lix/src/libmain/shared.cc
Eelco Dolstra 993fa94fb4 * Move initialisation of variables like nixConfDir from libmain to
libstore so that the Perl bindings can use it as well.  It's vital
  that the Perl bindings use the configuration file, because otherwise
  nix-copy-closure will fail with a ‘database locked’ message if the
  value of ‘use-sqlite-wal’ is changed from the default.
2011-11-22 17:28:41 +00:00

375 lines
11 KiB
C++

#include "config.h"
#include "shared.hh"
#include "globals.hh"
#include "store-api.hh"
#include "util.hh"
#include "misc.hh"
#include <iostream>
#include <cctype>
#include <exception>
#include <sys/stat.h>
#include <unistd.h>
#if HAVE_BOEHMGC
#include <gc/gc.h>
#endif
namespace nix {
volatile sig_atomic_t blockInt = 0;
static void sigintHandler(int signo)
{
if (!blockInt) {
_isInterrupted = 1;
blockInt = 1;
}
}
Path makeRootName(const Path & gcRoot, int & counter)
{
counter++;
if (counter == 1)
return gcRoot;
else
return (format("%1%-%2%") % gcRoot % counter).str();
}
void printGCWarning()
{
static bool haveWarned = false;
warnOnce(haveWarned,
"you did not specify `--add-root'; "
"the result might be removed by the garbage collector");
}
void printMissing(StoreAPI & store, const PathSet & paths)
{
unsigned long long downloadSize, narSize;
PathSet willBuild, willSubstitute, unknown;
queryMissing(store, paths, willBuild, willSubstitute, unknown, downloadSize, narSize);
if (!willBuild.empty()) {
printMsg(lvlInfo, format("these derivations will be built:"));
foreach (PathSet::iterator, i, willBuild)
printMsg(lvlInfo, format(" %1%") % *i);
}
if (!willSubstitute.empty()) {
printMsg(lvlInfo, format("these paths will be downloaded/copied (%.2f MiB download, %.2f MiB unpacked):")
% (downloadSize / (1024.0 * 1024.0))
% (narSize / (1024.0 * 1024.0)));
foreach (PathSet::iterator, i, willSubstitute)
printMsg(lvlInfo, format(" %1%") % *i);
}
if (!unknown.empty()) {
printMsg(lvlInfo, format("don't know how to build these paths%1%:")
% (readOnlyMode ? " (may be caused by read-only store access)" : ""));
foreach (PathSet::iterator, i, unknown)
printMsg(lvlInfo, format(" %1%") % *i);
}
}
static void setLogType(string lt)
{
if (lt == "pretty") logType = ltPretty;
else if (lt == "escapes") logType = ltEscapes;
else if (lt == "flat") logType = ltFlat;
else throw UsageError("unknown log type");
}
static void closeStore()
{
try {
throw;
} catch (std::exception & e) {
printMsg(lvlError,
format("FATAL: unexpected exception (closing store and aborting): %1%") % e.what());
}
try {
store.reset((StoreAPI *) 0);
} catch (...) {
ignoreException();
}
abort();
}
RemoveTempRoots::~RemoveTempRoots()
{
removeTempRoots();
}
static bool showTrace = false;
/* Initialize and reorder arguments, then call the actual argument
processor. */
static void initAndRun(int argc, char * * argv)
{
setDefaultsFromEnvironment();
/* Catch SIGINT. */
struct sigaction act;
act.sa_handler = sigintHandler;
sigfillset(&act.sa_mask);
act.sa_flags = 0;
if (sigaction(SIGINT, &act, 0))
throw SysError("installing handler for SIGINT");
if (sigaction(SIGTERM, &act, 0))
throw SysError("installing handler for SIGTERM");
if (sigaction(SIGHUP, &act, 0))
throw SysError("installing handler for SIGHUP");
/* Ignore SIGPIPE. */
act.sa_handler = SIG_IGN;
act.sa_flags = 0;
if (sigaction(SIGPIPE, &act, 0))
throw SysError("ignoring SIGPIPE");
/* Reset SIGCHLD to its default. */
act.sa_handler = SIG_DFL;
act.sa_flags = 0;
if (sigaction(SIGCHLD, &act, 0))
throw SysError("resetting SIGCHLD");
/* There is no privacy in the Nix system ;-) At least not for
now. In particular, store objects should be readable by
everybody. This prevents nasty surprises when using a shared
store (with the setuid() hack). */
umask(0022);
/* Process the NIX_LOG_TYPE environment variable. */
string lt = getEnv("NIX_LOG_TYPE");
if (lt != "") setLogType(lt);
/* Put the arguments in a vector. */
Strings args, remaining;
while (argc--) args.push_back(*argv++);
args.erase(args.begin());
/* Expand compound dash options (i.e., `-qlf' -> `-q -l -f'), and
ignore options for the ATerm library. */
for (Strings::iterator i = args.begin(); i != args.end(); ++i) {
string arg = *i;
if (arg.length() > 2 && arg[0] == '-' && arg[1] != '-' && !isdigit(arg[1])) {
for (unsigned int j = 1; j < arg.length(); j++)
if (isalpha(arg[j]))
remaining.push_back((string) "-" + arg[j]);
else {
remaining.push_back(string(arg, j));
break;
}
} else remaining.push_back(arg);
}
args = remaining;
remaining.clear();
/* Process default options. */
int verbosityDelta = 0;
for (Strings::iterator i = args.begin(); i != args.end(); ++i) {
string arg = *i;
if (arg == "--verbose" || arg == "-v") verbosityDelta++;
else if (arg == "--quiet") verbosityDelta--;
else if (arg == "--log-type") {
++i;
if (i == args.end()) throw UsageError("`--log-type' requires an argument");
setLogType(*i);
}
else if (arg == "--no-build-output" || arg == "-Q")
buildVerbosity = lvlVomit;
