MINOR: proto_htx: Add functions to apply req* and rsp* rules on HTX messages
It is more or less the same than legacy versions but adapted to be called from
HTX analyzers.
diff --git a/src/proto_htx.c b/src/proto_htx.c
index 2b2fcf6..c0f9d07 100644
--- a/src/proto_htx.c
+++ b/src/proto_htx.c
@@ -49,6 +49,9 @@
static enum rule_result htx_req_get_intercept_rule(struct proxy *px, struct list *rules, struct stream *s, int *deny_status);
static enum rule_result htx_res_get_intercept_rule(struct proxy *px, struct list *rules, struct stream *s);
+static int htx_apply_filters_to_request(struct stream *s, struct channel *req, struct proxy *px);
+static int htx_apply_filters_to_response(struct stream *s, struct channel *res, struct proxy *px);
+
/* This stream analyser waits for a complete HTTP request. It returns 1 if the
* processing can continue on next analysers, or zero if it either needs more
* data or wants to immediately abort the request (eg: timeout, error, ...). It
@@ -3454,6 +3457,431 @@
return rule_ret;
}
+/* Iterate the same filter through all request headers.
+ * Returns 1 if this filter can be stopped upon return, otherwise 0.
+ * Since it can manage the switch to another backend, it updates the per-proxy
+ * DENY stats.
+ */
+static int htx_apply_filter_to_req_headers(struct stream *s, struct channel *req, struct hdr_exp *exp)
+{
+ struct http_txn *txn = s->txn;
+ struct htx *htx;
+ struct buffer *hdr = get_trash_chunk();
+ int32_t pos;
+
+ htx = htx_from_buf(&req->buf);
+
+ for (pos = htx_get_head(htx); pos != -1; pos = htx_get_next(htx, pos)) {
+ struct htx_blk *blk = htx_get_blk(htx, pos);
+ enum htx_blk_type type;
+ struct ist n, v;
+
+ next_hdr:
+ type = htx_get_blk_type(blk);
+ if (type == HTX_BLK_EOH)
+ break;
+ if (type != HTX_BLK_HDR)
+ continue;
+
+ if (unlikely(txn->flags & (TX_CLDENY | TX_CLTARPIT)))
+ return 1;
+ else if (unlikely(txn->flags & TX_CLALLOW) &&
+ (exp->action == ACT_ALLOW ||
+ exp->action == ACT_DENY ||
+ exp->action == ACT_TARPIT))
+ return 0;
+
+ n = htx_get_blk_name(htx, blk);
+ v = htx_get_blk_value(htx, blk);
+
+ chunk_memcat(hdr, n.ptr, n.len);
+ hdr->area[hdr->data++] = ':';
+ hdr->area[hdr->data++] = ' ';
+ chunk_memcat(hdr, v.ptr, v.len);
+
+ /* Now we have one header in <hdr> */
+
+ if (regex_exec_match2(exp->preg, hdr->area, hdr->data, MAX_MATCH, pmatch, 0)) {
+ struct http_hdr_ctx ctx;
+ int len;
+
+ switch (exp->action) {
+ case ACT_ALLOW:
+ txn->flags |= TX_CLALLOW;
+ goto end;
+
+ case ACT_DENY:
+ txn->flags |= TX_CLDENY;
+ goto end;
+
+ case ACT_TARPIT:
+ txn->flags |= TX_CLTARPIT;
+ goto end;
+
+ case ACT_REPLACE:
+ len = exp_replace(trash.area, trash.size, hdr->area, exp->replace, pmatch);
+ if (len < 0)
+ return -1;
+
+ http_parse_header(ist2(trash.area, len), &n, &v);
+ ctx.blk = blk;
+ ctx.value = v;
+ if (!http_replace_header(htx, &ctx, n, v))
+ return -1;
+ if (!ctx.blk)
+ goto end;
+ pos = htx_get_blk_pos(htx, blk);
+ break;
+
+ case ACT_REMOVE:
+ ctx.blk = blk;
+ ctx.value = v;
+ if (!http_remove_header(htx, &ctx))
+ return -1;
+ if (!ctx.blk)
+ goto end;
+ pos = htx_get_blk_pos(htx, blk);
+ goto next_hdr;
+
+ }
+ }
+ }
+ end:
+ return 0;
+}
+
+/* Apply the filter to the request line.
