* [bug#27426] [PATCH 2/2] daemon: '--listen' can be passed several times, can specify TCP endpoints.
2017-06-19 16:04 ` [bug#27426] [PATCH 1/2] store: Define a default port for TCP connections Ludovic Courtès
@ 2017-06-19 16:04 ` Ludovic Courtès
0 siblings, 0 replies; 8+ messages in thread
From: Ludovic Courtès @ 2017-06-19 16:04 UTC (permalink / raw)
To: 27426; +Cc: Ludovic Courtès
From: Ludovic Courtès <ludovic.courtes@inria.fr>
* nix/nix-daemon/guix-daemon.cc (DEFAULT_GUIX_PORT): New macro.
(listen_options): New variable.
(parse_opt): Push back '--listen' options to LISTEN_OPTIONS.
(open_unix_domain_socket, open_inet_socket)
(listening_sockets): New functions.
(main): Use it. Pass SOCKETS to 'run'.
* nix/nix-daemon/nix-daemon.cc (matchUser): Remove.
(SD_LISTEN_FDS_START): Remove.
(acceptConnection): New function.
(daemonLoop): Rewrite to take a vector of file descriptors, to select(2)
on them, and to call 'acceptConnection'.
(run): Change to take a vector of file descriptors.
* tests/guix-daemon.sh: Add test.
---
doc/guix.texi | 39 +++++-
nix/nix-daemon/guix-daemon.cc | 152 +++++++++++++++++++++--
nix/nix-daemon/nix-daemon.cc | 283 +++++++++++++++++++-----------------------
tests/guix-daemon.sh | 12 ++
4 files changed, 311 insertions(+), 175 deletions(-)
diff --git a/doc/guix.texi b/doc/guix.texi
index 4933a98dd..ca265fc49 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -1258,12 +1258,35 @@ Assume @var{system} as the current system type. By default it is the
architecture/kernel pair found at configure time, such as
@code{x86_64-linux}.
-@item --listen=@var{socket}
-Listen for connections on @var{socket}, the file name of a Unix-domain
-socket. The default socket is
-@file{@var{localstatedir}/daemon-socket/socket}. This option is only
-useful in exceptional circumstances, such as if you need to run several
-daemons on the same machine.
+@item --listen=@var{endpoint}
+Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
+as the file name of a Unix-domain socket if it starts with
+@code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
+host name or host name and port to listen to. Here are a few example:
+
+@table @code
+@item --listen=/gnu/var/daemon
+Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
+creating it if needed.
+
+@item --listen=localhost
+Listen for TCP connections on the network interface corresponding to
+@code{localhost}, on port 44146.
+
+@item --listen=128.0.0.42:1234
+Listen for TCP connections on the network interface corresponding to
+@code{128.0.0.42}, on port 1234.
+@end table
+
+This option can be repeated multiple times, in which case
+@command{guix-daemon} accepts connections on all the specified
+endpoints. Users can tell client commands what endpoint to connect to
+by setting the @code{GUIX_DAEMON_SOCKET} environment variable
+(@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
+
+When @code{--listen} is omitted, @command{guix-daemon} listens for
+connections on the Unix-domain socket located at
+@file{@var{localstatedir}/daemon-socket/socket}.
@end table
@@ -3781,6 +3804,10 @@ This setup is suitable on local networks, such as clusters, where only
trusted nodes may connect to the build daemon at
@code{master.guix.example.org}.
+The @code{--listen} option of @command{guix-daemon} can be used to
+instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
+@code{--listen}}).
+
@item ssh
@cindex SSH access to build daemons
These URIs allow you to connect to a remote daemon over
diff --git a/nix/nix-daemon/guix-daemon.cc b/nix/nix-daemon/guix-daemon.cc
index 0d9c33d1d..ba898f572 100644
--- a/nix/nix-daemon/guix-daemon.cc
+++ b/nix/nix-daemon/guix-daemon.cc
@@ -1,5 +1,6 @@
/* GNU Guix --- Functional package management for GNU
Copyright (C) 2012, 2013, 2014, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org>
+ Copyright (C) 2006, 2010, 2012, 2014 Eelco Dolstra <e.dolstra@tudelft.nl>
This file is part of GNU Guix.
