Imported Upstream version 4.0.0+dfsg1upstream/4.0.0+dfsg1

1 files changed, 688 insertions, 0 deletions

diff --git a/source3/lib/server_prefork.c b/source3/lib/server_prefork.c
new file mode 100644
index 0000000000..3d35e1c6ca
--- /dev/null
+++ b/source3/lib/server_prefork.c
@@ -0,0 +1,688 @@
+/*
+   Unix SMB/CIFS implementation.
+   Common server globals
+
+   Copyright (C) Simo Sorce <idra@samba.org> 2011
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "serverid.h"
+#include "messages.h"
+#include "system/time.h"
+#include "system/shmem.h"
+#include "system/filesys.h"
+#include "server_prefork.h"
+#include "../lib/util/samba_util.h"
+#include "../lib/util/tevent_unix.h"
+
+struct prefork_pool {
+
+	int listen_fd_size;
+	int *listen_fds;
+
+	prefork_main_fn_t *main_fn;
+	void *private_data;
+
+	int pool_size;
+	struct pf_worker_data *pool;
+
+	int allowed_clients;
+
+	prefork_sigchld_fn_t *sigchld_fn;
+	void *sigchld_data;
+};
+
+static bool prefork_setup_sigchld_handler(struct tevent_context *ev_ctx,
+					    struct prefork_pool *pfp);
+
+static int prefork_pool_destructor(struct prefork_pool *pfp)
+{
+	anonymous_shared_free(pfp->pool);
+	return 0;
+}
+
+bool prefork_create_pool(TALLOC_CTX *mem_ctx,
+			 struct tevent_context *ev_ctx,
+			 struct messaging_context *msg_ctx,
+			 int listen_fd_size, int *listen_fds,
+			 int min_children, int max_children,
+			 prefork_main_fn_t *main_fn, void *private_data,
+			 struct prefork_pool **pf_pool)
+{
+	struct prefork_pool *pfp;
+	pid_t pid;
+	time_t now = time(NULL);
+	size_t data_size;
+	int ret;
+	int i;
+	bool ok;
+
+	pfp = talloc_zero(mem_ctx, struct prefork_pool);
+	if (!pfp) {
+		DEBUG(1, ("Out of memory!\n"));
+		return false;
+	}
+	pfp->listen_fd_size = listen_fd_size;
+	pfp->listen_fds = talloc_array(pfp, int, listen_fd_size);
+	if (!pfp->listen_fds) {
+		DEBUG(1, ("Out of memory!\n"));
+		return false;
+	}
+	for (i = 0; i < listen_fd_size; i++) {
+		pfp->listen_fds[i] = listen_fds[i];
+		/* force sockets in non-blocking mode */
+		set_blocking(listen_fds[i], false);
+	}
+	pfp->main_fn = main_fn;
+	pfp->private_data = private_data;
+
+	pfp->pool_size = max_children;
+	data_size = sizeof(struct pf_worker_data) * max_children;
+
+	pfp->pool = (struct pf_worker_data *)anonymous_shared_allocate(
+		data_size);
+	if (pfp->pool == NULL) {
+		DEBUG(1, ("Failed to mmap memory for prefork pool!\n"));
+		talloc_free(pfp);
+		return false;
+	}
+	talloc_set_destructor(pfp, prefork_pool_destructor);
+
+	for (i = 0; i < min_children; i++) {
+
+		pfp->pool[i].allowed_clients = 1;
+		pfp->pool[i].started = now;
+
+		pid = fork();
+		switch (pid) {
+		case -1:
+			DEBUG(1, ("Failed to prefork child n. %d !\n", i));
+			break;
+
+		case 0: /* THE CHILD */
+
+			pfp->pool[i].status = PF_WORKER_ALIVE;
+			ret = pfp->main_fn(ev_ctx, msg_ctx,
+					   &pfp->pool[i], i + 1,
+					   pfp->listen_fd_size,
+					   pfp->listen_fds,
+					   pfp->private_data);
+			exit(ret);
+
+		default: /* THE PARENT */
+			pfp->pool[i].pid = pid;
+			break;
+		}
+	}
+
+	ok = prefork_setup_sigchld_handler(ev_ctx, pfp);
+	if (!ok) {
+		DEBUG(1, ("Failed to setup SIGCHLD Handler!\n"));
+		talloc_free(pfp);
+		return false;
+	}
+
+	*pf_pool = pfp;
+	return true;
+}
+
+/* Provide the new max children number in new_max
+ * (must be larger than current max).
