add support for the proxy protocol v1

This allows to use proxies like nginx or haproxy in front of gmid and
still have the correct information about the originating client.

This will need explicit opt-in via the `proxy-v1' listen flag which
will be added in a follow-up commit.

Merges https://github.com/omar-polo/gmid/pull/30

1 files changed, 45 insertions, 9 deletions

diff --git a/gmid.h b/gmid.h
index 112a029..7819cb1 100644
--- a/gmid.h
+++ b/gmid.h
@@ -34,6 +34,7 @@
 #include <time.h>
 #include <tls.h>
 #include <unistd.h>
+#include <assert.h>
 
 #include <openssl/x509.h>
 
@@ -59,6 +60,8 @@
 
 #define GMID_VERSION	"gmid/" VERSION
 
+#define ASSERT_MSG(expr, msg) assert(((void)msg, (expr)))
+
 #define GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
 
 #define SUCCESS		20
@@ -281,17 +284,44 @@ enum {
 	REQUEST_DONE,
 };
 
+enum proto {
+	PROTO_V4,
+	PROTO_V6,
+	PROTO_UNKNOWN,
+};
+
+struct proxy_protocol_v1 {
+	enum proto proto;
+	union {
+		struct in_addr v4;
+		struct in6_addr v6;
+	} srcaddr, dstaddr;
+	uint16_t srcport, dstport;
+};
+
+#define BUFLAYER_MAX 108
+
+struct buflayer
+{
+	char data[BUFLAYER_MAX];
+	size_t len;
+	ssize_t read_pos;
+	int has_tail;
+};
+
 struct client {
-	struct conf	*conf;
+	struct conf		*conf;
 	struct address	*addr;
-	uint32_t	 id;
-	struct tls	*ctx;
-	char		*req;
-	size_t		 reqlen;
-	struct iri	 iri;
-	char		 domain[DOMAIN_NAME_LEN];
-	char		 rhost[NI_MAXHOST];
-	char		 rserv[NI_MAXSERV];
+	int 		 	 should_buffer;
+	struct buflayer  buf;
+	uint32_t	 	 id;
+	struct tls		*ctx;
+	char			*req;
+	size_t		 	 reqlen;
+	struct iri	 	 iri;
+	char		 	 domain[DOMAIN_NAME_LEN];
+	char		 	 rhost[NI_MAXHOST];
+	char		 	 rserv[NI_MAXSERV];
 
 	struct bufferevent *bev;
 
@@ -464,4 +494,10 @@ struct vhost	*new_vhost(void);
 struct location	*new_location(void);
 struct proxy	*new_proxy(void);
 
+/* proxy-proto.c */
+#define PROXY_PROTO_PARSE_FAIL -1
+#define PROXY_PROTO_PARSE_SUCCESS 0
+int proxy_proto_v1_parse(struct proxy_protocol_v1 *, char *, size_t, size_t *);
+int proxy_proto_v1_string(const struct proxy_protocol_v1 *, char*, size_t);
+
 #endif