[exim-cvs] Bug 1394: PPv2 header modifed

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A: exim-cvs
Assumpte: [exim-cvs] Bug 1394: PPv2 header modifed
Gitweb: http://git.exim.org/exim.git/commitdiff/367193425cbb5a77ee8ada9c5b2a203ca293d823
Commit:     367193425cbb5a77ee8ada9c5b2a203ca293d823
Parent:     fabe4dd996dd1e08707c4c33c498d86deaae6edd
Author:     Todd Lyons <tlyons@???>
AuthorDate: Mon May 12 16:15:07 2014 -0700
Committer:  Todd Lyons <tlyons@???>
CommitDate: Tue May 13 11:21:51 2014 -0700


    Bug 1394: PPv2 header modifed


    The HAProxy dev team adjusted the layout of the 16 byte header to allow
      it to be used for SSL connections.  Had to adjust PPv2 handling code
      and perl proxy emulation script.
    Added link to this HAProxy commit in the documentation.
---
 doc/doc-txt/experimental-spec.txt |    2 ++
 src/src/smtp_in.c                 |   34 ++++++++++++++++++++++++----------
 src/src/string.c                  |    2 +-
 src/util/proxy_protocol_client.pl |    6 +++---
 4 files changed, 30 insertions(+), 14 deletions(-)


diff --git a/doc/doc-txt/experimental-spec.txt b/doc/doc-txt/experimental-spec.txt
index 018bfdd..d8c26bf 100644
--- a/doc/doc-txt/experimental-spec.txt
+++ b/doc/doc-txt/experimental-spec.txt
@@ -1025,6 +1025,8 @@ Proxy Protocol Support
Exim now has Experimental "Proxy Protocol" support. It was built on
specifications from:
http://haproxy.1wt.eu/download/1.5/doc/proxy-protocol.txt
+Above URL revised May 2014 to change version 2 spec:
+http://git.1wt.eu/web?p=haproxy.git;a=commitdiff;h=afb768340c9d7e50d8e

 The purpose of this function is so that an application load balancer,
 such as HAProxy, can sit in front of several Exim servers and Exim
diff --git a/src/src/smtp_in.c b/src/src/smtp_in.c
index aad778e..b7e60bf 100644
--- a/src/src/smtp_in.c
+++ b/src/src/smtp_in.c
@@ -623,10 +623,9 @@ union {
   } v1;
   struct {
     uschar sig[12];
-    uschar ver;
-    uschar cmd;
-    uschar fam;
-    uschar len;
+    uint8_t ver_cmd;
+    uint8_t fam;
+    uint16_t len;
     union {
       struct { /* TCP/UDP over IPv4, len = 12 */
         uint32_t src_addr;
@@ -657,7 +656,7 @@ struct sockaddr_in6 tmpaddr6;


int get_ok = 0;
int size, ret, fd;
-const char v2sig[13] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A\x02";
+const char v2sig[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
uschar *iptype; /* To display debug info */
struct timeval tv;
socklen_t vslen = 0;
@@ -693,16 +692,32 @@ if (ret == -1)
}

 if (ret >= 16 &&
-    memcmp(&hdr.v2, v2sig, 13) == 0)
+    memcmp(&hdr.v2, v2sig, 12) == 0)
   {
+  uint8_t ver, cmd;
+
+  /* May 2014: haproxy combined the version and command into one byte to
+     allow two full bytes for the length field in order to proxy SSL
+     connections.  SSL Proxy is not supported in this version of Exim, but
+     must still seperate values here. */
+  ver = (hdr.v2.ver_cmd & 0xf0) >> 4;
+  cmd = (hdr.v2.ver_cmd & 0x0f);
+
+  if (ver != 0x02)
+    {
+    DEBUG(D_receive) debug_printf("Invalid Proxy Protocol version: %d\n", ver);
+    goto proxyfail;
+    }
   DEBUG(D_receive) debug_printf("Detected PROXYv2 header\n");
+  /* The v2 header will always be 16 bytes per the spec. */
   size = 16 + hdr.v2.len;
   if (ret < size)
     {
-    DEBUG(D_receive) debug_printf("Truncated or too large PROXYv2 header\n");
+    DEBUG(D_receive) debug_printf("Truncated or too large PROXYv2 header (%d/%d)\n",
+                                  ret, size);
     goto proxyfail;
     }
-  switch (hdr.v2.cmd)
+  switch (cmd)
     {
     case 0x01: /* PROXY command */
       switch (hdr.v2.fam)
@@ -772,8 +787,7 @@ if (ret >= 16 &&
       break;
     default:
       DEBUG(D_receive)
-        debug_printf("Unsupported PROXYv2 command: 0x%02x\n",
-                     hdr.v2.cmd);
+        debug_printf("Unsupported PROXYv2 command: 0x%x\n", cmd);
       goto proxyfail;
     }
   }
diff --git a/src/src/string.c b/src/src/string.c
index 9143902..0f657dc 100644
--- a/src/src/string.c
+++ b/src/src/string.c
@@ -304,7 +304,7 @@ if (nonprintcount == 0) return s;
 /* Get a new block of store guaranteed big enough to hold the
 expanded string. */


-ss = store_get(length + nonprintcount * 4 + 1);
+ss = store_get(length + nonprintcount * 3 + 1);

/* Copy everying, escaping non printers. */

diff --git a/src/util/proxy_protocol_client.pl b/src/util/proxy_protocol_client.pl
index 7cfc13d..feae3ca 100644
--- a/src/util/proxy_protocol_client.pl
+++ b/src/util/proxy_protocol_client.pl
@@ -82,10 +82,10 @@ sub generate_preamble {
   if (!$opts{version} || $opts{version} == 2) {
     @preamble = (
       "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A", # 12 byte v2 header
-      "\x02",                                             # declares v2
-      "\x01",                                             # connection is proxied
+      "\x21",                                             # top 4 bits declares v2
+                                                          # bottom 4 bits is command
       $opts{6} ? "\x21" : "\x11",                         # inet6/4 and TCP (stream)
-      $opts{6} ? "\x24" : "\x0b",                         # 36 bytes / 12 bytes
+      $opts{6} ? "\x00\x24" : "\x00\x0b",                 # 36 bytes / 12 bytes
       $source_ip,
       $dest_ip,
       $source_port,