+ * Returns: 0 if all fine
+ *	    ENOSPC if mremap fails to expand
+ *	    EINVAL if new_max is invalid
+ */
+int prefork_expand_pool(struct prefork_pool *pfp, int new_max)
+{
+	struct prefork_pool *pool;
+	size_t old_size;
+	size_t new_size;
+	int ret;
+
+	if (new_max <= pfp->pool_size) {
+		return EINVAL;
+	}
+
+	old_size = sizeof(struct pf_worker_data) * pfp->pool_size;
+	new_size = sizeof(struct pf_worker_data) * new_max;
+
+	pool = (struct prefork_pool *)anonymous_shared_resize(
+		&pfp->pool, new_size, false);
+	if (pool == NULL) {
+		ret = errno;
+		DEBUG(3, ("Failed to mremap memory (%d: %s)!\n",
+			  ret, strerror(ret)));
+		return ret;
+	}
+
+	memset(&pool[pfp->pool_size], 0, new_size - old_size);
+
+	pfp->pool_size = new_max;
+
+	return 0;
+}
+
+int prefork_add_children(struct tevent_context *ev_ctx,
+			 struct messaging_context *msg_ctx,
+			 struct prefork_pool *pfp,
+			 int num_children)
+{
+	pid_t pid;
+	time_t now = time(NULL);
+	int ret;
+	int i, j;
+
+	for (i = 0, j = 0; i < pfp->pool_size && j < num_children; i++) {
+
+		if (pfp->pool[i].status != PF_WORKER_NONE) {
+			continue;
+		}
+
+		pfp->pool[i].allowed_clients = 1;
+		pfp->pool[i].started = now;
+
+		pid = fork();
+		switch (pid) {
+		case -1:
+			DEBUG(1, ("Failed to prefork child n. %d !\n", j));
+			break;
+
+		case 0: /* THE CHILD */
+
+			pfp->pool[i].status = PF_WORKER_ALIVE;
+			ret = pfp->main_fn(ev_ctx, msg_ctx,
+					   &pfp->pool[i], i + 1,
+					   pfp->listen_fd_size,
+					   pfp->listen_fds,
+					   pfp->private_data);
+
+			pfp->pool[i].status = PF_WORKER_EXITING;
+			exit(ret);
+
+		default: /* THE PARENT */
+			pfp->pool[i].pid = pid;
+			j++;
+			break;
+		}
+	}
+
+	DEBUG(5, ("Added %d children!\n", j));
+
+	return j;
+}
+
+struct prefork_oldest {
+	int num;
+	time_t started;
+};
+
+/* sort in inverse order */
+static int prefork_sort_oldest(const void *ap, const void *bp)
+{
+	const struct prefork_oldest *a = (const struct prefork_oldest *)ap;
+	const struct prefork_oldest *b = (const struct prefork_oldest *)bp;
+
+	if (a->started == b->started) {
+		return 0;
+	}
+	if (a->started < b->started) {
+		return 1;
+	}
+	return -1;
+}
+
+int prefork_retire_children(struct messaging_context *msg_ctx,
+			    struct prefork_pool *pfp,
+			    int num_children, time_t age_limit)
+{
+	const DATA_BLOB ping = data_blob_null;
+	time_t now = time(NULL);
+	struct prefork_oldest *oldest;
+	int i, j;
+
+	oldest = talloc_array(pfp, struct prefork_oldest, pfp->pool_size);
+	if (!oldest) {
+		return -1;
+	}
+
+	for (i = 0; i < pfp->pool_size; i++) {
+		oldest[i].num = i;
+		if (pfp->pool[i].status == PF_WORKER_ALIVE ||
+		    pfp->pool[i].status == PF_WORKER_ACCEPTING) {
+			oldest[i].started = pfp->pool[i].started;
+		} else {
+			oldest[i].started = now;
+		}
+	}
+
+	qsort(oldest, pfp->pool_size,
+		sizeof(struct prefork_oldest),
+		prefork_sort_oldest);
+
+	for (i = 0, j = 0; i < pfp->pool_size && j < num_children; i++) {
+		if (((pfp->pool[i].status == PF_WORKER_ALIVE) &&
+		     (pfp->pool[i].num_clients < 1)) &&