+ * Returns 0 if nothing has been done, 1 if the filter has been applied,
+ * or -1 if a replacement resulted in an invalid request line.
+ * Since it can manage the switch to another backend, it updates the per-proxy
+ * DENY stats.
+ */
+static int htx_apply_filter_to_req_line(struct stream *s, struct channel *req, struct hdr_exp *exp)
+{
+ struct http_txn *txn = s->txn;
+ struct htx *htx;
+ struct buffer *reqline = get_trash_chunk();
+ int done;
+
+ htx = htx_from_buf(&req->buf);
+
+ if (unlikely(txn->flags & (TX_CLDENY | TX_CLTARPIT)))
+ return 1;
+ else if (unlikely(txn->flags & TX_CLALLOW) &&
+ (exp->action == ACT_ALLOW ||
+ exp->action == ACT_DENY ||
+ exp->action == ACT_TARPIT))
+ return 0;
+ else if (exp->action == ACT_REMOVE)
+ return 0;
+
+ done = 0;
+
+ reqline->data = htx_fmt_req_line(http_find_stline(htx), reqline->area, reqline->size);
+
+ /* Now we have the request line between cur_ptr and cur_end */
+ if (regex_exec_match2(exp->preg, reqline->area, reqline->data, MAX_MATCH, pmatch, 0)) {
+ union h1_sl sl;
+ int len;
+
+ switch (exp->action) {
+ case ACT_ALLOW:
+ txn->flags |= TX_CLALLOW;
+ done = 1;
+ break;
+
+ case ACT_DENY:
+ txn->flags |= TX_CLDENY;
+ done = 1;
+ break;
+
+ case ACT_TARPIT:
+ txn->flags |= TX_CLTARPIT;
+ done = 1;
+ break;
+
+ case ACT_REPLACE:
+ len = exp_replace(trash.area, trash.size, reqline->area, exp->replace, pmatch);
+ if (len < 0)
+ return -1;
+
+ http_parse_stline(ist2(trash.area, len),
+ &sl.rq.m, &sl.rq.u, &sl.rq.v);
+ sl.rq.meth = find_http_meth(sl.rq.m.ptr, sl.rq.m.len);
+
+ if (!http_replace_reqline(htx, sl))
+ return -1;
+ done = 1;
+ break;
+ }
+ }
+ return done;
+}
+
+/*
+ * Apply all the req filters of proxy <px> to all headers in buffer <req> of stream <s>.
+ * Returns 0 if everything is alright, or -1 in case a replacement lead to an
+ * unparsable request. Since it can manage the switch to another backend, it
+ * updates the per-proxy DENY stats.
+ */
+static int htx_apply_filters_to_request(struct stream *s, struct channel *req, struct proxy *px)
+{
+ struct session *sess = s->sess;
+ struct http_txn *txn = s->txn;
+ struct hdr_exp *exp;
+
+ for (exp = px->req_exp; exp; exp = exp->next) {
+ int ret;
+
+ /*
+ * The interleaving of transformations and verdicts
+ * makes it difficult to decide to continue or stop
+ * the evaluation.
+ */
+
+ if (txn->flags & (TX_CLDENY|TX_CLTARPIT))
+ break;
+
+ if ((txn->flags & TX_CLALLOW) &&
+ (exp->action == ACT_ALLOW || exp->action == ACT_DENY ||
+ exp->action == ACT_TARPIT || exp->action == ACT_PASS))
+ continue;
+
+ /* if this filter had a condition, evaluate it now and skip to
+ * next filter if the condition does not match.
