Fixes #85

Removing code for absolute symlinks which point outside root.
little-bear-labs · Jan 17, 2024 · 190e2d1 · 190e2d1
1 parent 5aec6e9
commit 190e2d1
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Showing 9 changed files with 20 additions and 238 deletions.
diff --git a/library/include/ipfs_client/multi_hash.h b/library/include/ipfs_client/multi_hash.h
@@ -7,6 +7,8 @@
 
 namespace ipfs {
 enum class HashType { INVALID = -1, IDENTITY = 0, SHA2_256 = 0X12 };
+constexpr std::uint16_t MaximumHashLength = 127;
+
 HashType Validate(HashType);
 std::string_view GetName(HashType);
 class MultiHash {

diff --git a/library/include/libp2p/multi/content_identifier.hpp b/library/include/libp2p/multi/content_identifier.hpp
diff --git a/library/include/libp2p/multi/content_identifier_codec.hpp b/library/include/libp2p/multi/content_identifier_codec.hpp
diff --git a/library/src/ipfs_client/cid.cc b/library/src/ipfs_client/cid.cc
@@ -24,7 +24,7 @@ Self::Cid(std::string_view s) {
       assign(bytes.value());
     }
   } else {
-    LOG(ERROR) << "Failed to decode the multibase for a CID: " << s;
+    LOG(WARNING) << "Failed to decode the multibase for a CID: " << s;
   }
 }
 

diff --git a/library/src/ipfs_client/dag_block_unittest.cc b/library/src/ipfs_client/dag_block_unittest.cc
@@ -99,4 +99,4 @@ TEST(BlockTest, TypeNames) {
   EXPECT_EQ(Stringify(T::FileChunk), "FileChunk");
   EXPECT_EQ(Stringify(T::NonFs), "NonFs");
   EXPECT_EQ(Stringify(T::Invalid), "Invalid");
-}
+}
diff --git a/library/src/ipfs_client/identity_cid.cc b/library/src/ipfs_client/identity_cid.cc
@@ -1,14 +1,11 @@
 #include <ipfs_client/identity_cid.h>
 
-#include <libp2p/multi/multihash.hpp>
-
 #include <log_macros.h>
 
 namespace Self = ipfs::id_cid;
-namespace m = libp2p::multi;
 
 auto Self::forText(std::string_view txt) -> Cid {
-  txt = txt.substr(0UL, m::Multihash::kMaxHashLength);
+  txt = txt.substr(0UL, MaximumHashLength);
   auto p = reinterpret_cast<Byte const*>(txt.data());
   auto b = ByteView{p, txt.size()};
   MultiHash mh(HashType::IDENTITY, b);

diff --git a/library/src/ipfs_client/ipld/symlink.cc b/library/src/ipfs_client/ipld/symlink.cc
@@ -4,33 +4,24 @@
 
 using Self = ipfs::ipld::Symlink;
 
-Self::Symlink(std::string target)
-    : style_{from_target(target)}, target_{target} {}
+Self::Symlink(std::string target) : target_{target} {}
 
 Self::~Symlink() {}
 
 auto Self::resolve(SlashDelimited path, BlockLookup, std::string& to_here)
     -> ResolveResult {
   std::string result;
-  switch (style_) {
-    case Style::Absolute:
-      result.assign(target_);
-      LOG(INFO) << "Absolute symlink '" << target_ << "' ...";
-      break;
-    case Style::Relative: {
-      auto c = to_here.find_last_not_of('/');
-      c = to_here.find_last_of('/', c);
-      DCHECK(c != to_here.size()) << to_here;
+  if (is_absolute()) {
+    result.assign(SlashDelimited{to_here}.pop_n(2)).append("/").append(target_);
+    LOG(INFO) << "Absolute (relative-to-dag-root) symlink '" << target_
+              << "' leads to '" << result << "' ... ";
+  } else {
+    auto c = to_here.find_last_not_of('/');
+    c = to_here.find_last_of('/', c);
+    DCHECK(c != to_here.size()) << to_here;
       result.assign(to_here, 0, c + 1).append(target_);
       LOG(INFO) << "Relative symlink '" << target_ << "' leads to '" << result
                 << "' ... ";
-    } break;
-    case Style::FromRoot:
-      result.assign(SlashDelimited{to_here}.pop_n(2))
-          .append("/")
-          .append(target_);
-      LOG(INFO) << "Relative-to-root symlink '" << target_ << "' leads to '"
-                << result << "' ... ";
   }
   if (path) {
     result.append("/").append(path.pop_all());
@@ -43,36 +34,10 @@ auto Self::resolve(SlashDelimited path, BlockLookup, std::string& to_here)
   if (result.back() == '/') {
     result.resize(result.size() - 1);
   }
-  LOG(WARNING) << "symlink: '" << to_here << "' -> '" << result << "'.";
+  LOG(INFO) << "symlink: '" << to_here << "' -> '" << result << "'.";
   return PathChange{result};
 }
 
