BUG/MEDIUM: spoe: Flags are not encoded in network order

The flags are direct copy of the "unsigned int" in the network stream,
so the stream contains a 32 bits field encoded with the host endian.
 - This is not reliable for stream betwen different architecture host
 - For x86, the bits doesn't correspond to the documentation.

This patch add some precision in the documentation and put the bitfield
in the stream usig network butes order.

Warning: this patch can break compatibility with existing agents.

This patch should be backported in all version supporing SPOE

Original network capture:

   12:28:16.181343 IP 127.0.0.1.46782 > 127.0.0.1.12345: Flags [P.], seq 134:168, ack 59, win 342, options [nop,nop,TS val 2855241281 ecr 2855241281], length 34
           0x0000:  4500 0056 6b94 4000 4006 d10b 7f00 0001  E..Vk.@.@.......
           0x0010:  7f00 0001 b6be 3039 a3d1 ee54 7d61 d6f7  ......09...T}a..
           0x0020:  8018 0156 fe4a 0000 0101 080a aa2f 8641  ...V.J......./.A
           0x0030:  aa2f 8641 0000 001e 0301 0000 0000 010f  ./.A............
                                          ^^^^^^^^^^
           0x0040:  6368 6563 6b2d 636c 6965 6e74 2d69 7001  check-client-ip.
           0x0050:  0006 7f00 0001                           ......

Fixed network capture:

   12:24:26.948165 IP 127.0.0.1.46706 > 127.0.0.1.12345: Flags [P.], seq 4066280627:4066280661, ack 3148908096, win 342, options [nop,nop,TS val 2855183972 ecr 2855177690], length 34
           0x0000:  4500 0056 0538 4000 4006 3768 7f00 0001  E..V.8@.@.7h....
           0x0010:  7f00 0001 b672 3039 f25e 84b3 bbb0 8640  .....r09.^.....@
           0x0020:  8018 0156 fe4a 0000 0101 080a aa2e a664  ...V.J.........d
           0x0030:  aa2e 8dda 0000 001e 0300 0000 0114 010f  ................
                                          ^^^^^^^^^^
           0x0040:  6368 6563 6b2d 636c 6965 6e74 2d69 7001  check-client-ip.
           0x0050:  0006 7f00 0001                           ......

contrib/spoa_example/spoa.c

@@ -514,6 +514,7 @@ handle_hahello(struct spoe_frame *frame)
 
 	/* Retrieve flags */
 	memcpy((char *)&(frame->flags), p, 4);
+	frame->flags = ntohl(frame->flags);
 	p += 4;
 
 	/* Fragmentation is not supported for HELLO frame */
@@ -621,6 +622,7 @@ handle_hadiscon(struct spoe_frame *frame)
 
 	/* Retrieve flags */
 	memcpy((char *)&(frame->flags), p, 4);
+	frame->flags = ntohl(frame->flags);
 	p += 4;
 
 	/* Fragmentation is not supported for DISCONNECT frame */
@@ -702,6 +704,7 @@ handle_hanotify(struct spoe_frame *frame)
 
 	/* Retrieve flags */
 	memcpy((char *)&(frame->flags), p, 4);
+	frame->flags = ntohl(frame->flags);
 	p += 4;
 
 	/* Fragmentation is not supported */
@@ -764,6 +767,7 @@ handle_hafrag(struct spoe_frame *frame)
 
 	/* Retrieve flags */
 	memcpy((char *)&(frame->flags), p, 4);
+	frame->flags = ntohl(frame->flags);
 	p+= 4;
 
 	/* Read the stream-id and frame-id */
@@ -826,6 +830,7 @@ prepare_agenthello(struct spoe_frame *frame)
 	*p++ = SPOE_FRM_T_AGENT_HELLO;
 
 	/* Set flags */
+	flags = htonl(flags);
 	memcpy(p, (char *)&flags, 4);
 	p += 4;
 
@@ -907,6 +912,7 @@ prepare_agentdicon(struct spoe_frame *frame)
 	*p++ = SPOE_FRM_T_AGENT_DISCON;
 
 	/* Set flags */
+	flags = htonl(flags);
 	memcpy(p, (char *)&flags, 4);
 	p += 4;
 
@@ -954,6 +960,7 @@ prepare_agentack(struct spoe_frame *frame)
 	*p++ = SPOE_FRM_T_AGENT_ACK;
 
 	/* Set flags */
+	flags = htonl(flags);
 	memcpy(p, (char *)&flags, 4);
 	p += 4;
 

doc/SPOE.txt

@@ -694,7 +694,12 @@ actions.
     KV-NAME          : <STRING>
     KV-VALUE         : <TYPED-DATA>
 
-    FLAGS :   0   1      2-31
+    FLAGS :
+
+    Flags are a 32 bits field. They are encoded on 4 bytes in network byte
+    order, where the bit 0 is the LSB.
+
+              0   1      2-31
             +---+---+----------+
             |   | A |          |
             | F | B |          |

src/flt_spoe.c

@@ -399,6 +399,7 @@ spoe_prepare_hahello_frame(struct appctx *appctx, char *frame, size_t size)
 	*p++ = SPOE_FRM_T_HAPROXY_HELLO;
 
 	/* Set flags */
+	flags = htonl(flags);
 	memcpy(p, (char *)&flags, 4);
 	p += 4;
 
@@ -488,6 +489,7 @@ spoe_prepare_hadiscon_frame(struct appctx *appctx, char *frame, size_t size)
 	*p++ = SPOE_FRM_T_HAPROXY_DISCON;
 
 	/* Set flags */
+	flags = htonl(flags);
 	memcpy(p, (char *)&flags, 4);
 	p += 4;
 
@@ -559,6 +561,7 @@ spoe_prepare_hanotify_frame(struct appctx *appctx, struct spoe_context *ctx,
 	*p++ = SPOE_FRM_T_HAPROXY_NOTIFY;
 
 	/* Set flags */
+	flags = htonl(flags);
 	memcpy(p, (char *)&flags, 4);
 	p += 4;
 
@@ -615,6 +618,7 @@ spoe_prepare_hafrag_frame(struct appctx *appctx, struct spoe_context *ctx,
 	*p++ = SPOE_FRM_T_UNSET;
 
 	/* Set flags */
+	flags = htonl(flags);
 	memcpy(p, (char *)&flags, 4);
 	p += 4;
 
@@ -669,6 +673,7 @@ spoe_handle_agenthello_frame(struct appctx *appctx, char *frame, size_t size)
 
 	/* Retrieve flags */
 	memcpy((char *)&flags, p, 4);
+	flags = ntohl(flags);
 	p += 4;
 
 	/* Fragmentation is not supported for HELLO frame */
@@ -852,6 +857,7 @@ spoe_handle_agentdiscon_frame(struct appctx *appctx, char *frame, size_t size)
 
 	/* Retrieve flags */
 	memcpy((char *)&flags, p, 4);
+	flags = ntohl(flags);
 	p += 4;
 
 	/* Fragmentation is not supported for DISCONNECT frame */
@@ -962,6 +968,7 @@ spoe_handle_agentack_frame(struct appctx *appctx, struct spoe_context **ctx,
 
 	/* Retrieve flags */
 	memcpy((char *)&flags, p, 4);
+	flags = ntohl(flags);
 	p += 4;
 
 	/* Fragmentation is not supported for now */