From 35666ca5c6031b74605cee0a7ffb8d5359a8f46c Mon Sep 17 00:00:00 2001
From: Joshua Drake <zamnedix@sleepermud.net>
Date: Thu, 3 Dec 2015 13:52:51 -0800
Subject: [PATCH] Imported inet_pton from musl libc for Cygwin compilation

---
 p0f-client-exim.c | 89 ++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 72 insertions(+), 17 deletions(-)

diff --git a/p0f-client-exim.c b/p0f-client-exim.c
index 9d2711c..ea91e84 100644
--- a/p0f-client-exim.c
+++ b/p0f-client-exim.c
@@ -32,27 +32,83 @@
 #include "../debug.h"
 #include "../api.h"
 
-/* Parse IPv4 address into a buffer. */
-
-static void parse_addr4(char* str, u8* ret) {
-
-  u32 a1, a2, a3, a4;
-
-  if (sscanf(str, "%u.%u.%u.%u", &a1, &a2, &a3, &a4) != 4) {
-    SAYF("Malformed IPv4 address.");
-    exit(1);
+#ifdef CYGWIN
+
+#define AF_INET 0
+#define AF_INET6 1
+
+//From musl libc
+int inet_pton(int af, const char *restrict s, void *restrict a0)
+{
+  uint16_t ip[8];
+  unsigned char *a = a0;
+  int i, j, v, d, brk=-1, need_v4=0;
+
+  if (af==AF_INET) {
+    for (i=0; i<4; i++) {
+      for (v=j=0; j<3 && isdigit(s[j]); j++)
+        v = 10*v + s[j]-'0';
+      if (j==0 || (j>1 && s[0]=='0') || v>255) return 0;
+      a[i] = v;
+      if (s[j]==0 && i==3) return 1;
+      if (s[j]!='.') return 0;
+      s += j+1;
+    }
+    return 0;
+  } else if (af!=AF_INET6) {
+    errno = EAFNOSUPPORT;
+    return -1;
   }
 
-  if (a1 > 255 || a2 > 255 || a3 > 255 || a4 > 255) {
-    SAYF("Malformed IPv4 address.");
-    exit(1);
+  if (*s==':' && *++s!=':') return 0;
+
+  for (i=0; ; i++) {
+    if (s[0]==':' && brk<0) {
+      brk=i;
+      ip[i&7]=0;
+      if (!*++s) break;
+      if (i==7) return 0;
+      continue;
+    }
+    for (v=j=0; j<4 && (d=hexval(s[j]))>=0; j++)
+      v=16*v+d;
+    if (j==0) return 0;
+    ip[i&7] = v;
+    if (!s[j] && (brk>=0 || i==7)) break;
+    if (i==7) return 0;
+    if (s[j]!=':') {
+      if (s[j]!='.' || (i<6 && brk<0)) return 0;
+      need_v4=1;
+      i++;
+      break;
+    }
+    s += j+1;
+  }
+  if (brk>=0) {
+    memmove(ip+brk+7-i, ip+brk, 2*(i+1-brk));
+    for (j=0; j<7-i; j++) ip[brk+j] = 0;
+  }
+  for (j=0; j<8; j++) {
+    *a++ = ip[j]>>8;
+    *a++ = ip[j];
   }
+  if (need_v4 && inet_pton(AF_INET, (void *)s, a-4) <= 0) return 0;
+  return 1;
+}
+#endif
 
-  ret[0] = a1;
-  ret[1] = a2;
-  ret[2] = a3;
-  ret[3] = a4;
+/* Parse IPv4 address into a buffer. */
 
+static void parse_addr4(char* str, u8* ret) {
+  struct in_addr ip;
+  int8_t r = inet_pton(AF_INET6, str, &ip);
+  if    (r == -1) {
+    SAYF("parse_addr4: error while converting IPv6 address to binary format: %s", strerror(errno));
+  }
+  else if (r == 0) {
+    SAYF("parse_addr4: passed invalid IPv4 address");
+  }
+  memcpy(ret, &ip, 4);
 }
 
 
@@ -72,7 +128,6 @@ static void parse_addr6(char* str, u8* ret) {
   return;
 }
 
-
 int main(int argc, char** argv) {
 
   u8 tmp[128];
-- 
2.25.1