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-rw-r--r--nix/libutil/hash.cc101
-rw-r--r--nix/libutil/util.cc62
-rw-r--r--nix/libutil/util.hh6
3 files changed, 75 insertions, 94 deletions
diff --git a/nix/libutil/hash.cc b/nix/libutil/hash.cc
index 050446610f..2da00a53de 100644
--- a/nix/libutil/hash.cc
+++ b/nix/libutil/hash.cc
@@ -84,7 +84,7 @@ string printHash(const Hash & hash)
     return string(buf, hash.hashSize * 2);
 }
 
-    
+
 Hash parseHash(HashType ht, const string & s)
 {
     Hash hash(ht);
@@ -92,7 +92,7 @@ Hash parseHash(HashType ht, const string & s)
         throw Error(format("invalid hash `%1%'") % s);
     for (unsigned int i = 0; i < hash.hashSize; i++) {
         string s2(s, i * 2, 2);
-        if (!isxdigit(s2[0]) || !isxdigit(s2[1])) 
+        if (!isxdigit(s2[0]) || !isxdigit(s2[1]))
             throw Error(format("invalid hash `%1%'") % s);
         std::istringstream str(s2);
         int n;
@@ -103,24 +103,6 @@ Hash parseHash(HashType ht, const string & s)
 }
 
 
-static unsigned char divMod(unsigned char * bytes, unsigned char y)
-{
-    unsigned int borrow = 0;
-
-    int pos = Hash::maxHashSize - 1;
-    while (pos >= 0 && !bytes[pos]) --pos;
-
-    for ( ; pos >= 0; --pos) {
-        unsigned int s = bytes[pos] + (borrow << 8);
-        unsigned int d = s / y;
-        borrow = s % y;
-        bytes[pos] = d;
-    }
-
-    return borrow;
-}
-
-
 unsigned int hashLength32(const Hash & hash)
 {
     return (hash.hashSize * 8 - 1) / 5 + 1;
@@ -136,19 +118,19 @@ string printHash32(const Hash & hash)
     Hash hash2(hash);
     unsigned int len = hashLength32(hash);
 
-    const char * chars = base32Chars.data();
-    
-    string s(len, '0');
-
-    int pos = len - 1;
-    while (pos >= 0) {
-        unsigned char digit = divMod(hash2.hash, 32);
-        s[pos--] = chars[digit];
+    string s;
+    s.reserve(len);
+
+    for (int n = len - 1; n >= 0; n--) {
+        unsigned int b = n * 5;
+        unsigned int i = b / 8;
+        unsigned int j = b % 8;
+        unsigned char c =
+            (hash.hash[i] >> j)
+            | (i >= hash.hashSize - 1 ? 0 : hash.hash[i + 1] << (8 - j));
+        s.push_back(base32Chars[c & 0x1f]);
     }
 
-    for (unsigned int i = 0; i < hash2.maxHashSize; ++i)
-        assert(hash2.hash[i] == 0);
-
     return s;
 }
 
@@ -159,51 +141,24 @@ string printHash16or32(const Hash & hash)
 }
 
 
-static bool mul(unsigned char * bytes, unsigned char y, int maxSize)
-{
-    unsigned char carry = 0;
-
-    for (int pos = 0; pos < maxSize; ++pos) {
-        unsigned int m = bytes[pos] * y + carry;
-        bytes[pos] = m & 0xff;
-        carry = m >> 8;
-    }
-
-    return carry;
-}
-
-
-static bool add(unsigned char * bytes, unsigned char y, int maxSize)
-{
-    unsigned char carry = y;
-
-    for (int pos = 0; pos < maxSize; ++pos) {
-        unsigned int m = bytes[pos] + carry;
-        bytes[pos] = m & 0xff;
-        carry = m >> 8;
-        if (carry == 0) break;
-    }
-
-    return carry;
-}
-
-
 Hash parseHash32(HashType ht, const string & s)
 {
     Hash hash(ht);
+    unsigned int len = hashLength32(ht);
+    assert(s.size() == len);
 