@@ -30,8 +31,12 @@
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <netdb.h>
#include <strings.h>
#include <exception>
+#include <iostream>
#include <libintl.h>
#include <locale.h>
@@ -43,7 +48,7 @@ char **argvSaved;
using namespace nix;
/* Entry point in `nix-daemon.cc'. */
-extern void run (Strings args);
+extern void run (const std::vector<int> &);
\f
/* Command-line options. */
@@ -149,6 +154,12 @@ to live outputs") },
};
+/* Default port for '--listen' on TCP/IP. */
+#define DEFAULT_GUIX_PORT "44146"
+
+/* List of '--listen' options. */
+static std::list<std::string> listen_options;
+
/* Convert ARG to a Boolean value, or throw an error if it does not denote a
Boolean. */
static bool
@@ -217,15 +228,7 @@ parse_opt (int key, char *arg, struct argp_state *state)
settings.keepLog = false;
break;
case GUIX_OPT_LISTEN:
- try
- {
- settings.nixDaemonSocketFile = canonPath (arg);
- }
- catch (std::exception &e)
- {
- fprintf (stderr, _("error: %s\n"), e.what ());
- exit (EXIT_FAILURE);
- }
+ listen_options.push_back (arg);
break;
case GUIX_OPT_SUBSTITUTE_URLS:
settings.set ("substitute-urls", arg);
@@ -276,13 +279,134 @@ static const struct argp argp =
guix_textdomain
};
+\f
+static int
+open_unix_domain_socket (const char *file)
+{
+ /* Create and bind to a Unix domain socket. */
+ AutoCloseFD fdSocket = socket (PF_UNIX, SOCK_STREAM, 0);
+ if (fdSocket == -1)
+ throw SysError ("cannot create Unix domain socket");
+
+ createDirs (dirOf (file));
+
+ /* Urgh, sockaddr_un allows path names of only 108 characters.
+ So chdir to the socket directory so that we can pass a
+ relative path name. */
+ if (chdir (dirOf (file).c_str ()) == -1)
+ throw SysError ("cannot change current directory");
+ Path fileRel = "./" + baseNameOf (file);
+
+ struct sockaddr_un addr;
+ addr.sun_family = AF_UNIX;
+ if (fileRel.size () >= sizeof (addr.sun_path))
+ throw Error (format ("socket path `%1%' is too long") % fileRel);
+ strcpy (addr.sun_path, fileRel.c_str ());
+
+ unlink (file);
+
+ /* Make sure that the socket is created with 0666 permission
+ (everybody can connect --- provided they have access to the
+ directory containing the socket). */
+ mode_t oldMode = umask (0111);
+ int res = bind (fdSocket, (struct sockaddr *) &addr, sizeof addr);
+ umask (oldMode);
+ if (res == -1)
+ throw SysError (format ("cannot bind to socket `%1%'") % file);
+
+ if (chdir ("/") == -1) /* back to the root */
+ throw SysError ("cannot change current directory");
+
+ if (listen (fdSocket, 5) == -1)
+ throw SysError (format ("cannot listen on socket `%1%'") % file);
+
+ return fdSocket.borrow ();
+}
+
+/* Return a listening socket for ADDRESS, which has the given LENGTH. */
+static int
+open_inet_socket (const struct sockaddr *address, socklen_t length)
+{
+ AutoCloseFD fd = socket (address->sa_family, SOCK_STREAM, 0);
+ if (fd == -1)
+ throw SysError("cannot open inet socket");
+
+ int res = bind (fd, address, length);
+ if (res == -1)
+ throw SysError("cannot bind inet socket");
+
+ if (listen (fd, 5) == -1)
+ throw SysError (format ("cannot listen on inet socket"));
+
+ return fd.borrow ();
+}
+
+/* Return a list of file descriptors of listening sockets. */
+static std::vector<int>
+listening_sockets (const std::list<std::string> &options)
+{
+ std::vector<int> result;
+
+ if (options.empty ())
+ {
+ /* Open the default Unix-domain socket. */
+ auto fd = open_unix_domain_socket (settings.nixDaemonSocketFile.c_str ());
+ result.push_back (fd);
+ return result;
+ }
+
+ /* Open the user-specified sockets. */
+ for (const std::string& option: options)
+ {
+ if (option[0] == '/')
+ {
+ /* Assume OPTION is the file name of a Unix-domain socket. */
