heimdal/lib/ipc/server.c

/*
 * Copyright (c) 2009 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "hi_locl.h"
#include <assert.h>

struct heim_sipc {
    int (*release)(heim_sipc ctx);
    heim_ipc_callback callback;
    void *userctx;
    void *mech;
};

#if defined(__APPLE__) && defined(HAVE_GCD)

#include "heim_ipcServer.h"
#include "heim_ipc_reply.h"
#include "heim_ipc_async.h"

static dispatch_source_t timer;
static dispatch_queue_t timerq;
static uint64_t timeoutvalue;

static dispatch_queue_t eventq;

static dispatch_queue_t workq;

static void
default_timer_ev(void)
{
    exit(0);
}

static void (*timer_ev)(void) = default_timer_ev;

static void
set_timer(void)
{
    dispatch_source_set_timer(timer,
			      dispatch_time(DISPATCH_TIME_NOW,
					    timeoutvalue * NSEC_PER_SEC),
			      timeoutvalue * NSEC_PER_SEC, 1000000); 
}

static void
init_globals(void)
{
    static dispatch_once_t once;
    dispatch_once(&once, ^{ 
	timerq = dispatch_queue_create("hiem-sipc-timer-q", NULL);
        timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, timerq);
	dispatch_source_set_event_handler(timer, ^{ timer_ev(); } );

	workq = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
	eventq = dispatch_queue_create("heim-ipc.event-queue", NULL);
    });
}

static void
suspend_timer(void)
{
    dispatch_suspend(timer);
}

static void
restart_timer(void)
{
    dispatch_sync(timerq, ^{ set_timer(); });
    dispatch_resume(timer);
}

struct mach_service {
    mach_port_t sport;
    dispatch_source_t source;
    dispatch_queue_t queue;
};

struct mach_call_ctx {
    mach_port_t reply_port;
    heim_icred cred;
    heim_idata req;
};


static void
mach_complete_sync(heim_sipc_call ctx, int returnvalue, heim_idata *reply)
{
    struct mach_call_ctx *s = (struct mach_call_ctx *)ctx;
    heim_ipc_message_inband_t replyin;
    mach_msg_type_number_t replyinCnt;
    heim_ipc_message_outband_t replyout;
    mach_msg_type_number_t replyoutCnt;
    kern_return_t kr;

    if (returnvalue) {
	/* on error, no reply */
	replyinCnt = 0;
	replyout = 0; replyoutCnt = 0;
	kr = KERN_SUCCESS;
    } else if (reply->length < 2048) {
	replyinCnt = reply->length;
	memcpy(replyin, reply->data, replyinCnt);
	replyout = 0; replyoutCnt = 0;
	kr = KERN_SUCCESS;
    } else {
	replyinCnt = 0;
	kr = vm_read(mach_task_self(), 
		     (vm_address_t)reply->data, reply->length,
		     (vm_address_t *)&replyout, &replyoutCnt);
    }

    mheim_ripc_call_reply(s->reply_port, returnvalue,
			  replyin, replyinCnt,
			  replyout, replyoutCnt);

    heim_ipc_free_cred(s->cred);
    free(s->req.data);
    free(s);
    restart_timer();
}

static void
mach_complete_async(heim_sipc_call ctx, int returnvalue, heim_idata *reply)
{
    struct mach_call_ctx *s = (struct mach_call_ctx *)ctx;
    heim_ipc_message_inband_t replyin;
    mach_msg_type_number_t replyinCnt;
    heim_ipc_message_outband_t replyout;
    mach_msg_type_number_t replyoutCnt;
    kern_return_t kr;

    if (returnvalue) {
	/* on error, no reply */
	replyinCnt = 0;
	replyout = 0; replyoutCnt = 0;
	kr = KERN_SUCCESS;
    } else if (reply->length < 2048) {
	replyinCnt = reply->length;
	memcpy(replyin, reply->data, replyinCnt);
	replyout = 0; replyoutCnt = 0;
	kr = KERN_SUCCESS;
    } else {
	replyinCnt = 0;
	kr = vm_read(mach_task_self(), 
		     (vm_address_t)reply->data, reply->length,
		     (vm_address_t *)&replyout, &replyoutCnt);
    }

    kr = mheim_aipc_acall_reply(s->reply_port, returnvalue,
				replyin, replyinCnt,
				replyout, replyoutCnt);
    heim_ipc_free_cred(s->cred);
    free(s->req.data);
    free(s);
    restart_timer();
}


kern_return_t
mheim_do_call(mach_port_t server_port,
	      audit_token_t client_creds,
	      mach_port_t reply_port,
	      heim_ipc_message_inband_t requestin,
	      mach_msg_type_number_t requestinCnt,
	      heim_ipc_message_outband_t requestout,
	      mach_msg_type_number_t requestoutCnt,
	      int *returnvalue,
	      heim_ipc_message_inband_t replyin,
	      mach_msg_type_number_t *replyinCnt,
	      heim_ipc_message_outband_t *replyout,
	      mach_msg_type_number_t *replyoutCnt)
{
    heim_sipc ctx = dispatch_get_context(dispatch_get_current_queue());
    struct mach_call_ctx *s;
    kern_return_t kr;
    uid_t uid;
    gid_t gid;
    pid_t pid;
    au_asid_t session;