-    const char * chars = base32Chars.data();
-
-    for (unsigned int i = 0; i < s.length(); ++i) {
-        char c = s[i];
+    for (unsigned int n = 0; n < len; ++n) {
+        char c = s[len - n - 1];
         unsigned char digit;
         for (digit = 0; digit < base32Chars.size(); ++digit) /* !!! slow */
-            if (chars[digit] == c) break;
+            if (base32Chars[digit] == c) break;
         if (digit >= 32)
-            throw Error(format("invalid base-32 hash `%1%'") % s);
-        if (mul(hash.hash, 32, hash.hashSize) ||
-            add(hash.hash, digit, hash.hashSize))
-            throw Error(format("base-32 hash `%1%' is too large") % s);
+            throw Error(format("invalid base-32 hash '%1%'") % s);
+        unsigned int b = n * 5;
+        unsigned int i = b / 8;
+        unsigned int j = b % 8;
+        hash.hash[i] |= digit << j;
+        if (i < hash.hashSize - 1) hash.hash[i + 1] |= digit >> (8 - j);
     }
 
     return hash;
@@ -299,7 +254,7 @@ Hash hashFile(HashType ht, const Path & path)
         if (n == -1) throw SysError(format("reading file `%1%'") % path);
         update(ht, ctx, buf, n);
     }
-    
+
     finish(ht, ctx, hash.hash);
     return hash;
 }
@@ -311,7 +266,7 @@ HashSink::HashSink(HashType ht) : ht(ht)
     bytes = 0;
     start(ht, *ctx);
 }
-    
+
 HashSink::~HashSink()
 {
     bufPos = 0;
@@ -369,7 +324,7 @@ HashType parseHashType(const string & s)
     else return htUnknown;
 }
 
- 
+
 string printHashType(HashType ht)
 {
     if (ht == htMD5) return "md5";
@@ -378,5 +333,5 @@ string printHashType(HashType ht)
     else throw Error("cannot print unknown hash type");
 }
 
- 
+
 }
diff --git a/nix/libutil/util.cc b/nix/libutil/util.cc
index a4a1ddb12a..dab4235b04 100644
--- a/nix/libutil/util.cc
+++ b/nix/libutil/util.cc
@@ -19,6 +19,10 @@
 #include <sys/syscall.h>
 #endif
 
+#ifdef __linux__
+#include <sys/prctl.h>
+#endif
+
 
 extern char * * environ;
 
@@ -189,8 +193,12 @@ Path readLink(const Path & path)
     if (!S_ISLNK(st.st_mode))
         throw Error(format("`%1%' is not a symlink") % path);
     char buf[st.st_size];
-    if (readlink(path.c_str(), buf, st.st_size) != st.st_size)
-        throw SysError(format("reading symbolic link `%1%'") % path);
+    ssize_t rlsize = readlink(path.c_str(), buf, st.st_size);
+    if (rlsize == -1)
+        throw SysError(format("reading symbolic link '%1%'") % path);
+    else if (rlsize > st.st_size)
+        throw Error(format("symbolic link ‘%1%’ size overflow %2% > %3%")
+            % path % rlsize % st.st_size);
     return string(buf, st.st_size);
 }
 
@@ -260,8 +268,8 @@ void writeFile(const Path & path, const string & s)
 {
     AutoCloseFD fd = open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT, 0666);
     if (fd == -1)
-        throw SysError(format("opening file `%1%'") % path);
-    writeFull(fd, (unsigned char *) s.data(), s.size());
+        throw SysError(format("opening file '%1%'") % path);
+    writeFull(fd, s);
 }
 
 
@@ -288,7 +296,7 @@ string readLine(int fd)
 void writeLine(int fd, string s)
 {
     s += '\n';
-    writeFull(fd, (const unsigned char *) s.data(), s.size());
+    writeFull(fd, s);
 }
 
 
@@ -478,18 +486,13 @@ void warnOnce(bool & haveWarned, const FormatOrString & fs)
 }
 