+ settings.nixDaemonSocketFile = canonPath (option);
+ int fd =
+ open_unix_domain_socket (settings.nixDaemonSocketFile.c_str ());
+ result.push_back (fd);
+ }
+ else
+ {
+ /* Assume OPTIONS has the form "HOST" or "HOST:PORT". */
+ auto colon = option.find_last_of (":");
+ auto host = colon == std::string::npos
+ ? option : option.substr (0, colon);
+ auto port = colon == std::string::npos
+ ? DEFAULT_GUIX_PORT
+ : option.substr (colon + 1, option.size () - colon - 1);
+
+ struct addrinfo *res, hints;
+
+ memset (&hints, '\0', sizeof hints);
+ hints.ai_socktype = SOCK_STREAM;
+ hints.ai_flags = AI_NUMERICSERV | AI_ADDRCONFIG;
+
+ int err = getaddrinfo (host.c_str(), port.c_str (),
+ &hints, &res);
+
+ if (err != 0)
+ throw Error(format ("failed to look up '%1%': %2%")
+ % option % gai_strerror (err));
+
+ printMsg (lvlDebug, format ("listening on '%1%', port '%2%'")
+ % host % port);
+
+ /* XXX: Pick the first result, RES. */
+ result.push_back (open_inet_socket (res->ai_addr,
+ res->ai_addrlen));
+
+ freeaddrinfo (res);
+ }
+ }
+
+ return result;
+}
\f
int
main (int argc, char *argv[])
{
- static const Strings nothing;
-
setlocale (LC_ALL, "");
bindtextdomain (guix_textdomain, LOCALEDIR);
textdomain (guix_textdomain);
@@ -359,6 +483,8 @@ main (int argc, char *argv[])
argp_parse (&argp, argc, argv, 0, 0, 0);
+ auto sockets = listening_sockets (listen_options);
+
/* Effect all the changes made via 'settings.set'. */
settings.update ();
@@ -402,7 +528,7 @@ using `--build-users-group' is highly recommended\n"));
printMsg (lvlDebug,
format ("listening on `%1%'") % settings.nixDaemonSocketFile);
- run (nothing);
+ run (sockets);
}
catch (std::exception &e)
{
diff --git a/nix/nix-daemon/nix-daemon.cc b/nix/nix-daemon/nix-daemon.cc
index 79580ffb4..3d8e90990 100644
--- a/nix/nix-daemon/nix-daemon.cc
+++ b/nix/nix-daemon/nix-daemon.cc
@@ -18,6 +18,7 @@
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>
+#include <arpa/inet.h>
#include <fcntl.h>
#include <errno.h>
#include <pwd.h>
@@ -809,151 +810,87 @@ static void setSigChldAction(bool autoReap)
}
-bool matchUser(const string & user, const string & group, const Strings & users)
+/* Accept a connection on FDSOCKET and fork a server process to process the
+ new connection. */
+static void acceptConnection(int fdSocket)
{
- if (find(users.begin(), users.end(), "*") != users.end())
- return true;
-
- if (find(users.begin(), users.end(), user) != users.end())
- return true;
-
- for (auto & i : users)
- if (string(i, 0, 1) == "@") {
- if (group == string(i, 1)) return true;
- struct group * gr = getgrnam(i.c_str() + 1);
- if (!gr) continue;
- for (char * * mem = gr->gr_mem; *mem; mem++)
- if (user == string(*mem)) return true;
- }
-
- return false;
-}
-
-
-#define SD_LISTEN_FDS_START 3
-
-
-static void daemonLoop()
-{
- if (chdir("/") == -1)
- throw SysError("cannot change current directory");
-
- /* Get rid of children automatically; don't let them become
- zombies. */
- setSigChldAction(true);
-
- AutoCloseFD fdSocket;
-
- /* Handle socket-based activation by systemd. */
- if (getEnv("LISTEN_FDS") != "") {
- if (getEnv("LISTEN_PID") != std::to_string(getpid()) || getEnv("LISTEN_FDS") != "1")
- throw Error("unexpected systemd environment variables");
- fdSocket = SD_LISTEN_FDS_START;
- }
-
- /* Otherwise, create and bind to a Unix domain socket. */
- else {
-
- /* Create and bind to a Unix domain socket. */
- fdSocket = socket(PF_UNIX, SOCK_STREAM, 0);
- if (fdSocket == -1)
- throw SysError("cannot create Unix domain socket");
-
- string socketPath = settings.nixDaemonSocketFile;
-
- createDirs(dirOf(socketPath));
-
- /* Urgh, sockaddr_un allows path names of only 108 characters.