+ */
+ if (exp->cond) {
+ ret = acl_exec_cond(exp->cond, px, sess, s, SMP_OPT_DIR_REQ|SMP_OPT_FINAL);
+ ret = acl_pass(ret);
+ if (((struct acl_cond *)exp->cond)->pol == ACL_COND_UNLESS)
+ ret = !ret;
+
+ if (!ret)
+ continue;
+ }
+
+ /* Apply the filter to the request line. */
+ ret = htx_apply_filter_to_req_line(s, req, exp);
+ if (unlikely(ret < 0))
+ return -1;
+
+ if (likely(ret == 0)) {
+ /* The filter did not match the request, it can be
+ * iterated through all headers.
+ */
+ if (unlikely(htx_apply_filter_to_req_headers(s, req, exp) < 0))
+ return -1;
+ }
+ }
+ return 0;
+}
+
+/* Iterate the same filter through all response headers contained in <res>.
+ * Returns 1 if this filter can be stopped upon return, otherwise 0.
+ */
+static int htx_apply_filter_to_resp_headers(struct stream *s, struct channel *res, struct hdr_exp *exp)
+{
+ struct http_txn *txn = s->txn;
+ struct htx *htx;
+ struct buffer *hdr = get_trash_chunk();
+ int32_t pos;
+
+ htx = htx_from_buf(&res->buf);
+
+ for (pos = htx_get_head(htx); pos != -1; pos = htx_get_next(htx, pos)) {
+ struct htx_blk *blk = htx_get_blk(htx, pos);
+ enum htx_blk_type type;
+ struct ist n, v;
+
+ next_hdr:
+ type = htx_get_blk_type(blk);
+ if (type == HTX_BLK_EOH)
+ break;
+ if (type != HTX_BLK_HDR)
+ continue;
+
+ if (unlikely(txn->flags & TX_SVDENY))
+ return 1;
+ else if (unlikely(txn->flags & TX_SVALLOW) &&
+ (exp->action == ACT_ALLOW ||
+ exp->action == ACT_DENY))
+ return 0;
+
+ n = htx_get_blk_name(htx, blk);
+ v = htx_get_blk_value(htx, blk);
+
+ chunk_memcat(hdr, n.ptr, n.len);
+ hdr->area[hdr->data++] = ':';
+ hdr->area[hdr->data++] = ' ';
+ chunk_memcat(hdr, v.ptr, v.len);
+
+ /* Now we have one header in <hdr> */
+
+ if (regex_exec_match2(exp->preg, hdr->area, hdr->data, MAX_MATCH, pmatch, 0)) {
+ struct http_hdr_ctx ctx;
+ int len;
+
+ switch (exp->action) {
+ case ACT_ALLOW:
+ txn->flags |= TX_SVALLOW;
+ goto end;
+ break;
+
+ case ACT_DENY:
+ txn->flags |= TX_SVDENY;
+ goto end;
+ break;
+
+ case ACT_REPLACE:
+ len = exp_replace(trash.area, trash.size, hdr->area, exp->replace, pmatch);
+ if (len < 0)
+ return -1;
+
+ http_parse_header(ist2(trash.area, len), &n, &v);
+ ctx.blk = blk;
+ ctx.value = v;
+ if (!http_replace_header(htx, &ctx, n, v))
+ return -1;
+ if (!ctx.blk)
+ goto end;
+ pos = htx_get_blk_pos(htx, blk);
+ break;
+
+ case ACT_REMOVE:
+ ctx.blk = blk;
+ ctx.value = v;
+ if (!http_remove_header(htx, &ctx))
+ return -1;
+ if (!ctx.blk)
+ goto end;
+ pos = htx_get_blk_pos(htx, blk);
+ goto next_hdr;
+ }
+ }
+
+ }
+ end:
+ return 0;
+}
+
+/* Apply the filter to the status line in the response buffer <res>.
+ * Returns 0 if nothing has been done, 1 if the filter has been applied,
+ * or -1 if a replacement resulted in an invalid status line.
