MINOR: http_htx: add http_append_header() to append value to header
Calling this function as an alternative to http_replace_header_value()
to append a new value to existing header instead of replacing the whole
header content.
If the header already contains one or multiple values: a ',' is automatically
appended before the new value.
This function is not meant for prepending (providing empty ctx value),
in which case we should consider implementing dedicated prepend
alternative function.
diff --git a/include/haproxy/http_htx.h b/include/haproxy/http_htx.h
index 71f56bc..47f5336 100644
--- a/include/haproxy/http_htx.h
+++ b/include/haproxy/http_htx.h
@@ -50,6 +50,7 @@
int http_replace_req_query(struct htx *htx, const struct ist query);
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_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 58b2418..d4fdd07 100644
--- a/src/http_htx.c
+++ b/src/http_htx.c
@@ -537,6 +537,60 @@
return http_replace_stline(htx, vsn, status, reason);
}
+/* Append new value <data> after <ctx> value in header
+ * if header is not empty (at least one value exists):
+ * - ',' delimiter is added before <data> is appended
+ * - <ctx> must be valid and must point to an existing value,
+ * else it is an error and prepend_value should be used instead.
+ *
+ * ctx is updated to point to new value
+ *
+ * Returns 1 on success and 0 on failure.
+ */
+int http_append_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;
+
+ if (!blk)
+ goto fail;
+
+ v = htx_get_blk_value(htx, blk);
+
+ if (!istlen(v)) {
+ start = v.ptr;
+ goto empty; /* header is empty, append without ',' */
+ }
+ if (unlikely(!istlen(ctx->value)))
+ goto fail; /* invalid: value is empty, not supported */
+
+ start = istend(ctx->value) + ctx->lws_after;
+ off = start - v.ptr;
+
+ blk = htx_replace_blk_value(htx, blk, ist2(start, 0), ist(","));
+ if (!blk)
+ goto fail;
+ off += 1; /* add 1 for ',' */
+ v = htx_get_blk_value(htx, blk);
+ start = v.ptr + off;
+
+ empty:
+ blk = htx_replace_blk_value(htx, blk, ist2(start, 0), data);
+ if (!blk)
+ goto fail;
+ v = htx_get_blk_value(htx, blk);
+
+ 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.