MINOR: http_htx: add http_prepend_header() to prepend value to header
Just like http_append_header(), but this time to insert new value before
an existing one.
If the header already contains one or multiple values, ',' is automatically
inserted after the new value.
diff --git a/include/haproxy/http_htx.h b/include/haproxy/http_htx.h
index 47f5336..3d01a06 100644
--- a/include/haproxy/http_htx.h
+++ b/include/haproxy/http_htx.h
@@ -51,6 +51,7 @@
int http_replace_res_status(struct htx *htx, const struct ist status, const struct ist reason);
int http_replace_res_reason(struct htx *htx, const struct ist reason);
int http_append_header_value(struct htx *htx, struct http_hdr_ctx *ctx, const struct ist data);
+int http_prepend_header_value(struct htx *htx, struct http_hdr_ctx *ctx, const struct ist data);
int http_replace_header_value(struct htx *htx, struct http_hdr_ctx *ctx, const struct ist data);
int http_replace_header(struct htx *htx, struct http_hdr_ctx *ctx, const struct ist name, const struct ist value);
int http_remove_header(struct htx *htx, struct http_hdr_ctx *ctx);
diff --git a/src/http_htx.c b/src/http_htx.c
index d4fdd07..c9d01aa 100644
--- a/src/http_htx.c
+++ b/src/http_htx.c
@@ -591,6 +591,63 @@
return 0;
}
+/* Prepend new value <data> before <ctx> value in header
+ * if <ctx> is not first value (at least one value exists):
+ * - ',' delimiter is added after <data> is prepended
+ *
+ * ctx is updated to point to new value
+ *
+ * Returns 1 on success and 0 on failure.
+ */
+int http_prepend_header_value(struct htx *htx, struct http_hdr_ctx *ctx, const struct ist data)
+{
+ char *start;
+ struct htx_blk *blk = ctx->blk;
+ struct ist v;
+ uint32_t off = 0;
+ uint8_t first = 0;
+
+ if (!blk)
+ goto fail;
+
+ v = htx_get_blk_value(htx, blk);
+
+ if (!istlen(v)) {
+ start = v.ptr;
+ first = 1;
+ }
+ if (unlikely(!istlen(ctx->value)))
+ goto fail; /* invalid: value is empty, not supported */
+
+ if (!first)
+ start = istptr(ctx->value) - ctx->lws_before;
+ off = start - v.ptr;
+
+ blk = htx_replace_blk_value(htx, blk, ist2(start, 0), data);
+ if (!blk)
+ goto fail;
+ v = htx_get_blk_value(htx, blk);
+
+ if (first)
+ goto end; /* header is empty, don't append ',' */
+
+ start = v.ptr + off + data.len;
+
+ blk = htx_replace_blk_value(htx, blk, ist2(start, 0), ist(","));
+ if (!blk)
+ goto fail;
+ v = htx_get_blk_value(htx, blk);
+
+ end:
+ ctx->blk = blk;
+ ctx->value = ist2(v.ptr + off, data.len);
+ ctx->lws_before = ctx->lws_after = 0;
+
+ return 1;
+ fail:
+ return 0;
+}
+
/* Replaces a part of a header value referenced in the context <ctx> by
* <data>. It returns 1 on success, otherwise it returns 0. The context is
* updated if necessary.