+ */
+static int htx_apply_filter_to_sts_line(struct stream *s, struct channel *res, struct hdr_exp *exp)
+{
+ struct http_txn *txn = s->txn;
+ struct htx *htx;
+ struct buffer *resline = get_trash_chunk();
+ int done;
+
+ htx = htx_from_buf(&res->buf);
+
+ if (unlikely(txn->flags & TX_SVDENY))
+ return 1;
+ else if (unlikely(txn->flags & TX_SVALLOW) &&
+ (exp->action == ACT_ALLOW ||
+ exp->action == ACT_DENY))
+ return 0;
+ else if (exp->action == ACT_REMOVE)
+ return 0;
+
+ done = 0;
+ resline->data = htx_fmt_res_line(http_find_stline(htx), resline->area, resline->size);
+
+ /* Now we have the status line between cur_ptr and cur_end */
+ if (regex_exec_match2(exp->preg, resline->area, resline->data, MAX_MATCH, pmatch, 0)) {
+ union h1_sl sl;
+ int len;
+
+ switch (exp->action) {
+ case ACT_ALLOW:
+ txn->flags |= TX_SVALLOW;
+ done = 1;
+ break;
+
+ case ACT_DENY:
+ txn->flags |= TX_SVDENY;
+ done = 1;
+ break;
+
+ case ACT_REPLACE:
+ len = exp_replace(trash.area, trash.size, resline->area, exp->replace, pmatch);
+ if (len < 0)
+ return -1;
+
+ http_parse_stline(ist2(trash.area, len),
+ &sl.st.v, &sl.st.c, &sl.st.r);
+ sl.st.status = strl2ui(sl.st.c.ptr, sl.st.c.len);
+
+ if (!http_replace_resline(htx, sl))
+ return -1;
+
+ done = 1;
+ return 1;
+ }
+ }
+ return done;
+}
+
+/*
+ * Apply all the resp filters of proxy <px> to all headers in buffer <res> of stream <s>.
+ * Returns 0 if everything is alright, or -1 in case a replacement lead to an
+ * unparsable response.
+ */
+static int htx_apply_filters_to_response(struct stream *s, struct channel *res, struct proxy *px)
+{
+ struct session *sess = s->sess;
+ struct http_txn *txn = s->txn;
+ struct hdr_exp *exp;
+
+ for (exp = px->rsp_exp; exp; exp = exp->next) {
+ int ret;
+
+ /*
+ * The interleaving of transformations and verdicts
+ * makes it difficult to decide to continue or stop
+ * the evaluation.
+ */
+
+ if (txn->flags & TX_SVDENY)
+ break;
+
+ if ((txn->flags & TX_SVALLOW) &&
+ (exp->action == ACT_ALLOW || exp->action == ACT_DENY ||
+ exp->action == ACT_PASS)) {
+ exp = exp->next;
+ continue;
+ }
+
+ /* if this filter had a condition, evaluate it now and skip to
+ * next filter if the condition does not match.
+ */
+ if (exp->cond) {
+ ret = acl_exec_cond(exp->cond, px, sess, s, SMP_OPT_DIR_RES|SMP_OPT_FINAL);
+ ret = acl_pass(ret);
+ if (((struct acl_cond *)exp->cond)->pol == ACL_COND_UNLESS)
+ ret = !ret;
+ if (!ret)
+ continue;
+ }
+
+ /* Apply the filter to the status line. */
+ ret = htx_apply_filter_to_sts_line(s, res, exp);
+ if (unlikely(ret < 0))
+ return -1;
+
+ if (likely(ret == 0)) {
+ /* The filter did not match the response, it can be
+ * iterated through all headers.
+ */
+ if (unlikely(htx_apply_filter_to_resp_headers(s, res, exp) < 0))
+ return -1;
+ }
+ }
+ return 0;
+}
+
/* This function terminates the request because it was completly analyzed or
* because an error was triggered during the body forwarding.
*/