+		    (pfp->pool[i].started <= age_limit)) {
+			/* tell the child it's time to give up */
+			DEBUG(5, ("Retiring pid %d!\n", pfp->pool[i].pid));
+			pfp->pool[i].cmds = PF_SRV_MSG_EXIT;
+			messaging_send(msg_ctx,
+					pid_to_procid(pfp->pool[i].pid),
+					MSG_PREFORK_PARENT_EVENT, &ping);
+			j++;
+		}
+	}
+
+	return j;
+}
+
+int prefork_count_children(struct prefork_pool *pfp, int *active)
+{
+	int i, a, t;
+
+	a = 0;
+	t = 0;
+	for (i = 0; i < pfp->pool_size; i++) {
+		if (pfp->pool[i].status == PF_WORKER_NONE) {
+			continue;
+		}
+
+		t++;
+
+		if ((pfp->pool[i].status == PF_WORKER_EXITING) ||
+		    (pfp->pool[i].num_clients <= 0)) {
+			continue;
+		}
+
+		a++;
+	}
+
+	if (active) {
+		*active = a;
+	}
+	return t;
+}
+
+static void prefork_cleanup_loop(struct prefork_pool *pfp)
+{
+	int status;
+	pid_t pid;
+	int i;
+
+	/* TODO: should we use a process group id wait instead of looping ? */
+	for (i = 0; i < pfp->pool_size; i++) {
+		if (pfp->pool[i].status == PF_WORKER_NONE ||
+		    pfp->pool[i].pid == 0) {
+			continue;
+		}
+
+		pid = sys_waitpid(pfp->pool[i].pid, &status, WNOHANG);
+		if (pid > 0) {
+
+			if (pfp->pool[i].status != PF_WORKER_EXITING) {
+				DEBUG(3, ("Child (%d) terminated abnormally:"
+					  " %d\n", (int)pid, status));
+			} else {
+				DEBUG(10, ("Child (%d) terminated with status:"
+					   " %d\n", (int)pid, status));
+			}
+
+			/* reset all fields,
+			 * this makes status = PF_WORK_NONE */
+			memset(&pfp->pool[i], 0,
+				sizeof(struct pf_worker_data));
+		}
+	}
+
+}
+
+int prefork_count_allowed_connections(struct prefork_pool *pfp)
+{
+	int c;
+	int i;
+
+	c = 0;
+	for (i = 0; i < pfp->pool_size; i++) {
+		if (pfp->pool[i].status == PF_WORKER_NONE ||
+		    pfp->pool[i].status == PF_WORKER_EXITING) {
+			continue;
+		}
+
+		if (pfp->pool[i].num_clients < 0) {
+			continue;
+		}
+
+		c += pfp->pool[i].allowed_clients - pfp->pool[i].num_clients;
+	}
+
+	return c;
+}
+
+void prefork_increase_allowed_clients(struct prefork_pool *pfp, int max)
+{
+	int i;
+
+	for (i = 0; i < pfp->pool_size; i++) {
+		if (pfp->pool[i].status == PF_WORKER_NONE ||
+		    pfp->pool[i].status == PF_WORKER_EXITING) {
+			continue;
+		}
+
+		if (pfp->pool[i].num_clients < 0) {
+			continue;
+		}
+
+		if (pfp->pool[i].allowed_clients < max) {
+			pfp->pool[i].allowed_clients++;
+		}
+	}
+}
+
+void prefork_decrease_allowed_clients(struct prefork_pool *pfp)
+{
+	int i;
+
+	for (i = 0; i < pfp->pool_size; i++) {
+		if (pfp->pool[i].status == PF_WORKER_NONE ||
+		    pfp->pool[i].status == PF_WORKER_EXITING) {
+			continue;
+		}
+
+		if (pfp->pool[i].num_clients < 0) {
+			continue;
+		}
+
+		if (pfp->pool[i].allowed_clients > 1) {
+			pfp->pool[i].allowed_clients--;
+		}
+	}
+}
+
+void prefork_reset_allowed_clients(struct prefork_pool *pfp)
+{
+	int i;
+
+	for (i = 0; i < pfp->pool_size; i++) {
+		pfp->pool[i].allowed_clients = 1;
+	}
+}
+
+void prefork_send_signal_to_all(struct prefork_pool *pfp, int signal_num)
+{
+	int i;
+
+	for (i = 0; i < pfp->pool_size; i++) {
+		if (pfp->pool[i].status == PF_WORKER_NONE) {