    *replyout = NULL;
    *replyoutCnt = 0;
    *replyinCnt = 0;

    s = malloc(sizeof(*s));
    if (s == NULL)
	return KERN_MEMORY_FAILURE; /* XXX */
    
    s->reply_port = reply_port;
    
    audit_token_to_au32(client_creds, NULL, &uid, &gid, NULL, NULL, &pid, &session, NULL);
    
    kr = _heim_ipc_create_cred(uid, gid, pid, session, &s->cred);
    if (kr) {
	free(s);
	return kr;
    }
    
    suspend_timer();
    
    if (requestinCnt) {
	s->req.data = malloc(requestinCnt);
	memcpy(s->req.data, requestin, requestinCnt);
	s->req.length = requestinCnt;
    } else {
	s->req.data = malloc(requestoutCnt);
	memcpy(s->req.data, requestout, requestoutCnt);
	s->req.length = requestoutCnt;
    }
    
    dispatch_async(workq, ^{
	(ctx->callback)(ctx->userctx, &s->req, s->cred,
			mach_complete_sync, (heim_sipc_call)s);
    });

    return MIG_NO_REPLY;
}

kern_return_t
mheim_do_call_request(mach_port_t server_port,
		      audit_token_t client_creds,
		      mach_port_t reply_port,
		      heim_ipc_message_inband_t requestin,
		      mach_msg_type_number_t requestinCnt,
		      heim_ipc_message_outband_t requestout,
		      mach_msg_type_number_t requestoutCnt)
{
    heim_sipc ctx = dispatch_get_context(dispatch_get_current_queue());
    struct mach_call_ctx *s;
    kern_return_t kr;
    uid_t uid;
    gid_t gid;
    pid_t pid;
    au_asid_t session;
    
    s = malloc(sizeof(*s));
    if (s == NULL)
	return KERN_MEMORY_FAILURE; /* XXX */
    
    s->reply_port = reply_port;
    
    audit_token_to_au32(client_creds, NULL, &uid, &gid, NULL, NULL, &pid, &session, NULL);
    
    kr = _heim_ipc_create_cred(uid, gid, pid, session, &s->cred);
    if (kr) {
	free(s);
	return kr;
    }
    
    suspend_timer();
    
    if (requestinCnt) {
	s->req.data = malloc(requestinCnt);
	memcpy(s->req.data, requestin, requestinCnt);
	s->req.length = requestinCnt;
    } else {
	s->req.data = malloc(requestoutCnt);
	memcpy(s->req.data, requestout, requestoutCnt);
	s->req.length = requestoutCnt;
    }
    
    dispatch_async(workq, ^{
	(ctx->callback)(ctx->userctx, &s->req, s->cred,
			mach_complete_async, (heim_sipc_call)s);
    });
    
    return KERN_SUCCESS;
}

static int
mach_init(const char *service, mach_port_t sport, heim_sipc ctx)
{
    struct mach_service *s;
    char *name;

    init_globals();

    s = calloc(1, sizeof(*s));
    if (s == NULL)
	return ENOMEM;

    asprintf(&name, "heim-ipc-mach-%s", service);

    s->queue = dispatch_queue_create(name, NULL);
    free(name);
    s->sport = sport;

    s->source = dispatch_source_create(DISPATCH_SOURCE_TYPE_MACH_RECV, 
				       s->sport, 0, s->queue);
    if (s->source == NULL) {
	dispatch_release(s->queue);
	free(s);
	return ENOMEM;
    }
    ctx->mech = s;

    dispatch_set_context(s->queue, ctx);
    dispatch_set_context(s->source, s);

    dispatch_source_set_event_handler(s->source, ^{
	    dispatch_mig_server(s->source, sizeof(union __RequestUnion__mheim_do_mheim_ipc_subsystem), mheim_ipc_server);
	});

