Merge pull request #5335 from edolstra/socket-paths

Support arbitrary-length socket paths
This commit is contained in:
Eelco Dolstra 2021-10-05 17:36:07 +02:00 committed by GitHub
commit fd57e7074f
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5 changed files with 81 additions and 32 deletions

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@ -126,8 +126,7 @@
'' ''
mkdir -p $out/nix-support mkdir -p $out/nix-support
# Converts /nix/store/50p3qk8kka9dl6wyq40vydq945k0j3kv-nix-2.4pre20201102_550e11f/bin/nix # Converts /nix/store/50p3qk8k...-nix-2.4pre20201102_550e11f/bin/nix to 50p3qk8k.../bin/nix.
# To 50p3qk8kka9dl6wyq40vydq945k0j3kv/bin/nix
tarballPath() { tarballPath() {
# Remove the store prefix # Remove the store prefix
local path=''${1#${builtins.storeDir}/} local path=''${1#${builtins.storeDir}/}
@ -153,13 +152,15 @@
echo "file installer $out/install" >> $out/nix-support/hydra-build-products echo "file installer $out/install" >> $out/nix-support/hydra-build-products
''; '';
testNixVersions = pkgs: client: daemon: with commonDeps pkgs; pkgs.stdenv.mkDerivation { testNixVersions = pkgs: client: daemon: with commonDeps pkgs; with pkgs.lib; pkgs.stdenv.mkDerivation {
NIX_DAEMON_PACKAGE = daemon; NIX_DAEMON_PACKAGE = daemon;
NIX_CLIENT_PACKAGE = client; NIX_CLIENT_PACKAGE = client;
# Must keep this name short as OSX has a rather strict limit on the name =
# socket path length, and this name appears in the path of the "nix-tests"
# nix-daemon socket used in the tests + optionalString
name = "nix-tests"; (versionAtLeast daemon.version "2.4pre20211005" &&
versionAtLeast client.version "2.4pre20211005")
"-${client.version}-against-${daemon.version}";
inherit version; inherit version;
src = self; src = self;

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@ -65,16 +65,7 @@ ref<RemoteStore::Connection> UDSRemoteStore::openConnection()
throw SysError("cannot create Unix domain socket"); throw SysError("cannot create Unix domain socket");
closeOnExec(conn->fd.get()); closeOnExec(conn->fd.get());
string socketPath = path ? *path : settings.nixDaemonSocketFile; nix::connect(conn->fd.get(), path ? *path : settings.nixDaemonSocketFile);
struct sockaddr_un addr;
addr.sun_family = AF_UNIX;
if (socketPath.size() + 1 >= sizeof(addr.sun_path))
throw Error("socket path '%1%' is too long", socketPath);
strcpy(addr.sun_path, socketPath.c_str());
if (::connect(conn->fd.get(), (struct sockaddr *) &addr, sizeof(addr)) == -1)
throw SysError("cannot connect to daemon at '%1%'", socketPath);
conn->from.fd = conn->fd.get(); conn->from.fd = conn->fd.get();
conn->to.fd = conn->fd.get(); conn->to.fd = conn->fd.get();