+			continue;
+		}
+
+		kill(pfp->pool[i].pid, signal_num);
+	}
+}
+
+void prefork_warn_active_children(struct messaging_context *msg_ctx,
+				  struct prefork_pool *pfp)
+{
+	const DATA_BLOB ping = data_blob_null;
+	int i;
+
+	for (i = 0; i < pfp->pool_size; i++) {
+		if (pfp->pool[i].status == PF_WORKER_NONE) {
+			continue;
+		}
+
+		messaging_send(msg_ctx,
+				pid_to_procid(pfp->pool[i].pid),
+				MSG_PREFORK_PARENT_EVENT, &ping);
+	}
+}
+
+static void prefork_sigchld_handler(struct tevent_context *ev_ctx,
+				    struct tevent_signal *se,
+				    int signum, int count,
+				    void *siginfo, void *pvt)
+{
+	struct prefork_pool *pfp;
+
+	pfp = talloc_get_type_abort(pvt, struct prefork_pool);
+
+	/* run the cleanup function to make sure all dead children are
+	 * properly and timely retired. */
+	prefork_cleanup_loop(pfp);
+
+	if (pfp->sigchld_fn) {
+		pfp->sigchld_fn(ev_ctx, pfp, pfp->sigchld_data);
+	}
+}
+
+static bool prefork_setup_sigchld_handler(struct tevent_context *ev_ctx,
+					  struct prefork_pool *pfp)
+{
+	struct tevent_signal *se;
+
+	se = tevent_add_signal(ev_ctx, pfp, SIGCHLD, 0,
+				prefork_sigchld_handler, pfp);
+	if (!se) {
+		DEBUG(0, ("Failed to setup SIGCHLD handler!\n"));
+		return false;
+	}
+
+	return true;
+}
+
+void prefork_set_sigchld_callback(struct prefork_pool *pfp,
+				  prefork_sigchld_fn_t *sigchld_fn,
+				  void *private_data)
+{
+	pfp->sigchld_fn = sigchld_fn;
+	pfp->sigchld_data = private_data;
+}
+
+/* ==== Functions used by children ==== */
+
+struct pf_listen_state {
+	struct tevent_context *ev;
+	struct pf_worker_data *pf;
+
+	int listen_fd_size;
+	int *listen_fds;
+
+	int accept_fd;
+
+	struct tsocket_address *srv_addr;
+	struct tsocket_address *cli_addr;
+
+	int error;
+};
+
+struct pf_listen_ctx {
+	TALLOC_CTX *fde_ctx;
+	struct tevent_req *req;
+	int listen_fd;
+};
+
+static void prefork_listen_accept_handler(struct tevent_context *ev,
+					  struct tevent_fd *fde,
+					  uint16_t flags, void *pvt);
+
+struct tevent_req *prefork_listen_send(TALLOC_CTX *mem_ctx,
+					struct tevent_context *ev,
+					struct pf_worker_data *pf,
+					int listen_fd_size,
+					int *listen_fds)
+{
+	struct tevent_req *req;
+	struct pf_listen_state *state;
+	struct pf_listen_ctx *ctx;
+	struct tevent_fd *fde;
+	TALLOC_CTX *fde_ctx;
+	int i;
+
+	req = tevent_req_create(mem_ctx, &state, struct pf_listen_state);
+	if (!req) {
+		return NULL;
+	}
+
+	state->ev = ev;
+	state->pf = pf;
+	state->listen_fd_size = listen_fd_size;
+	state->listen_fds = listen_fds;
+	state->accept_fd = -1;
+	state->error = 0;
+
+	fde_ctx = talloc_new(state);
+	if (tevent_req_nomem(fde_ctx, req)) {
+		return tevent_req_post(req, ev);
+	}
+
+	/* race on accept */
+	for (i = 0; i < state->listen_fd_size; i++) {
+		ctx = talloc(fde_ctx, struct pf_listen_ctx);
+		if (tevent_req_nomem(ctx, req)) {
+			return tevent_req_post(req, ev);
+		}
+		ctx->fde_ctx = fde_ctx;
+		ctx->req = req;
+		ctx->listen_fd = state->listen_fds[i];
+
+		fde = tevent_add_fd(state->ev, fde_ctx,
+				    ctx->listen_fd, TEVENT_FD_READ,
+				    prefork_listen_accept_handler, ctx);
+		if (tevent_req_nomem(fde, req)) {
+			return tevent_req_post(req, ev);
+		}
+	}
+
+	pf->status = PF_WORKER_ACCEPTING;
+
+	return req;
+}
+
+static void prefork_listen_accept_handler(struct tevent_context *ev,
+					  struct tevent_fd *fde,
+					  uint16_t flags, void *pvt)
+{
+	struct pf_listen_state *state;
+	struct tevent_req *req;
+	struct pf_listen_ctx *ctx;
+	struct sockaddr_storage addr;
+	socklen_t addrlen;
+	int soerr = 0;
+	socklen_t solen = sizeof(soerr);
+	int sd = -1;
+	int ret;
+
+	ctx = talloc_get_type_abort(pvt, struct pf_listen_ctx);
+	req = ctx->req;
+	state = tevent_req_data(ctx->req, struct pf_listen_state);
+
+	if ((state->pf->cmds == PF_SRV_MSG_EXIT) &&
+	    (state->pf->num_clients <= 0)) {
+		/* We have been asked to exit, so drop here and the next
+		 * child will pick it up */
+		state->pf->status = PF_WORKER_EXITING;
+		state->error = EINTR;
+		goto done;
+	}
+
+	/* before proceeding check that the listening fd is ok */
+	ret = getsockopt(ctx->listen_fd, SOL_SOCKET, SO_ERROR, &soerr, &solen);
+	if (ret == -1) {
+		/* this is a fatal error, we cannot continue listening */
+		state->error = EBADF;
+		goto done;
+	}
+	if (soerr != 0) {
+		/* this is a fatal error, we cannot continue listening */
+		state->error = soerr;
+		goto done;
+	}
+
+	ZERO_STRUCT(addr);
+	addrlen = sizeof(addr);
+	sd = accept(ctx->listen_fd, (struct sockaddr *)&addr, &addrlen);
+	if (sd == -1) {
+		state->error = errno;
+		DEBUG(6, ("Accept failed! (%d, %s)\n",
+			  state->error, strerror(state->error)));
+		goto done;
+	}
+
+	state->accept_fd = sd;
+
+	ret = tsocket_address_bsd_from_sockaddr(state,
+					(struct sockaddr *)(void *)&addr,
+					addrlen, &state->cli_addr);
+	if (ret < 0) {
+		state->error = errno;
+		goto done;
+	}
+
+	ZERO_STRUCT(addr);
+	addrlen = sizeof(addr);
+	ret = getsockname(sd, (struct sockaddr *)(void *)&addr, &addrlen);
+	if (ret < 0) {
+		state->error = errno;
+		goto done;
+	}
+
+	ret = tsocket_address_bsd_from_sockaddr(state,
+					(struct sockaddr *)(void *)&addr,
+					addrlen, &state->srv_addr);
+	if (ret < 0) {
+		state->error = errno;
+		goto done;
+	}
+
+done:
+	/* do not track the listen fds anymore */
+	talloc_free(ctx->fde_ctx);
+	tevent_req_done(req);
+}
+
+int prefork_listen_recv(struct tevent_req *req,
+			TALLOC_CTX *mem_ctx, int *fd,
+			struct tsocket_address **srv_addr,
+			struct tsocket_address **cli_addr)
+{
+	struct pf_listen_state *state;
+	int ret = 0;
+
+	state = tevent_req_data(req, struct pf_listen_state);
+
+	if (state->error) {
+		ret = state->error;
+	} else {
+		tevent_req_is_unix_error(req, &ret);
+	}
+
+	if (ret) {
+		if (state->accept_fd != -1) {
+			close(state->accept_fd);
+		}
+	} else {
+		*fd = state->accept_fd;
+		*srv_addr = talloc_move(mem_ctx, &state->srv_addr);
+		*cli_addr = talloc_move(mem_ctx, &state->cli_addr);
+		state->pf->num_clients++;
+	}
+	if (state->pf->status == PF_WORKER_ACCEPTING) {
+		state->pf->status = PF_WORKER_ALIVE;
+	}
+
+	tevent_req_received(req);
+	return ret;
+}