    dispatch_source_set_cancel_handler(s->source, ^{
	    heim_sipc ctx = dispatch_get_context(dispatch_get_current_queue());
	    struct mach_service *st = ctx->mech;
	    mach_port_mod_refs(mach_task_self(), st->sport, 
			       MACH_PORT_RIGHT_RECEIVE, -1);
	    dispatch_release(st->queue);
	    dispatch_release(st->source);
	    free(st);
	    free(ctx);
	});

    dispatch_resume(s->source);

    return 0;
}

static int
mach_release(heim_sipc ctx)
{
    struct mach_service *s = ctx->mech;
    dispatch_source_cancel(s->source);
    dispatch_release(s->source);
    return 0;
}

static mach_port_t
mach_checkin_or_register(const char *service)
{
    mach_port_t mp;
    kern_return_t kr;

    kr = bootstrap_check_in(bootstrap_port, service, &mp);
    if (kr == KERN_SUCCESS)
	return mp;

    /* Pre SnowLeopard version */
    kr = mach_port_allocate(mach_task_self(), MACH_PORT_RIGHT_RECEIVE, &mp);
    if (kr != KERN_SUCCESS)
	return MACH_PORT_NULL;

    kr = mach_port_insert_right(mach_task_self(), mp, mp, 
				MACH_MSG_TYPE_MAKE_SEND);
    if (kr != KERN_SUCCESS) {
	mach_port_destroy(mach_task_self(), mp);
	return MACH_PORT_NULL;
    }

    kr = bootstrap_register(bootstrap_port, rk_UNCONST(service), mp);
    if (kr != KERN_SUCCESS) {
	mach_port_destroy(mach_task_self(), mp);
	return MACH_PORT_NULL;
    }

    return mp;
}


#endif /* __APPLE__ && HAVE_GCD */


int
heim_sipc_launchd_mach_init(const char *service,
			    heim_ipc_callback callback,
			    void *user, heim_sipc *ctx)
{
#if defined(__APPLE__) && defined(HAVE_GCD)
    mach_port_t sport = MACH_PORT_NULL;
    heim_sipc c = NULL;
    int ret;

    *ctx = NULL;

    sport = mach_checkin_or_register(service);
    if (sport == MACH_PORT_NULL) {
	ret = ENOENT;
	goto error;
    }

    c = calloc(1, sizeof(*c));
    if (c == NULL) {
	ret = ENOMEM;
	goto error;
    }
    c->release = mach_release;
    c->userctx = user;
    c->callback = callback;
		 
    ret = mach_init(service, sport, c);
    if (ret)
	goto error;

    *ctx = c;
    return 0;
 error:
    if (c)
	free(c);
    if (sport != MACH_PORT_NULL)
	mach_port_mod_refs(mach_task_self(), sport, 
			   MACH_PORT_RIGHT_RECEIVE, -1);
    return ret;
#else /* !(__APPLE__ && HAVE_GCD) */
    *ctx = NULL;
    return EINVAL;
#endif /* __APPLE__ && HAVE_GCD */
}

struct client {
    int fd;
    heim_ipc_callback callback;
    void *userctx;
    int flags;
#define LISTEN_SOCKET	1
#define WAITING_READ	2
#define WAITING_WRITE	4
#define WAITING_CLOSE	8
    unsigned calls;
    size_t ptr, len;
    uint8_t *inmsg;
    size_t olen;
    uint8_t *outmsg;
#ifdef HAVE_GCD
    dispatch_source_t in;
    dispatch_source_t out;
#endif
};

#ifndef HAVE_GCD
static unsigned num_clients = 0;
static struct client **clients = NULL;
#endif

static void handle_read(struct client *);
static void handle_write(struct client *);
static int maybe_close(struct client *);

static struct client *
add_new_socket(int fd,
	       int flags,
	       heim_ipc_callback callback,
	       void *userctx)
{
    struct client *c;
    int fileflags;

    c = calloc(1, sizeof(*c));
    if (c == NULL)
	return NULL;
	
    if (flags & LISTEN_SOCKET) {
	c->fd = fd;
    } else {
	c->fd = accept(fd, NULL, NULL);
	if(c->fd < 0) {
	    free(c);
	    return NULL;
	}
    }

    c->flags = flags;
    c->callback = callback;
    c->userctx = userctx;

    fileflags = fcntl(c->fd, F_GETFL, 0);
    fcntl(c->fd, F_SETFL, fileflags | O_NONBLOCK);

