# HG changeset patch
# User Vladimir Homutov <vl@nginx.com>
# Date 1615824338 -10800
# Node ID 1a489587e1c863cdf070c99dd4f3e88406348d9e
# Parent  5cb5b568282b26fee1f58f68e8d0d261d77db019
QUIC: fixed key extraction in bpf.

In case of long header packets, dcid length was not read correctly.

While there, macros to parse uint64 was fixed as well as format specifiers
to print it in debug mode.

Thanks to Gao Yan <gaoyan09@baidu.com>.

diff --git a/src/event/quic/bpf/ngx_quic_reuseport_helper.c b/src/event/quic/bpf/ngx_quic_reuseport_helper.c
--- a/src/event/quic/bpf/ngx_quic_reuseport_helper.c
+++ b/src/event/quic/bpf/ngx_quic_reuseport_helper.c
@@ -58,10 +58,10 @@ char _license[] SEC("license") = LICENSE
      ((__u64)(p)[1] << 48) |                                                  \
      ((__u64)(p)[2] << 40) |                                                  \
      ((__u64)(p)[3] << 32) |                                                  \
-             (p)[4] << 24  |                                                  \
-             (p)[5] << 16  |                                                  \
-             (p)[6] << 8   |                                                  \
-             (p)[7])
+     ((__u64)(p)[4] << 24) |                                                  \
+     ((__u64)(p)[5] << 16) |                                                  \
+     ((__u64)(p)[6] << 8)  |                                                  \
+     ((__u64)(p)[7]))
 
 /*
  * actual map object is created by the "bpf" system call,
@@ -82,12 +82,14 @@ int ngx_quic_select_socket_by_dcid(struc
     end = (unsigned char *) ctx->data_end;
     offset = 0;
 
-    advance_data(sizeof(struct udphdr)); /* skip UDP header */
-    advance_data(1); /* QUIC flags */
+    advance_data(sizeof(struct udphdr)); /* data at UDP header */
+    advance_data(1); /* data at QUIC flags */
 
     if (data[0] & NGX_QUIC_PKT_LONG) {
 
-        advance_data(4); /* skip QUIC version */
+        advance_data(4); /* data at QUIC version */
+        advance_data(1); /* data at DCID len */
+
         len = data[0];   /* read DCID length */
 
         if (len < 8) {
@@ -95,8 +97,6 @@ int ngx_quic_select_socket_by_dcid(struc
             return SK_PASS;
         }
 
-        advance_data(1); /* skip DCID len */
-
     } else {
         len = NGX_QUIC_SERVER_CID_LEN;
     }
@@ -115,17 +115,17 @@ int ngx_quic_select_socket_by_dcid(struc
 
     switch (rc) {
     case 0:
-        debugmsg("nginx quic socket selected by key 0x%x", key);
+        debugmsg("nginx quic socket selected by key 0x%llx", key);
         return SK_PASS;
 
     /* kernel returns positive error numbers, errno.h defines positive */
     case -ENOENT:
-        debugmsg("nginx quic default route for key 0x%x", key);
+        debugmsg("nginx quic default route for key 0x%llx", key);
         /* let the default reuseport logic decide which socket to choose */
         return SK_PASS;
 
     default:
-        debugmsg("nginx quic bpf_sk_select_reuseport err: %d key 0x%x",
+        debugmsg("nginx quic bpf_sk_select_reuseport err: %d key 0x%llx",
                   rc, key);
         goto failed;
     }