nix-super/src/libstore/nar-info.cc
Michal Sojka d30d2dc861 Make "NAR info file is corrupt" messages more informative
Recently, I encountered the "NAR info file 'xxxx' is corrupt" error
with my binary cache. The message is not helpful in determining, which
kind of corruption happened. The file, fetched with curl, looked
reasonably.

This commit adds more information to the error message, which should
allow debugging and hopefully fixing the problem.
2023-04-18 14:10:49 +02:00

128 lines
3.9 KiB
C++

#include "globals.hh"
#include "nar-info.hh"
#include "store-api.hh"
namespace nix {
NarInfo::NarInfo(const Store & store, const std::string & s, const std::string & whence)
: ValidPathInfo(StorePath(StorePath::dummy), Hash(Hash::dummy)) // FIXME: hack
{
unsigned line = 1;
auto corrupt = [&](const char * reason) {
return Error("NAR info file '%1%' is corrupt: %2%", whence,
std::string(reason) + (line > 0 ? " at line " + std::to_string(line) : ""));
};
auto parseHashField = [&](const std::string & s) {
try {
return Hash::parseAnyPrefixed(s);
} catch (BadHash &) {
throw corrupt("bad hash");
}
};
bool havePath = false;
bool haveNarHash = false;
size_t pos = 0;
while (pos < s.size()) {
size_t colon = s.find(':', pos);
if (colon == std::string::npos) throw corrupt("expecting ':'");
std::string name(s, pos, colon - pos);
size_t eol = s.find('\n', colon + 2);
if (eol == std::string::npos) throw corrupt("expecting '\\n'");
std::string value(s, colon + 2, eol - colon - 2);
if (name == "StorePath") {
path = store.parseStorePath(value);
havePath = true;
}
else if (name == "URL")
url = value;
else if (name == "Compression")
compression = value;
else if (name == "FileHash")
fileHash = parseHashField(value);
else if (name == "FileSize") {
auto n = string2Int<decltype(fileSize)>(value);
if (!n) throw corrupt("invalid FileSize");
fileSize = *n;
}
else if (name == "NarHash") {
narHash = parseHashField(value);
haveNarHash = true;
}
else if (name == "NarSize") {
auto n = string2Int<decltype(narSize)>(value);
if (!n) throw corrupt("invalid NarSize");
narSize = *n;
}
else if (name == "References") {
auto refs = tokenizeString<Strings>(value, " ");
if (!references.empty()) throw corrupt("extra References");
for (auto & r : refs)
references.insert(StorePath(r));
}
else if (name == "Deriver") {
if (value != "unknown-deriver")
deriver = StorePath(value);
}
else if (name == "Sig")
sigs.insert(value);
else if (name == "CA") {
if (ca) throw corrupt("extra CA");
// FIXME: allow blank ca or require skipping field?
ca = ContentAddress::parseOpt(value);
}
pos = eol + 1;
line += 1;
}
if (compression == "") compression = "bzip2";
if (!havePath || !haveNarHash || url.empty() || narSize == 0) {
line = 0; // don't include line information in the error
throw corrupt(
!havePath ? "StorePath missing" :
!haveNarHash ? "NarHash missing" :
url.empty() ? "URL missing" :
narSize == 0 ? "NarSize missing or zero"
: "?");
}
}
std::string NarInfo::to_string(const Store & store) const
{
std::string res;
res += "StorePath: " + store.printStorePath(path) + "\n";
res += "URL: " + url + "\n";
assert(compression != "");
res += "Compression: " + compression + "\n";
assert(fileHash && fileHash->type == htSHA256);
res += "FileHash: " + fileHash->to_string(Base32, true) + "\n";
res += "FileSize: " + std::to_string(fileSize) + "\n";
assert(narHash.type == htSHA256);
res += "NarHash: " + narHash.to_string(Base32, true) + "\n";
res += "NarSize: " + std::to_string(narSize) + "\n";
res += "References: " + concatStringsSep(" ", shortRefs()) + "\n";
if (deriver)
res += "Deriver: " + std::string(deriver->to_string()) + "\n";
for (auto sig : sigs)
res += "Sig: " + sig + "\n";
if (ca)
res += "CA: " + renderContentAddress(*ca) + "\n";
return res;
}
}