 
-static void defaultWriteToStderr(const unsigned char * buf, size_t count)
-{
-    writeFull(STDERR_FILENO, buf, count);
-}
-
-
 void writeToStderr(const string & s)
 {
     try {
-        auto p = _writeToStderr;
-        if (!p) p = defaultWriteToStderr;
-        p((const unsigned char *) s.data(), s.size());
+        if (_writeToStderr)
+            _writeToStderr((const unsigned char *) s.data(), s.size());
+        else
+            writeFull(STDERR_FILENO, s);
     } catch (SysError & e) {
         /* Ignore failing writes to stderr if we're in an exception
            handler, otherwise throw an exception.  We need to ignore
@@ -501,7 +504,7 @@ void writeToStderr(const string & s)
 }
 
 
-void (*_writeToStderr) (const unsigned char * buf, size_t count) = defaultWriteToStderr;
+void (*_writeToStderr) (const unsigned char * buf, size_t count) = 0;
 
 
 void readFull(int fd, unsigned char * buf, size_t count)
@@ -535,6 +538,12 @@ void writeFull(int fd, const unsigned char * buf, size_t count)
 }
 
 
+void writeFull(int fd, const string & s)
+{
+    writeFull(fd, (const unsigned char *) s.data(), s.size());
+}
+
+
 string drainFD(int fd)
 {
     string result;
@@ -867,6 +876,10 @@ pid_t startProcess(std::function<void()> fun,
     if (pid == 0) {
         _writeToStderr = 0;
         try {
+#if __linux__
+            if (dieWithParent && prctl(PR_SET_PDEATHSIG, SIGKILL) == -1)
+                throw SysError("setting death signal");
+#endif
             restoreAffinity();
             fun();
         } catch (std::exception & e) {
@@ -884,16 +897,19 @@ pid_t startProcess(std::function<void()> fun,
 }
 
 
+std::vector<const char *> stringsToCharPtrs(const Strings & ss)
+{
+    std::vector<const char *> res;
+    for (auto & s : ss) res.push_back(s.c_str());
+    res.push_back(0);
+    return res;
+}
+
+
 string runProgram(Path program, bool searchPath, const Strings & args)
 {
     checkInterrupt();
 
-    std::vector<const char *> cargs; /* careful with c_str()! */
-    cargs.push_back(program.c_str());
-    for (Strings::const_iterator i = args.begin(); i != args.end(); ++i)
-        cargs.push_back(i->c_str());
-    cargs.push_back(0);
-
     /* Create a pipe. */
     Pipe pipe;
     pipe.create();
@@ -903,6 +919,10 @@ string runProgram(Path program, bool searchPath, const Strings & args)
         if (dup2(pipe.writeSide, STDOUT_FILENO) == -1)
             throw SysError("dupping stdout");
 
+        Strings args_(args);
+        args_.push_front(program);
+        auto cargs = stringsToCharPtrs(args_);
+
         if (searchPath)
             execvp(program.c_str(), (char * *) &cargs[0]);
         else
diff --git a/nix/libutil/util.hh b/nix/libutil/util.hh
index 0ad0026711..6a84ed8851 100644
--- a/nix/libutil/util.hh
+++ b/nix/libutil/util.hh
@@ -171,6 +171,7 @@ extern void (*_writeToStderr) (const unsigned char * buf, size_t count);
    requested number of bytes. */
 void readFull(int fd, unsigned char * buf, size_t count);
 void writeFull(int fd, const unsigned char * buf, size_t count);
+void writeFull(int fd, const string & s);
 
 MakeError(EndOfFile, Error)
 
@@ -280,6 +281,11 @@ string runProgram(Path program, bool searchPath = false,
 
 MakeError(ExecError, Error)
 
+/* Convert a list of strings to a null-terminated vector of char
+   *'s. The result must not be accessed beyond the lifetime of the
+   list of strings. */
+std::vector<const char *> stringsToCharPtrs(const Strings & ss);
+
 /* Close all file descriptors except stdin, stdout, stderr, and those
    listed in the given set.  Good practice in child processes. */
 void closeMostFDs(const set<int> & exceptions);
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-11-11 03:54:32 +0000