else if (arg == "--print-build-trace")
printBuildTrace = true;
else if (arg == "--help") {
printHelp();
return;
}
else if (arg == "--version") {
std::cout << format("%1% (Nix) %2%") % programId % NIX_VERSION << std::endl;
return;
}
else if (arg == "--keep-failed" || arg == "-K")
keepFailed = true;
else if (arg == "--keep-going" || arg == "-k")
keepGoing = true;
else if (arg == "--fallback")
tryFallback = true;
else if (arg == "--max-jobs" || arg == "-j")
maxBuildJobs = getIntArg<unsigned int>(arg, i, args.end());
else if (arg == "--cores")
buildCores = getIntArg<unsigned int>(arg, i, args.end());
else if (arg == "--readonly-mode")
readOnlyMode = true;
else if (arg == "--max-silent-time")
maxSilentTime = getIntArg<unsigned int>(arg, i, args.end());
else if (arg == "--timeout")
buildTimeout = getIntArg<unsigned int>(arg, i, args.end());
else if (arg == "--no-build-hook")
useBuildHook = false;
else if (arg == "--show-trace")
showTrace = true;
else if (arg == "--option") {
++i; if (i == args.end()) throw UsageError("`--option' requires two arguments");
string name = *i;
++i; if (i == args.end()) throw UsageError("`--option' requires two arguments");
string value = *i;
overrideSetting(name, tokenizeString(value));
}
else remaining.push_back(arg);
}
verbosityDelta += queryIntSetting("verbosity", lvlInfo);
verbosity = (Verbosity) (verbosityDelta < 0 ? 0 : verbosityDelta);
/* Automatically clean up the temporary roots file when we
exit. */
RemoveTempRoots removeTempRoots __attribute__((unused));
/* Make sure that the database gets closed properly, even if
terminate() is called (which happens sometimes due to bugs in
destructor/exceptions interaction, but that needn't preclude a
clean shutdown of the database). */
std::set_terminate(closeStore);
run(remaining);
/* Close the Nix database. */
store.reset((StoreAPI *) 0);
}
bool setuidMode = false;
static void setuidInit()
{
/* Don't do anything if this is not a setuid binary. */
if (getuid() == geteuid() && getgid() == getegid()) return;
uid_t nixUid = geteuid();
gid_t nixGid = getegid();
setuidCleanup();
/* Don't trust the current directory. */
if (chdir("/") == -1) abort();
/* Set the real (and preferably also the save) uid/gid to the
effective uid/gid. This matters mostly when we're not using
build-users (bad!), since some builders (like Perl) complain
when real != effective.
On systems where setresuid is unavailable, we can't drop the
saved uid/gid. This means that we could go back to the
original real uid (i.e., the uid of the caller). That's not
really a problem, except maybe when we execute a builder and
we're not using build-users. In that case, the builder may be
able to switch to the uid of the caller and possibly do bad
stuff. But note that when not using build-users, the builder
could also modify the Nix executables (say, replace them by a
Trojan horse), so the problem is already there. */
#if HAVE_SETRESUID
if (setresuid(nixUid, nixUid, nixUid)) abort();
if (setresgid(nixGid, nixGid, nixGid)) abort();
#elif HAVE_SETREUID
/* Note: doesn't set saved uid/gid! */
fprintf(stderr, "warning: cannot set saved uid\n");
if (setreuid(nixUid, nixUid)) abort();
if (setregid(nixGid, nixGid)) abort();
#else
/* Note: doesn't set real and saved uid/gid! */
fprintf(stderr, "warning: cannot set real and saved uids\n");
if (setuid(nixUid)) abort();
if (setgid(nixGid)) abort();
#endif
setuidMode = true;
}
/* Called when the Boehm GC runs out of memory. */
static void * oomHandler(size_t requested)
{
/* Convert this to a proper C++ exception. */
throw std::bad_alloc();
}
int exitCode = 0;
}
static char buf[1024];
int main(int argc, char * * argv)
{
using namespace nix;
/* If we're setuid, then we need to take some security precautions
right away. */
if (argc == 0) abort();
setuidInit();
/* Turn on buffering for cerr. */
#if HAVE_PUBSETBUF
std::cerr.rdbuf()->pubsetbuf(buf, sizeof(buf));
#endif
std::ios::sync_with_stdio(false);
#if HAVE_BOEHMGC
/* Initialise the Boehm garbage collector. This isn't necessary
on most platforms, but for portability we do it anyway. */
GC_INIT();
GC_oom_fn = oomHandler;
#endif
try {
try {
initAndRun(argc, argv);
} catch (...) {
/* Subtle: we have to make sure that any `interrupted'
condition is discharged before we reach printMsg()
below, since otherwise it will throw an (uncaught)
exception. */
blockInt = 1; /* ignore further SIGINTs */
_isInterrupted = 0;
throw;
}
} catch (UsageError & e) {
printMsg(lvlError,
format(
"error: %1%\n"
"Try `%2% --help' for more information.")
% e.what() % programId);
return 1;
} catch (BaseError & e) {
printMsg(lvlError, format("error: %1%%2%") % (showTrace ? e.prefix() : "") % e.msg());
if (e.prefix() != "" && !showTrace)
printMsg(lvlError, "(use `--show-trace' to show detailed location information)");
return e.status;
} catch (std::exception & e) {
printMsg(lvlError, format("error: %1%") % e.what());
return 1;
}
return exitCode;
}