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-rw-r--r--source3/lib/server_prefork.c502
-rw-r--r--source3/lib/server_prefork.h76
2 files changed, 578 insertions, 0 deletions
diff --git a/source3/lib/server_prefork.c b/source3/lib/server_prefork.c
new file mode 100644
index 0000000000..4aa3f482cc
--- /dev/null
+++ b/source3/lib/server_prefork.c
@@ -0,0 +1,502 @@
+/*
+ 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 "system/time.h"
+#include "system/shmem.h"
+#include "system/filesys.h"
+#include "server_prefork.h"
+#include "../lib/util/util.h"
+
+struct prefork_pool {
+
+ int listen_fd;
+ int lock_fd;
+
+ prefork_main_fn_t *main_fn;
+ void *private_data;
+
+ int pool_size;
+ struct pf_worker_data *pool;
+};
+
+int prefork_pool_destructor(struct prefork_pool *pfp)
+{
+ munmap(pfp->pool, pfp->pool_size * sizeof(struct pf_worker_data));
+ return 0;
+}
+
+bool prefork_create_pool(struct tevent_context *ev_ctx,
+ TALLOC_CTX *mem_ctx, int listen_fd,
+ 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;
+
+ pfp = talloc(mem_ctx, struct prefork_pool);
+ if (!pfp) {
+ DEBUG(1, ("Out of memory!\n"));
+ return false;
+ }
+ pfp->listen_fd = listen_fd;
+ pfp->main_fn = main_fn;
+ pfp->private_data = private_data;
+
+ pfp->lock_fd = create_unlink_tmp(NULL);
+ if (pfp->lock_fd == -1) {
+ DEBUG(1, ("Failed to create prefork lock fd!\n"));
+ talloc_free(pfp);
+ return false;
+ }
+
+ pfp->pool_size = max_children;
+ data_size = sizeof(struct pf_worker_data) * max_children;
+
+ pfp->pool = mmap(NULL, data_size, PROT_READ|PROT_WRITE,
+ MAP_SHARED|MAP_ANONYMOUS, -1, 0);
+ if (pfp->pool == MAP_FAILED) {
+ 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++) {
+ pid = sys_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_IDLE;
+
+ ret = pfp->main_fn(ev_ctx, &pfp->pool[i],
+ pfp->listen_fd, pfp->lock_fd,
+ pfp->private_data);
+ exit(ret);
+
+ default: /* THE PARENT */
+ pfp->pool[i].pid = pid;
+ pfp->pool[i].started = now;
+ break;
+ }
+ }
+
+ *pf_pool = pfp;
+ return true;
+}
+
+int prefork_add_children(struct tevent_context *ev_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;
+ }
+
+ pid = sys_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_IDLE;
+ ret = pfp->main_fn(ev_ctx, &pfp->pool[i],
+ pfp->listen_fd, pfp->lock_fd,
+ pfp->private_data);
+
+ pfp->pool[i].status = PF_WORKER_EXITING;
+ exit(ret);
+
+ default: /* THE PARENT */
+ pfp->pool[i].pid = pid;
+ pfp->pool[i].started = now;
+ 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)
+{
+ struct prefork_oldest *a = (struct prefork_oldest *)ap;
+ struct prefork_oldest *b = (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 prefork_pool *pfp,
+ int num_children, time_t age_limit)
+{
+ 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_IDLE) {
+ 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_IDLE &&
+ 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;
+ kill(pfp->pool[i].pid, SIGHUP);
+ j++;
+ }
+ }
+
+ return j;
+}
+
+int prefork_count_active_children(struct prefork_pool *pfp, int *total)
+{
+ 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].num_clients == 0) {
+ continue;
+ }
+
+ a++;
+ }
+
+ *total = t;
+ return a;
+}
+
+/* to be used to finally mark a children as dead, so that it's slot can
+ * be reused */
+bool prefork_mark_pid_dead(struct prefork_pool *pfp, pid_t pid)
+{
+ int i;
+
+ for (i = 0; i < pfp->pool_size; i++) {
+ if (pfp->pool[i].pid == pid) {
+ if (pfp->pool[i].status != PF_WORKER_EXITING) {
+ DEBUG(2, ("pid %d terminated abnormally!\n",
+ (int)pid));
+ }
+
+ /* reset all fields,
+ * this makes status = PF_WORK_NONE */
+ memset(&pfp->pool[i], 0,
+ sizeof(struct pf_worker_data));
+
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/* ==== Functions used by children ==== */
+
+static SIG_ATOMIC_T pf_alarm;
+
+static void pf_alarm_cb(int signum)
+{
+ pf_alarm = 1;
+}
+
+
+/*
+ * Parameters:
+ * pf - the worker shared data structure
+ * lock_fd - the file descriptor used for locking
+ * timeout - expressed in seconds:
+ * -1 never timeouts,
+ * 0 timeouts immediately
+ * N seconds before timing out
+ *
+ * Returns values:
