1 files changed, 97 insertions, 0 deletions
diff --git a/src/cfgdiag.c b/src/cfgdiag.c
new file mode 100644
index 0000000..f8e4a9e
--- /dev/null
+++ b/src/cfgdiag.c
@@ -0,0 +1,97 @@
+#include <stdarg.h>
+#include <stdlib.h>
+
+#include <import/ebistree.h>
+
+#include <haproxy/cfgdiag.h>
+#include <haproxy/log.h>
+#include <haproxy/proxy.h>
+#include <haproxy/server.h>
+
+/* Use this function to emit diagnostic.
+ * This can be used as a shortcut to set value pointed by <ret> to 1 at the
+ * same time.
+ */
+static inline void diag_warning(int *ret, char *fmt, ...)
+{
+	va_list argp;
+
+	va_start(argp, fmt);
+	*ret = 1;
+	_ha_vdiag_warning(fmt, argp);
+	va_end(argp);
+}
+
+/* Use this for dynamic allocation in diagnostics.
+ * In case of allocation failure, this will immediately terminates haproxy.
+ */
+static inline void *diag_alloc(size_t size)
+{
+	void *out = NULL;
+
+	if (!(out = malloc(size))) {
+		fprintf(stderr, "out of memory\n");
+		exit(1);
+	}
+
+	return out;
+}
+
+/* Checks that two servers from the same backend does not share the same cookie
+ * value. Backup servers are not taken into account as it can be quite common to
+ * share cookie values in this case.
+ */
+static void check_server_cookies(int *ret)
+{
+	struct cookie_entry {
+		struct ebpt_node node;
+	};
+
+	struct proxy  *px;
+	struct server *srv;
+
+	struct eb_root cookies_tree = EB_ROOT_UNIQUE;
+	struct ebpt_node *cookie_node;
+	struct cookie_entry *cookie_entry;
+	struct ebpt_node *node;
+
+	for (px = proxies_list; px; px = px->next) {
+		for (srv = px->srv; srv; srv = srv->next) {
+			/* do not take into account backup servers */
+			if (!srv->cookie || (srv->flags & SRV_F_BACKUP))
+				continue;
+
+			cookie_node = ebis_lookup(&cookies_tree, srv->cookie);
+			if (cookie_node) {
+				diag_warning(ret, "parsing [%s:%d] : 'server %s' : same cookie value is set for a previous non-backup server in the same backend, it may break connection persistence\n",
+				             srv->conf.file, srv->conf.line, srv->id);
+				continue;
+			}
+
+			cookie_entry = diag_alloc(sizeof(*cookie_entry));
+			cookie_entry->node.key = srv->cookie;
+			ebis_insert(&cookies_tree, &cookie_entry->node);
+		}
+
+		/* clear the tree and free its entries */
+		while ((node = ebpt_first(&cookies_tree))) {
+			cookie_entry = ebpt_entry(node, struct cookie_entry, node);
+			eb_delete(&node->node);
+			free(cookie_entry);
+		}
+	}
+}
+
+/* Placeholder to execute various diagnostic checks after the configuration file
+ * has been fully parsed. It will output a warning for each diagnostic found.
+ *
+ * Returns 0 if no diagnostic message has been found else 1.
+ */
+int cfg_run_diagnostics()
+{
+	int ret = 0;
+
+	check_server_cookies(&ret);
+
+	return ret;
+}