, sizeof(words));
+    if (dot == src)
+      return 0;
+    else if (!dot)
+      eow = src+strlen(src);
+    else {
+      unsigned byte1,byte2,byte3,byte4;
+      char more;
+      for (eow = dot-1; eow > src && TOR_ISDIGIT(*eow); --eow)
+        ;
+      if (*eow != ':')
+        return 0;
+      ++eow;
+
+      /* We use "scanf" because some platform inet_aton()s are too lax
+       * about IPv4 addresses of the form "1.2.3" */
+      if (tor_sscanf(eow, "%3u.%3u.%3u.%3u%c",
+                     &byte1,&byte2,&byte3,&byte4,&more) != 4)
+        return 0;
+
+      if (byte1 > 255 || byte2 > 255 || byte3 > 255 || byte4 > 255)
+        return 0;
+
+      words[6] = (byte1<<8) | byte2;
+      words[7] = (byte3<<8) | byte4;
+      setWords += 2;
+    }
+
+    i = 0;
+    while (src < eow) {
+      if (i > 7)
+        return 0;
+      if (TOR_ISXDIGIT(*src)) {
+        char *next;
+        ssize_t len;
+        long r = strtol(src, &next, 16);
+        if (next == NULL || next == src) {
+          /* The 'next == src' error case can happen on versions of openbsd
+           * which treat "0xfoo" as an error, rather than as "0" followed by
+           * "xfoo". */
+          return 0;
+        }
+
+        len = *next == '\0' ? eow - src : next - src;
+        if (len > 4)
+          return 0;
+        if (len > 1 && !TOR_ISXDIGIT(src[1]))
+          return 0; /* 0x is not valid */
+
+        tor_assert(r >= 0);
+        tor_assert(r < 65536);
+        words[i++] = (uint16_t)r;
+        setWords++;
+        src = next;
+        if (*src != ':' && src != eow)
+          return 0;
+        ++src;
+      } else if (*src == ':' && i > 0 && gapPos == -1) {
+        gapPos = i;
+        ++src;
+      } else if (*src == ':' && i == 0 && src+1 < eow && src[1] == ':' &&
+                 gapPos == -1) {
+        gapPos = i;
+        src += 2;
+      } else {
+        return 0;
+      }
+    }
+
+    if (setWords > 8 ||
+        (setWords == 8 && gapPos != -1) ||
+        (setWords < 8 && gapPos == -1))
+      return 0;
+
+    if (gapPos >= 0) {
+      int nToMove = setWords - (dot ? 2 : 0) - gapPos;
+      int gapLen = 8 - setWords;
+      tor_assert(nToMove >= 0);
+      memmove(&words[gapPos+gapLen], &words[gapPos],
+              sizeof(uint16_t)*nToMove);
+      memset(&words[gapPos], 0, sizeof(uint16_t)*gapLen);
+    }
+    for (i = 0; i < 8; ++i) {
+      out->s6_addr[2*i  ] = words[i] >> 8;
+      out->s6_addr[2*i+1] = words[i] & 0xff;
+    }
+
+    return 1;
+  } else {
+    return -1;
+  }
+}