#ifdef HAVE_GCD
    init_globals();
	
    c->in = dispatch_source_create(DISPATCH_SOURCE_TYPE_READ, 
				   c->fd, 0, eventq);
    c->out = dispatch_source_create(DISPATCH_SOURCE_TYPE_WRITE,
				    c->fd, 0, eventq);
    
    dispatch_source_set_event_handler(c->in, ^{ 
	    int rw = (c->flags & WAITING_WRITE);
	    handle_read(c);
	    if (rw == 0 && (c->flags & WAITING_WRITE))
		dispatch_resume(c->out);
	    if ((c->flags & WAITING_READ) == 0)
		dispatch_suspend(c->in);
	    maybe_close(c);
	});
    dispatch_source_set_event_handler(c->out, ^{
	    handle_write(c);
	    if ((c->flags & WAITING_WRITE) == 0) {
		dispatch_suspend(c->out);
	    }
	    maybe_close(c);
	});
    
    dispatch_resume(c->in);
#else
    clients = erealloc(clients, sizeof(clients[0]) * (num_clients + 1));
    clients[num_clients] = c;
    num_clients++;
#endif

    return c;
}

static int
maybe_close(struct client *c)
{
    if (c->calls != 0)
	return 0;
    if (c->flags & (WAITING_READ|WAITING_WRITE))
	return 0;

#ifdef HAVE_GCD
    dispatch_cancel(c->in);
    if ((c->flags & WAITING_READ) == 0)
	dispatch_resume(c->in);
    dispatch_release(c->in);

    dispatch_cancel(c->out);
    if ((c->flags & WAITING_WRITE) == 0)
	dispatch_resume(c->out);
    dispatch_release(c->out);
#endif
    close(c->fd); /* ref count fd close */
    free(c);
    return 1;
}


struct socket_call {
    heim_idata in;
    struct client *c;
};

static void
socket_complete(heim_sipc_call ctx, int returnvalue, heim_idata *reply)
{
    struct socket_call *sc = (struct socket_call *)ctx;
    struct client *c = sc->c;

    /* double complete ? */
    if (c == NULL)
	abort();

    if ((c->flags & WAITING_CLOSE) == 0) {
	uint8_t *ptr;
	uint32_t u32;
	size_t rlen = reply->length + sizeof(u32) + sizeof(u32);

	c->outmsg = erealloc(c->outmsg, c->olen + rlen);

	/* length */
	ptr = &c->outmsg[c->olen];
	u32 = htonl(reply->length);
	memcpy(ptr, &u32, sizeof(u32));
	ptr += sizeof(u32);

	/* return value */
	u32 = htonl(returnvalue);
	memcpy(ptr, &u32, sizeof(u32));
	ptr += sizeof(u32);

	/* data */
	memcpy(ptr, reply->data, reply->length);
	c->olen += rlen;
	c->flags |= WAITING_WRITE;
    }

    c->calls--;

    free(sc->in.data);
    sc->c = NULL; /* so we can catch double complete */
    free(sc);

    maybe_close(c);
}

static void
handle_read(struct client *c)
{
    ssize_t len;
    uint32_t dlen;

    if (c->flags & LISTEN_SOCKET) {
	add_new_socket(c->fd,
		       WAITING_READ,
		       c->callback,
		       c->userctx);
	return;
    }

    if (c->ptr - c->len < 1024) {
	c->inmsg = erealloc(c->inmsg,
			    c->len + 1024);
	c->len += 1024;
    }
    
    len = read(c->fd, c->inmsg + c->ptr, c->len - c->ptr);
    if (len <= 0) {
	c->flags |= WAITING_CLOSE;
	c->flags &= ~WAITING_READ;
	return;
    }
    c->ptr += len;
    if (c->ptr > c->len)
	abort();
    
    while (c->ptr >= sizeof(dlen)) {
	struct socket_call *cs;
	
	memcpy(&dlen, c->inmsg, sizeof(dlen));
	dlen = ntohl(dlen);
	
	if (dlen < c->ptr - sizeof(dlen))
	    break;
	
	cs = emalloc(sizeof(*cs));
	cs->c = c;
	cs->in.data = emalloc(dlen);
	memcpy(cs->in.data, c->inmsg + sizeof(dlen), dlen);
	cs->in.length = dlen;
	
	c->ptr -= sizeof(dlen) + dlen;
	memmove(c->inmsg,
		c->inmsg + sizeof(dlen) + dlen,
		c->ptr);
	
	c->calls++;
	c->callback(c->userctx, &cs->in,
		    NULL, socket_complete,
		    (heim_sipc_call)cs);
    }
}

static void
handle_write(struct client *c)
{
    ssize_t len;

    len = write(c->fd, c->outmsg, c->olen);
    if (len <= 0) {
	c->flags |= WAITING_CLOSE;
	c->flags &= ~(WAITING_WRITE);
    } else if (c->olen != len) {
	memmove(&c->outmsg[0], &c->outmsg[len], c->olen - len);
	c->olen -= len;
    } else {
	c->olen = 0;
	free(c->outmsg);
	c->outmsg = NULL;
	c->flags &= ~(WAITING_WRITE);
    }
}


