src: support LINK/UNLINK (RFC 2068, draft-snell-link-method)

Add support for HTTP methods LINK and UNLINK originally defined in RFC2068
section 19.6.2.2, but with semantic added in a Internet draft.
https://tools.ietf.org/html/rfc2068#section-19.6.1.2
https://tools.ietf.org/html/draft-snell-link-method-12

Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Fedor Induty <fedor@indutny.com>
PR-URL: https://github.com/nodejs/http-parser/pull/267

AUTHORS

@@ -65,3 +65,4 @@ Romain Giraud <giraud.romain@gmail.com>
 Jay Satiro <raysatiro@yahoo.com>
 Arne Steen <Arne.Steen@gmx.de>
 Kjell Schubert <kjell.schubert@gmail.com>
+Olivier Mengué <dolmen@cpan.org>

http_parser.c

@@ -965,7 +965,7 @@ reexecute:
           case 'D': parser->method = HTTP_DELETE; break;
           case 'G': parser->method = HTTP_GET; break;
           case 'H': parser->method = HTTP_HEAD; break;
-          case 'L': parser->method = HTTP_LOCK; break;
+          case 'L': parser->method = HTTP_LOCK; /* or LINK */ break;
           case 'M': parser->method = HTTP_MKCOL; /* or MOVE, MKACTIVITY, MERGE, M-SEARCH, MKCALENDAR */ break;
           case 'N': parser->method = HTTP_NOTIFY; break;
           case 'O': parser->method = HTTP_OPTIONS; break;
@@ -975,7 +975,7 @@ reexecute:
           case 'R': parser->method = HTTP_REPORT; /* or REBIND */ break;
           case 'S': parser->method = HTTP_SUBSCRIBE; /* or SEARCH */ break;
           case 'T': parser->method = HTTP_TRACE; break;
-          case 'U': parser->method = HTTP_UNLOCK; /* or UNSUBSCRIBE, UNBIND */ break;
+          case 'U': parser->method = HTTP_UNLOCK; /* or UNSUBSCRIBE, UNBIND, UNLINK */ break;
           default:
             SET_ERRNO(HPE_INVALID_METHOD);
             goto error;
@@ -1038,7 +1038,8 @@ reexecute:
               SET_ERRNO(HPE_INVALID_METHOD);
               goto error;
             }
-        } else if (parser->index == 1 && parser->method == HTTP_POST) {
+        } else if (parser->index == 1) {
+          if (parser->method == HTTP_POST) {
             if (ch == 'R') {
               parser->method = HTTP_PROPFIND; /* or HTTP_PROPPATCH */
             } else if (ch == 'U') {
@@ -1049,6 +1050,14 @@ reexecute:
               SET_ERRNO(HPE_INVALID_METHOD);
               goto error;
             }
+          } else if (parser->method == HTTP_LOCK) {
+            if (ch == 'I') {
+              parser->method = HTTP_LINK;
+            } else {
+              SET_ERRNO(HPE_INVALID_METHOD);
+              goto error;
+            }
+          }
         } else if (parser->index == 2) {
           if (parser->method == HTTP_PUT) {
             if (ch == 'R') {
@@ -1072,6 +1081,8 @@ reexecute:
           }
         } else if (parser->index == 4 && parser->method == HTTP_PROPFIND && ch == 'P') {
           parser->method = HTTP_PROPPATCH;
+        } else if (parser->index == 3 && parser->method == HTTP_UNLOCK && ch == 'I') {
+          parser->method = HTTP_UNLINK;
         } else {
           SET_ERRNO(HPE_INVALID_METHOD);
           goto error;

http_parser.h

@@ -124,6 +124,9 @@ typedef int (*http_cb) (http_parser*);
   XX(29, PURGE,       PURGE)        \
   /* CalDAV */                      \
   XX(30, MKCALENDAR,  MKCALENDAR)   \
+  /* RFC-2068, section 19.6.1.2 */  \
+  XX(31, LINK,        LINK)         \
+  XX(32, UNLINK,      UNLINK)       \
 
 enum http_method
   {

test.c

@@ -1101,6 +1101,58 @@ const struct message requests[] =
   ,.body= ""
   }
 
+/* Examples from the Internet draft for LINK/UNLINK methods:
+ * https://tools.ietf.org/id/draft-snell-link-method-01.html#rfc.section.5
+ */
+
+#define LINK_REQUEST 40
+, {.name = "link request"
+  ,.type= HTTP_REQUEST
+  ,.raw= "LINK /images/my_dog.jpg HTTP/1.1\r\n"
+         "Host: example.com\r\n"
+         "Link: <http://example.com/profiles/joe>; rel=\"tag\"\r\n"
+         "Link: <http://example.com/profiles/sally>; rel=\"tag\"\r\n"
+         "\r\n"
+  ,.should_keep_alive= TRUE
+  ,.message_complete_on_eof= FALSE
+  ,.http_major= 1
+  ,.http_minor= 1
+  ,.method= HTTP_LINK
+  ,.request_path= "/images/my_dog.jpg"
+  ,.request_url= "/images/my_dog.jpg"
+  ,.query_string= ""
+  ,.fragment= ""
+  ,.num_headers= 3
+  ,.headers= { { "Host", "example.com" }
+             , { "Link", "<http://example.com/profiles/joe>; rel=\"tag\"" }
+	     , { "Link", "<http://example.com/profiles/sally>; rel=\"tag\"" }
+             }
+  ,.body= ""
+  }
+
+#define UNLINK_REQUEST 41
+, {.name = "link request"
+  ,.type= HTTP_REQUEST
+  ,.raw= "UNLINK /images/my_dog.jpg HTTP/1.1\r\n"
+         "Host: example.com\r\n"
+         "Link: <http://example.com/profiles/sally>; rel=\"tag\"\r\n"
+         "\r\n"
+  ,.should_keep_alive= TRUE
+  ,.message_complete_on_eof= FALSE
+  ,.http_major= 1
+  ,.http_minor= 1
+  ,.method= HTTP_UNLINK
+  ,.request_path= "/images/my_dog.jpg"
+  ,.request_url= "/images/my_dog.jpg"
+  ,.query_string= ""
+  ,.fragment= ""
+  ,.num_headers= 2
+  ,.headers= { { "Host", "example.com" }
+	     , { "Link", "<http://example.com/profiles/sally>; rel=\"tag\"" }
+             }
+  ,.body= ""
+  }
+
 , {.name= NULL } /* sentinel */
 };
 
@@ -3760,6 +3812,8 @@ main (void)
     "PATCH",
     "PURGE",
     "MKCALENDAR",
+    "LINK",
+    "UNLINK",
     0 };
   const char **this_method;
   for (this_method = all_methods; *this_method; this_method++) {