- So chdir to the socket directory so that we can pass a
- relative path name. */
- if (chdir(dirOf(socketPath).c_str()) == -1)
- throw SysError("cannot change current directory");
- Path socketPathRel = "./" + baseNameOf(socketPath);
-
- struct sockaddr_un addr;
- addr.sun_family = AF_UNIX;
- if (socketPathRel.size() >= sizeof(addr.sun_path))
- throw Error(format("socket path `%1%' is too long") % socketPathRel);
- strcpy(addr.sun_path, socketPathRel.c_str());
-
- unlink(socketPath.c_str());
-
- /* Make sure that the socket is created with 0666 permission
- (everybody can connect --- provided they have access to the
- directory containing the socket). */
- mode_t oldMode = umask(0111);
- int res = bind(fdSocket, (struct sockaddr *) &addr, sizeof(addr));
- umask(oldMode);
- if (res == -1)
- throw SysError(format("cannot bind to socket `%1%'") % socketPath);
-
- if (chdir("/") == -1) /* back to the root */
- throw SysError("cannot change current directory");
-
- if (listen(fdSocket, 5) == -1)
- throw SysError(format("cannot listen on socket `%1%'") % socketPath);
- }
-
- closeOnExec(fdSocket);
-
- /* Loop accepting connections. */
- while (1) {
-
- try {
- /* Important: the server process *cannot* open the SQLite
- database, because it doesn't like forks very much. */
- assert(!store);
-
- /* Accept a connection. */
- struct sockaddr_un remoteAddr;
- socklen_t remoteAddrLen = sizeof(remoteAddr);
-
- AutoCloseFD remote = accept(fdSocket,
- (struct sockaddr *) &remoteAddr, &remoteAddrLen);
- checkInterrupt();
- if (remote == -1) {
- if (errno == EINTR)
- continue;
- else
- throw SysError("accepting connection");
- }
-
- closeOnExec(remote);
-
- bool trusted = false;
- pid_t clientPid = -1;
-
+ uid_t clientUid = (uid_t) -1;
+ gid_t clientGid = (gid_t) -1;
+
+ try {
+ /* Important: the server process *cannot* open the SQLite
+ database, because it doesn't like forks very much. */
+ assert(!store);
+
+ /* Accept a connection. */
+ struct sockaddr_storage remoteAddr;
+ socklen_t remoteAddrLen = sizeof(remoteAddr);
+
+ try_again:
+ AutoCloseFD remote = accept(fdSocket,
+ (struct sockaddr *) &remoteAddr, &remoteAddrLen);
+ checkInterrupt();
+ if (remote == -1) {
+ if (errno == EINTR)
+ goto try_again;
+ else
+ throw SysError("accepting connection");
+ }
+
+ closeOnExec(remote);
+
+ pid_t clientPid = -1;
+ bool trusted = false;
+
+ /* Get the identity of the caller, if possible. */
+ if (remoteAddr.ss_family == AF_UNIX) {
#if defined(SO_PEERCRED)
- /* Get the identity of the caller, if possible. */
- ucred cred;
- socklen_t credLen = sizeof(cred);
- if (getsockopt(remote, SOL_SOCKET, SO_PEERCRED, &cred, &credLen) == -1)
- throw SysError("getting peer credentials");
+ ucred cred;
+ socklen_t credLen = sizeof(cred);
+ if (getsockopt(remote, SOL_SOCKET, SO_PEERCRED,
+ &cred, &credLen) == -1)
+ throw SysError("getting peer credentials");
- clientPid = cred.pid;
+ clientPid = cred.pid;
+ clientUid = cred.uid;
+ clientGid = cred.gid;
+ trusted = clientUid == 0;
struct passwd * pw = getpwuid(cred.uid);
string user = pw ? pw->pw_name : std::to_string(cred.uid);
- struct group * gr = getgrgid(cred.gid);
- string group = gr ? gr->gr_name : std::to_string(cred.gid);
-
- Strings trustedUsers = settings.get("trusted-users", Strings({"root"}));
- Strings allowedUsers = settings.get("allowed-users", Strings({"*"}));
-
- if (matchUser(user, group, trustedUsers))
- trusted = true;
-
- if (!trusted && !matchUser(user, group, allowedUsers))
- throw Error(format("user `%1%' is not allowed to connect to the Nix daemon") % user);
-
- printMsg(lvlInfo, format((string) "accepted connection from pid %1%, user %2%"
- + (trusted ? " (trusted)" : "")) % clientPid % user);
+ printMsg(lvlInfo,
+ format((string) "accepted connection from pid %1%, user %2%")
+ % clientPid % user);
#endif
+ } else {
+ char address_str[128];
