nghttpx: Handle edge case wildcard pattern and add tests

Suppose the wildcard patterns follows:

- *.nghttp2.org/foo
- *.img.nghttp2.org/bar

Previously, s.img.nghttp2.org/foo does not match anything.  Now it
matches first pattern.

src/CMakeLists.txt

@@ -149,6 +149,7 @@ if(ENABLE_APP)
       shrpx_config_test.cc
       shrpx_worker_test.cc
       shrpx_http_test.cc
+      shrpx_router_test.cc
       http2_test.cc
       util_test.cc
       nghttp2_gzip_test.c

src/Makefile.am

@@ -175,6 +175,7 @@ nghttpx_unittest_SOURCES = shrpx-unittest.cc \
 	shrpx_config_test.cc shrpx_config_test.h \
 	shrpx_worker_test.cc shrpx_worker_test.h \
 	shrpx_http_test.cc shrpx_http_test.h \
+	shrpx_router_test.cc shrpx_router_test.h \
 	http2_test.cc http2_test.h \
 	util_test.cc util_test.h \
 	nghttp2_gzip_test.c nghttp2_gzip_test.h \

src/shrpx-unittest.cc

@@ -44,6 +44,7 @@
 #include "base64_test.h"
 #include "shrpx_config.h"
 #include "ssl.h"
+#include "shrpx_router_test.h"
 
 static int init_suite1(void) { return 0; }
 
@@ -125,6 +126,9 @@ int main(int argc, char *argv[]) {
                    shrpx::test_shrpx_http_create_forwarded) ||
       !CU_add_test(pSuite, "http_create_via_header_value",
                    shrpx::test_shrpx_http_create_via_header_value) ||
+      !CU_add_test(pSuite, "router_match", shrpx::test_shrpx_router_match) ||
+      !CU_add_test(pSuite, "router_match_prefix",
+                   shrpx::test_shrpx_router_match_prefix) ||
       !CU_add_test(pSuite, "util_streq", shrpx::test_util_streq) ||
       !CU_add_test(pSuite, "util_strieq", shrpx::test_util_strieq) ||
       !CU_add_test(pSuite, "util_inp_strlower",

src/shrpx_router.cc

@@ -280,7 +280,7 @@ ssize_t Router::match(const StringRef &host, const StringRef &path) const {
 }
 
 namespace {
-const RNode *match_prefix(const RNode *node, const char *first,
+const RNode *match_prefix(size_t *nread, const RNode *node, const char *first,
                           const char *last) {
   if (first == last) {
     return nullptr;
@@ -288,45 +288,53 @@ const RNode *match_prefix(const RNode *node, const char *first,
 
   auto p = first;
 
-  const RNode *ans = nullptr;
-
   for (;;) {
     auto next_node = find_next_node(node, *p);
     if (next_node == nullptr) {
-      return ans;
+      return nullptr;
     }
 
     node = next_node;
 
     auto n = std::min(node->len, static_cast<size_t>(last - p));
     if (memcmp(node->s, p, n) != 0) {
-      return ans;
+      return nullptr;
     }
 
     p += n;
 
     if (p != last) {
       if (node->index != -1) {
-        ans = node;
+        *nread = p - first;
+        return node;
       }
       continue;
     }
 
     if (node->len == n) {
+      *nread = p - first;
       return node;
     }
 
-    return ans;
+    return nullptr;
   }
 }
 } // namespace
 
-ssize_t Router::match_prefix(const StringRef &s) const {
+ssize_t Router::match_prefix(size_t *nread, const RNode **last_node,
-  auto node = ::shrpx::match_prefix(&root_, std::begin(s), std::end(s));
+                             const StringRef &s) const {
+  if (*last_node == nullptr) {
+    *last_node = &root_;
+  }
+
+  auto node =
+      ::shrpx::match_prefix(nread, *last_node, std::begin(s), std::end(s));
   if (node == nullptr) {
     return -1;
   }
 
+  *last_node = node;
+
   return node->index;
 }
 

src/shrpx_router.h

@@ -68,8 +68,15 @@ public:
   // Returns the matched index of pattern.  -1 if there is no match.
   ssize_t match(const StringRef &host, const StringRef &path) const;
   // Returns the matched index of pattern if a pattern is a suffix of
-  // |s|, otherwise -1.
+  // |s|, otherwise -1.  If |*last_node| is not nullptr, it specifies
-  ssize_t match_prefix(const StringRef &s) const;
+  // the first node to start matching.  If it is nullptr, match will
+  // start from scratch.  When the match was found (the return value
+  // is not -1), |*nread| has the number of bytes matched in |s|, and
+  // |*last_node| has the last matched node.  One can continue to
+  // match the longer pattern using the returned |*last_node| to the
+  // another invocation of this function until it returns -1.
+  ssize_t match_prefix(size_t *nread, const RNode **last_node,
+                       const StringRef &s) const;
 
   void add_node(RNode *node, const char *pattern, size_t patlen, size_t index);
 