-auto Self::from_target(std::string const& target) -> Style {
-  DCHECK_GT(target.size(), 0U);
-  if (target.at(0) != '/') {
-    return Style::Relative;
-  }
-  SlashDelimited t{target};
-  auto ns = t.pop();
-  if (ns != "ipfs" && ns != "ipns") {
-    return Style::FromRoot;
-  }
-  auto root = t.pop();
-  using namespace libp2p::multi;
-  auto cid = Cid(root);
-  if (!cid.valid()) {
-    if (ns == "ipns") {
-      LOG(WARNING) << "Symlink to DNSLink is highly irregular.";
-      return Style::Absolute;
-    } else {
-      LOG(WARNING) << "Someone has a subdirectory of their DAG root that is "
-                      "called /ipfs/ ? Who does that?";
-      return Style::FromRoot;
-    }
-  }
-  if (cid.codec() == MultiCodec::LIBP2P_KEY) {
-    return ns == "ipns" ? Style::Absolute : Style::FromRoot;
-  } else {
-    return ns == "ipfs" ? Style::Absolute : Style::FromRoot;
-  }
-}
+bool Self::is_absolute() const {
+  return target_.at(0) == '/';
+}
diff --git a/library/src/ipfs_client/ipld/symlink.h b/library/src/ipfs_client/ipld/symlink.h
@@ -5,19 +5,14 @@
 
 namespace ipfs::ipld {
 class Symlink : public DagNode {
-  enum class Style {
-    Relative,
-    Absolute,
-    FromRoot,
-  };
-  Style const style_;
   std::string const target_;
 
-  Style from_target(std::string const&);
   ResolveResult resolve(SlashDelimited path,
                         BlockLookup,
                         std::string& up_to_here) override;
 
+  bool is_absolute() const;
+
  public:
   Symlink(std::string target);
   ~Symlink() noexcept override;

diff --git a/library/src/ipfs_client/ipld/symlink_unittest.cc b/library/src/ipfs_client/ipld/symlink_unittest.cc
@@ -27,23 +27,6 @@ TEST(SymlinkTest, fromBlock) {
       "a/d/e";
   EXPECT_EQ(actual.new_path, expect);
 }
-TEST(SymlinkTest, absolute) {
-  ii::Symlink sub{
-      "/ipfs/bafkreih6wk34z7qlwe2jj4ynowkh4ux6pbqnijcebcz7sd4fz3rnigxa6u"};
-  ii::DagNode& t = sub;
-  auto blu = [](std::string const&) -> ii::NodePtr {
-    throw std::runtime_error{"Block lookup not expected."};
-  };
-  std::string observed_path_to_link{"/ipns/"};
-  observed_path_to_link
-      .append("k51qzi5uqu5dkq4jxcqvujfm2woh4p9y6inrojofxflzdnfht168zf8ynfzuu1")
-      .append("symlinks/absolute_link.txt");
-  auto res = t.resolve(""sv, blu, observed_path_to_link);
-  EXPECT_TRUE(std::holds_alternative<ii::PathChange>(res));
-  EXPECT_EQ(
-      std::get<ii::PathChange>(res).new_path,
-      "/ipfs/bafkreih6wk34z7qlwe2jj4ynowkh4ux6pbqnijcebcz7sd4fz3rnigxa6u");
-}
 TEST(SymlinkTest, rooted) {
   ii::Symlink sub{"/another/path.txt"};
   ii::DagNode& t = sub;
@@ -61,18 +44,3 @@ TEST(SymlinkTest, rooted) {
       "/ipns/k51qzi5uqu5dkq4jxcqvujfm2woh4p9y6inrojofxflzdnfht168zf8ynfzuu1/"
       "another/path.txt");
 }
-TEST(SymlinkTest, ipns_absolute) {
-  ii::Symlink sub{"/ipns/en.wikipedia-on-ipfs.org"};
-  ii::DagNode& t = sub;
-  auto blu = [](std::string const&) -> ii::NodePtr {
-    throw std::runtime_error{"Block lookup not expected."};
-  };
-  std::string observed_path_to_link{"/ipns/"};
-  observed_path_to_link
-      .append("k51qzi5uqu5dkq4jxcqvujfm2woh4p9y6inrojofxflzdnfht168zf8ynfzuu1")
-      .append("symlinks/absolute_link.txt");
-  auto res = t.resolve(""sv, blu, observed_path_to_link);
-  EXPECT_TRUE(std::holds_alternative<ii::PathChange>(res));
-  EXPECT_EQ(std::get<ii::PathChange>(res).new_path,
-            "/ipns/en.wikipedia-on-ipfs.org");
-}