+ const char *result;
- /* Fork a child to handle the connection. */
- startProcess([&]() {
- fdSocket.close();
+ if (remoteAddr.ss_family == AF_INET) {
+ struct sockaddr_in *addr = (struct sockaddr_in *) &remoteAddr;
+ struct in_addr inaddr = { addr->sin_addr };
+ result = inet_ntop(AF_INET, &inaddr,
+ address_str, sizeof address_str);
+ } else if (remoteAddr.ss_family == AF_INET6) {
+ struct sockaddr_in6 *addr = (struct sockaddr_in6 *) &remoteAddr;
+ struct in6_addr inaddr = { addr->sin6_addr };
+ result = inet_ntop(AF_INET6, &inaddr,
+ address_str, sizeof address_str);
+ } else {
+ result = NULL;
+ }
+
+ if (result != NULL) {
+ printMsg(lvlInfo,
+ format("accepted connection from %1%")
+ % address_str);
+ }
+ }
+
+ /* Fork a child to handle the connection. */
+ startProcess([&]() {
+ close(fdSocket);
/* Background the daemon. */
if (setsid() == -1)
@@ -968,17 +905,11 @@ static void daemonLoop()
strncpy(argvSaved[1], processName.c_str(), strlen(argvSaved[1]));
}
-#if defined(SO_PEERCRED)
/* Store the client's user and group for this connection. This
has to be done in the forked process since it is per
- connection. */
- settings.clientUid = cred.uid;
- settings.clientGid = cred.gid;
-#else
- /* Setting these to -1 means: do not change */
- settings.clientUid = (uid_t) -1;
- settings.clientGid = (gid_t) -1;
-#endif
+ connection. Setting these to -1 means: do not change. */
+ settings.clientUid = clientUid;
+ settings.clientGid = clientGid;
/* Handle the connection. */
from.fd = remote;
@@ -988,23 +919,63 @@ static void daemonLoop()
exit(0);
}, false, "unexpected Nix daemon error: ", true);
- } catch (Interrupted & e) {
- throw;
- } catch (Error & e) {
- printMsg(lvlError, format("error processing connection: %1%") % e.msg());
- }
+ } catch (Interrupted & e) {
+ throw;
+ } catch (Error & e) {
+ printMsg(lvlError, format("error processing connection: %1%") % e.msg());
}
}
-
-void run(Strings args)
+static void daemonLoop(const std::vector<int>& sockets)
{
- for (Strings::iterator i = args.begin(); i != args.end(); ) {
- string arg = *i++;
- if (arg == "--daemon") /* ignored for backwards compatibility */;
+ if (chdir("/") == -1)
+ throw SysError("cannot change current directory");
+
+ /* Get rid of children automatically; don't let them become
+ zombies. */
+ setSigChldAction(true);
+
+ /* Mark sockets as close-on-exec. */
+ for(int fd: sockets) {
+ closeOnExec(fd);
}
- daemonLoop();
+ /* Prepare the FD set corresponding to SOCKETS. */
+ auto initializeFDSet = [&](fd_set *set) {
+ FD_ZERO(set);
+ for (int fd: sockets) {
+ FD_SET(fd, set);
+ }
+ };
+
+ /* Loop accepting connections. */
+ while (1) {
+ fd_set readfds;
+
+ initializeFDSet(&readfds);
+ int count =
+ select(*std::max_element(sockets.begin(), sockets.end()) + 1,
+ &readfds, NULL, NULL,
+ NULL);
+ if (count < 0) {
+ int err = errno;
+ if (err == EINTR)
+ continue;
+ throw SysError(format("select error: %1%") % strerror(err));
+ }
+
+ for (unsigned int i = 0; i < sockets.size(); i++) {
+ if (FD_ISSET(sockets[i], &readfds)) {
+ acceptConnection(sockets[i]);
+ }
+ }
+ }
+}
+
+
+void run(const std::vector<int>& sockets)
+{
+ daemonLoop(sockets);
}
diff --git a/tests/guix-daemon.sh b/tests/guix-daemon.sh
index 9186ffd58..7212e3eb6 100644
--- a/tests/guix-daemon.sh
+++ b/tests/guix-daemon.sh
@@ -81,6 +81,18 @@ guile -c "
kill "$daemon_pid"
+# Pass several '--listen' options, and make sure they are all honored.
+guix-daemon --disable-chroot --listen="$socket" --listen="$socket-second" \
+ --listen="localhost" --listen="localhost:9876" &
+daemon_pid=$!
+
+for uri in "$socket" "$socket-second" \
+ "guix://localhost" "guix://localhost:9876"
+do
+ GUIX_DAEMON_SOCKET="$uri" guix build guile-bootstrap
+done
+
+kill "$daemon_pid"
# Check the failed build cache.
--
2.13.1
^ permalink raw reply related [flat|nested] 8+ messages in thread