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@ -903,7 +903,7 @@ int Pid::wait()
return status; return status;
} }
if (errno != EINTR) if (errno != EINTR)
throw SysError("cannot get child exit status"); throw SysError("cannot get exit status of PID %d", pid);
checkInterrupt(); checkInterrupt();
} }
} }
@ -1686,16 +1686,7 @@ AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode)
closeOnExec(fdSocket.get()); closeOnExec(fdSocket.get());
struct sockaddr_un addr; bind(fdSocket.get(), path);
addr.sun_family = AF_UNIX;
if (path.size() + 1 >= sizeof(addr.sun_path))
throw Error("socket path '%1%' is too long", path);
strcpy(addr.sun_path, path.c_str());
unlink(path.c_str());
if (bind(fdSocket.get(), (struct sockaddr *) &addr, sizeof(addr)) == -1)
throw SysError("cannot bind to socket '%1%'", path);
if (chmod(path.c_str(), mode) == -1) if (chmod(path.c_str(), mode) == -1)
throw SysError("changing permissions on '%1%'", path); throw SysError("changing permissions on '%1%'", path);
@ -1707,6 +1698,66 @@ AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode)
} }
void bind(int fd, const std::string & path)
{
unlink(path.c_str());
struct sockaddr_un addr;
addr.sun_family = AF_UNIX;
if (path.size() + 1 >= sizeof(addr.sun_path)) {
Pid pid = startProcess([&]() {
auto dir = dirOf(path);
if (chdir(dir.c_str()) == -1)
throw SysError("chdir to '%s' failed", dir);
std::string base(baseNameOf(path));
if (base.size() + 1 >= sizeof(addr.sun_path))
throw Error("socket path '%s' is too long", base);
strcpy(addr.sun_path, base.c_str());
if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1)
throw SysError("cannot bind to socket '%s'", path);
_exit(0);
});
int status = pid.wait();
if (status != 0)
throw Error("cannot bind to socket '%s'", path);
} else {
strcpy(addr.sun_path, path.c_str());
if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1)
throw SysError("cannot bind to socket '%s'", path);
}
}
void connect(int fd, const std::string & path)
{
struct sockaddr_un addr;
addr.sun_family = AF_UNIX;
if (path.size() + 1 >= sizeof(addr.sun_path)) {
Pid pid = startProcess([&]() {
auto dir = dirOf(path);
if (chdir(dir.c_str()) == -1)
throw SysError("chdir to '%s' failed", dir);
std::string base(baseNameOf(path));
if (base.size() + 1 >= sizeof(addr.sun_path))
throw Error("socket path '%s' is too long", base);
strcpy(addr.sun_path, base.c_str());
if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1)
throw SysError("cannot connect to socket at '%s'", path);
_exit(0);
});
int status = pid.wait();
if (status != 0)
throw Error("cannot connect to socket at '%s'", path);
} else {
strcpy(addr.sun_path, path.c_str());
if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1)
throw SysError("cannot connect to socket at '%s'", path);
}
}
string showBytes(uint64_t bytes) string showBytes(uint64_t bytes)
{ {
return fmt("%.2f MiB", bytes / (1024.0 * 1024.0)); return fmt("%.2f MiB", bytes / (1024.0 * 1024.0));

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@ -259,7 +259,7 @@ void killUser(uid_t uid);
pid to the caller. */ pid to the caller. */
struct ProcessOptions struct ProcessOptions
{ {
string errorPrefix = "error: "; string errorPrefix = "";
bool dieWithParent = true; bool dieWithParent = true;
bool runExitHandlers = false; bool runExitHandlers = false;
bool allowVfork = true; bool allowVfork = true;
@ -574,6 +574,12 @@ void commonChildInit(Pipe & logPipe);
/* Create a Unix domain socket in listen mode. */ /* Create a Unix domain socket in listen mode. */
AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode); AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode);
/* Bind a Unix domain socket to a path. */
void bind(int fd, const std::string & path);
/* Connect to a Unix domain socket. */
void connect(int fd, const std::string & path);
// A Rust/Python-like enumerate() iterator adapter. // A Rust/Python-like enumerate() iterator adapter.
// Borrowed from http://reedbeta.com/blog/python-like-enumerate-in-cpp17. // Borrowed from http://reedbeta.com/blog/python-like-enumerate-in-cpp17.

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@ -156,9 +156,6 @@ static void daemonLoop()
if (chdir("/") == -1) if (chdir("/") == -1)
throw SysError("cannot change current directory"); throw SysError("cannot change current directory");
// Get rid of children automatically; don't let them become zombies.
setSigChldAction(true);
AutoCloseFD fdSocket; AutoCloseFD fdSocket;
// Handle socket-based activation by systemd. // Handle socket-based activation by systemd.
@ -176,6 +173,9 @@ static void daemonLoop()
fdSocket = createUnixDomainSocket(settings.nixDaemonSocketFile, 0666); fdSocket = createUnixDomainSocket(settings.nixDaemonSocketFile, 0666);
} }
// Get rid of children automatically; don't let them become zombies.
setSigChldAction(true);
// Loop accepting connections. // Loop accepting connections.
while (1) { while (1) {