src/shrpx_router_test.cc

@@ -0,0 +1,129 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2016 Tatsuhiro Tsujikawa
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include "shrpx_router_test.h"
+
+#include <CUnit/CUnit.h>
+
+#include "shrpx_router.h"
+
+namespace shrpx {
+
+struct Pattern {
+  StringRef pattern;
+  size_t idx;
+};
+
+void test_shrpx_router_match(void) {
+  auto patterns = std::vector<Pattern>{
+      {StringRef::from_lit("nghttp2.org/"), 0},
+      {StringRef::from_lit("nghttp2.org/alpha"), 1},
+      {StringRef::from_lit("nghttp2.org/alpha/"), 2},
+      {StringRef::from_lit("nghttp2.org/alpha/bravo/"), 3},
+      {StringRef::from_lit("www.nghttp2.org/alpha/"), 4},
+      {StringRef::from_lit("/alpha"), 5},
+      {StringRef::from_lit("example.com/alpha/"), 6},
+  };
+
+  Router router;
+
+  for (auto &p : patterns) {
+    router.add_route(p.pattern, p.idx);
+  }
+
+  ssize_t idx;
+
+  idx = router.match(StringRef::from_lit("nghttp2.org"),
+                     StringRef::from_lit("/"));
+
+  CU_ASSERT(0 == idx);
+
+  idx = router.match(StringRef::from_lit("nghttp2.org"),
+                     StringRef::from_lit("/alpha"));
+
+  CU_ASSERT(1 == idx);
+
+  idx = router.match(StringRef::from_lit("nghttp2.org"),
+                     StringRef::from_lit("/alpha/"));
+
+  CU_ASSERT(2 == idx);
+
+  idx = router.match(StringRef::from_lit("nghttp2.org"),
+                     StringRef::from_lit("/alpha/charlie"));
+
+  CU_ASSERT(2 == idx);
+
+  idx = router.match(StringRef::from_lit("nghttp2.org"),
+                     StringRef::from_lit("/alpha/bravo/"));
+
+  CU_ASSERT(3 == idx);
+
+  // matches pattern when last '/' is missing in path
+  idx = router.match(StringRef::from_lit("nghttp2.org"),
+                     StringRef::from_lit("/alpha/bravo"));
+
+  idx = router.match(StringRef{}, StringRef::from_lit("/alpha"));
+
+  CU_ASSERT(5 == idx);
+}
+
+void test_shrpx_router_match_prefix(void) {
+  auto patterns = std::vector<Pattern>{
+      {StringRef::from_lit("gro.2ptthgn."), 0},
+      {StringRef::from_lit("gro.2ptthgn.www."), 1},
+      {StringRef::from_lit("gro.2ptthgn.gmi."), 2},
+      {StringRef::from_lit("gro.2ptthgn.gmi.ahpla."), 3},
+  };
+
+  Router router;
+
+  for (auto &p : patterns) {
+    router.add_route(p.pattern, p.idx);
+  }
+
+  ssize_t idx;
+  const RNode *node;
+  size_t nread;
+
+  node = nullptr;
+
+  idx = router.match_prefix(&nread, &node,
+                            StringRef::from_lit("gro.2ptthgn.gmi.ahpla.ovarb"));
+
+  CU_ASSERT(0 == idx);
+  CU_ASSERT(12 == nread);
+
+  idx = router.match_prefix(&nread, &node,
+                            StringRef::from_lit("gmi.ahpla.ovarb"));
+
+  CU_ASSERT(2 == idx);
+  CU_ASSERT(4 == nread);
+
+  idx = router.match_prefix(&nread, &node, StringRef::from_lit("ahpla.ovarb"));
+
+  CU_ASSERT(3 == idx);
+  CU_ASSERT(6 == nread);
+}
+
+} // namespace shrpx

src/shrpx_router_test.h

@@ -0,0 +1,39 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2016 Tatsuhiro Tsujikawa
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef SHRPX_ROUTER_TEST_H
+#define SHRPX_ROUTER_TEST_H
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif // HAVE_CONFIG_H
+
+namespace shrpx {
+
+void test_shrpx_router_match(void);
+void test_shrpx_router_match_prefix(void);
+
+} // namespace shrpx
+
+#endif // SHRPX_ROUTER_TEST_H

src/shrpx_worker.cc

@@ -488,12 +488,23 @@ size_t match_downstream_addr_group_host(
   }
 
   if (!wildcard_patterns.empty() && !host.empty()) {
-    auto rev_host = std::string{std::begin(host) + 1, std::end(host)};
+    auto rev_host_src = std::string{std::begin(host) + 1, std::end(host)};
-    std::reverse(std::begin(rev_host), std::end(rev_host));
+    std::reverse(std::begin(rev_host_src), std::end(rev_host_src));
+
+    ssize_t best_group = -1;
+    const RNode *last_node = nullptr;
+    auto rev_host = StringRef{std::begin(rev_host_src), std::end(rev_host_src)};
+
+    for (;;) {
+      size_t nread = 0;
+      auto wcidx =
+          rev_wildcard_router.match_prefix(&nread, &last_node, rev_host);
+      if (wcidx == -1) {
+        break;
+      }
+
+      rev_host = StringRef{std::begin(rev_host) + nread, std::end(rev_host)};
 
-    auto wcidx = rev_wildcard_router.match_prefix(
-        StringRef{std::begin(rev_host), std::end(rev_host)});
-    if (wcidx != -1) {
       auto &wc = wildcard_patterns[wcidx];
       auto group = wc.router.match(StringRef{}, path);
       if (group != -1) {
@@ -503,9 +514,14 @@ size_t match_downstream_addr_group_host(
           LOG(INFO) << "Found wildcard pattern with query " << host << path
                     << ", matched pattern=" << groups[group]->pattern;
         }
-        return group;
+
+        best_group = group;
       }
     }
+
+    if (best_group != -1) {
+      return best_group;
+    }
   }
 
   group = router.match(StringRef::from_lit(""), path);