BUG/MEDIUM: samples: Fix handling of SMP_T_METH samples

Samples of type SMP_T_METH were not properly handled in smp_dup(),
smp_is_safe() and smp_is_rw(). For "other" methods, for instance PATCH, a
fallback was performed on the SMP_T_STR type. Only the buffer considered
changed. "smp->data.u.meth.str" should be used for the SMP_T_METH samples
while smp->data.u.str should be used for SMP_T_STR samples. However, in
smp_dup(), the result was stored in wrong buffer, the string one instead of
the method one. In smp_is_safe() and smp_is_rw(), the method buffer was not
used at all.

We now take care to use the right buffer.

This patch must be backported to all stable versions.

Author: capflam

include/haproxy/sample.h

@@ -101,23 +101,26 @@ struct sample *smp_set_owner(struct sample *smp, struct proxy *px,
 static inline
 int smp_is_safe(struct sample *smp)
 {
+	struct buffer *buf;
+
 	switch (smp->data.type) {
 	case SMP_T_METH:
 		if (smp->data.u.meth.meth != HTTP_METH_OTHER)
 			return 1;
 		__fallthrough;
 
 	case SMP_T_STR:
-		if (!smp->data.u.str.size || smp->data.u.str.data >= smp->data.u.str.size)
+		buf = (smp->data.type == SMP_T_STR ? &smp->data.u.str : &smp->data.u.meth.str);
+		if (!buf->size || buf->data >= buf->size)
 			return 0;
 
-		if (smp->data.u.str.area[smp->data.u.str.data] == 0)
+		if (buf->area[buf->data] == 0)
 			return 1;
 
 		if (smp->flags & SMP_F_CONST)
 			return 0;
 
-		smp->data.u.str.area[smp->data.u.str.data] = 0;
+		buf->area[buf->data] = 0;
 		return 1;
 
 	case SMP_T_BIN:
@@ -148,6 +151,8 @@ int smp_make_safe(struct sample *smp)
 static inline
 int smp_is_rw(struct sample *smp)
 {
+	struct buffer *buf;
+
 	if (smp->flags & SMP_F_CONST)
 		return 0;
 
@@ -158,12 +163,12 @@ int smp_is_rw(struct sample *smp)
 		__fallthrough;
 
 	case SMP_T_STR:
-		if (!smp->data.u.str.size ||
-		    smp->data.u.str.data >= smp->data.u.str.size)
+		buf = (smp->data.type == SMP_T_STR ? &smp->data.u.str : &smp->data.u.meth.str);
+		if (!buf->size || buf->data >= buf->size)
 			return 0;
 
-		if (smp->data.u.str.area[smp->data.u.str.data] != 0)
-			smp->data.u.str.area[smp->data.u.str.data] = 0;
+		if (buf->area[buf->data] != 0)
+			buf->area[buf->data] = 0;
 		return 1;
 
 	case SMP_T_BIN:

src/sample.c

@@ -885,7 +885,7 @@ static int c_int2str(struct sample *smp)
  */
 int smp_dup(struct sample *smp)
 {
-	struct buffer *trash;
+	struct buffer *trash, *buf;
 
 	switch (smp->data.type) {
 	case SMP_T_BOOL:
@@ -902,19 +902,17 @@ int smp_dup(struct sample *smp)
 		__fallthrough;
 
 	case SMP_T_STR:
-		trash = get_trash_chunk_sz(smp->data.u.str.data+1);
+		buf = (smp->data.type == SMP_T_STR ? &smp->data.u.str : &smp->data.u.meth.str);
+		trash = get_trash_chunk_sz(buf->data+1);
 		if (!trash)
 			return 0;
-		trash->data = smp->data.type == SMP_T_STR ?
-		    smp->data.u.str.data : smp->data.u.meth.str.data;
+		trash->data = buf->data;
 		if (trash->data > trash->size - 1)
 			trash->data = trash->size - 1;
 
-		memcpy(trash->area, smp->data.type == SMP_T_STR ?
-		    smp->data.u.str.area : smp->data.u.meth.str.area,
-		    trash->data);
+		memcpy(trash->area, buf->area, trash->data);
 		trash->area[trash->data] = 0;
-		smp->data.u.str = *trash;
+		*buf = *trash;
 		break;
 
 	case SMP_T_BIN: