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-rw-r--r--source3/lib/server_prefork.c688
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;
+}
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