#ifndef HAVE_GCD

static void
process_loop(void)
{
    struct pollfd *fds;
    unsigned n;
    unsigned num_fds;

    while(num_clients > 0) {

	fds = malloc(num_clients * sizeof(fds[0]));
	if(fds == NULL)
	    abort();

	num_fds = num_clients;

	for (n = 0 ; n < num_fds; n++) {
	    fds[n].fd = clients[n]->fd;
	    fds[n].events = 0;
	    if (clients[n]->flags & WAITING_READ)
		fds[n].events |= POLLIN;
	    if (clients[n]->flags & WAITING_WRITE)
		fds[n].events |= POLLOUT;
	    
	    fds[n].revents = 0;
	}

	poll(fds, num_fds, -1);

	for (n = 0 ; n < num_fds; n++) {
	    if (clients[n] == NULL)
		continue;
	    if (fds[n].revents & POLLERR) {
		clients[n]->flags |= WAITING_CLOSE;
		continue;
	    }

	    if (fds[n].revents & POLLIN)
		handle_read(clients[n]);
	    if (fds[n].revents & POLLOUT)
		handle_write(clients[n]);
	}

	n = 0;
	while (n < num_clients) {
	    struct client *c = clients[n];
	    if (maybe_close(c)) {
		if (n < num_clients - 1)
		    clients[n] = clients[num_clients - 1];
		num_clients--;
	    } else
		n++;
	}

	free(fds);
    }
}

#endif

static int
socket_release(heim_sipc ctx)
{
    struct client *c = ctx->mech;
    c->flags |= WAITING_CLOSE;
    return 0;
}

int
heim_sipc_launchd_stream_fd_init(int fd,
				 heim_ipc_callback callback,
				 void *user, heim_sipc *ctx)
{
    heim_sipc ct = calloc(1, sizeof(*ct));
    struct client *c;

    c = add_new_socket(fd, LISTEN_SOCKET|WAITING_READ, callback, user);

    ct->mech = c;
    ct->release = socket_release;
    *ctx = ct;
    return 0;
}


int
heim_sipc_service_unix(const char *service,
		       heim_ipc_callback callback,
		       void *user, heim_sipc *ctx)
{
    struct sockaddr_un un;
    int fd;

    un.sun_family = AF_UNIX;

    snprintf(un.sun_path, sizeof(un.sun_path),
	     "/var/run/.heim_%s-socket", service);
    fd = socket(AF_UNIX, SOCK_STREAM, 0);
    if (fd < 0)
	return errno;

    socket_set_reuseaddr(fd, 1);
#ifdef LOCAL_CREDS
    {
	int one = 1;
	setsockopt(fd, 0, LOCAL_CREDS, (void *)&one, sizeof(one));
    }
#endif

    unlink(un.sun_path);

    if (bind(fd, (struct sockaddr *)&un, sizeof(un)) < 0) {
	close(fd);
	return errno;
    }

    if (listen(fd, SOMAXCONN) < 0) {
	close(fd);
	return errno;
    }

    chmod(un.sun_path, 0666);

    return heim_sipc_launchd_stream_fd_init(fd, callback, user, ctx);
}



/**
 * Set the idle timeout value

 * The timeout event handler is triggered recurrently every idle
 * period `t'. The default action is rather draconian and just calls
 * exit(0), so you might want to change this to something more
 * graceful using heim_sipc_set_timeout_handler().
 */

void
heim_sipc_timeout(time_t t)
{
#ifdef HAVE_GCD
    static dispatch_once_t timeoutonce;
    init_globals();
    dispatch_sync(timerq, ^{
	    timeoutvalue = t;
	    set_timer();
	});
    dispatch_once(&timeoutonce, ^{  dispatch_resume(timer); });
#else
    abort();
#endif
}

/**
 * Set the timeout event handler
 *
 * Replaces the default idle timeout action.
 */

void
heim_sipc_set_timeout_handler(void (*func)(void))
{
#ifdef HAVE_GCD
    init_globals();
    dispatch_sync(timerq, ^{ timer_ev = func; });
#else
    abort();
#endif
}


void
heim_sipc_free_context(heim_sipc ctx)
{
    (ctx->release)(ctx);
}

void
heim_ipc_main(void)
{
#ifdef HAVE_GCD
    dispatch_main();
#else
    process_loop();
#endif
}