+ * negative errno on fatal error
+ * 0 on success to acquire lock
+ * -1 on timeout/lock held by other
+ * -2 on server msg to terminate
+ * ERRNO on other errors
+ */
+
+static int prefork_grab_lock(struct pf_worker_data *pf,
+ int lock_fd, int timeout)
+{
+ struct flock lock;
+ int op;
+ int ret;
+
+ if (pf->cmds == PF_SRV_MSG_EXIT) {
+ return -2;
+ }
+
+ pf_alarm = 0;
+
+ if (timeout > 0) {
+ CatchSignal(SIGALRM, pf_alarm_cb);
+ alarm(timeout);
+ }
+
+ if (timeout == 0) {
+ op = F_SETLK;
+ } else {
+ op = F_SETLKW;
+ }
+
+ ret = 0;
+ do {
+ ZERO_STRUCT(lock);
+ lock.l_type = F_WRLCK;
+ lock.l_whence = SEEK_SET;
+
+ ret = fcntl(lock_fd, op, &lock);
+ if (ret == 0) break;
+
+ ret = errno;
+
+ if (pf->cmds == PF_SRV_MSG_EXIT) {
+ ret = -2;
+ goto done;
+ }
+
+ switch (ret) {
+ case EINTR:
+ break;
+
+ case EACCES:
+ case EAGAIN:
+ /* lock held by other proc */
+ ret = -1;
+ goto done;
+ default:
+ goto done;
+ }
+
+ if (pf_alarm == 1) {
+ /* timed out */
+ ret = -1;
+ goto done;
+ }
+ } while (timeout != 0);
+
+ if (ret != 0) {
+ /* We have the Lock */
+ pf->status = PF_WORKER_ACCEPTING;
+ }
+
+done:
+ if (timeout > 0) {
+ alarm(0);
+ CatchSignal(SIGALRM, SIG_IGN);
+ }
+
+ if (ret > 0) {
+ DEBUG(1, ("Failed to get lock (%d, %s)!\n",
+ ret, strerror(ret)));
+ }
+ return ret;
+}
+
+/*
+ * Parameters:
+ * pf - the worker shared data structure
+ * lock_fd - the file descriptor used for locking
+ * timeout - expressed in seconds:
+ * -1 never timeouts,
+ * 0 timeouts immediately
+ * N seconds before timing out
+ *
+ * Returns values:
+ * negative errno on fatal error
+ * 0 on success to release lock
+ * -1 on timeout
+ * ERRNO on error
+ */
+
+static int prefork_release_lock(struct pf_worker_data *pf,
+ int lock_fd, int timeout)
+{
+ struct flock lock;
+ int op;
+ int ret;
+
+ pf_alarm = 0;
+
+ if (timeout > 0) {
+ CatchSignal(SIGALRM, pf_alarm_cb);
+ alarm(timeout);
+ }
+
+ if (timeout == 0) {
+ op = F_SETLK;
+ } else {
+ op = F_SETLKW;
+ }
+
+ do {
+ ZERO_STRUCT(lock);
+ lock.l_type = F_UNLCK;
+ lock.l_whence = SEEK_SET;
+
+ ret = fcntl(lock_fd, op, &lock);
+ if (ret == 0) break;
+
+ ret = errno;
+
+ if (ret != EINTR) {
+ goto done;
+ }
+
+ if (pf_alarm == 1) {
+ /* timed out */
+ ret = -1;
+ goto done;
+ }
+ } while (timeout != 0);
+
+done:
+ if (timeout > 0) {
+ alarm(0);
+ CatchSignal(SIGALRM, SIG_IGN);
+ }
+
+ if (ret > 0) {
+ DEBUG(1, ("Failed to release lock (%d, %s)!\n",
+ ret, strerror(ret)));
+ }
+ return ret;
+}
+
+/* returns:
+ * negative errno on error
+ * -2 if server commands to terminate
+ * 0 if all ok
+ * ERRNO on other errors
+ */
+
+int prefork_wait_for_client(struct pf_worker_data *pf,
+ int lock_fd, int listen_fd,
+ struct sockaddr *addr,
+ socklen_t *addrlen, int *fd)
+{
+ int ret;
+ int sd = -1;
+ int err;
+
+ ret = prefork_grab_lock(pf, lock_fd, -1);
+ if (ret != 0) {
+ return ret;
+ }
+
+ err = 0;
+ do {
+ sd = accept(listen_fd, addr, addrlen);
+
+ if (sd != -1) break;
+
+ if (errno == EINTR) {
+ if (pf->cmds == PF_SRV_MSG_EXIT) {
+ err = -2;
+ }
+ } else {
+ err = errno;
+ }
+
+ } while ((sd == -1) && (err == 0));
+
+ /* return lock now, even if the accept failed.
+ * if it takes more than 10 seconds we are in deep trouble */
+ ret = prefork_release_lock(pf, lock_fd, 2);
+ if (ret != 0) {
+ /* we were unable to release the lock!! */
+ DEBUG(0, ("Terminating due to fatal failure!\n"));
+
+ /* Just exit we cannot hold the whole server, better to error
+ * on this one client and hope it was a transiet problem */
+ err = -2;
+ }
+
+ if (err != 0) {
+ if (sd != -1) {
+ close(sd);
+ sd = -1;
+ }
+ return err;
+ }
+
+ pf->status = PF_WORKER_BUSY;
+ pf->num_clients++;
+ *fd = sd;
+ return 0;
+}
diff --git a/source3/lib/server_prefork.h b/source3/lib/server_prefork.h
new file mode 100644
index 0000000000..d6d7bf95c9
--- /dev/null
+++ b/source3/lib/server_prefork.h
@@ -0,0 +1,76 @@
+/*
+ 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 "system/network.h"
+#include <tevent.h>
+
+enum pf_worker_status {
+ PF_WORKER_NONE = 0,
+ PF_WORKER_IDLE,
+ PF_WORKER_ACCEPTING,
+ PF_WORKER_BUSY,
+ PF_WORKER_EXITING
+};
+
+enum pf_server_cmds {
+ PF_SRV_MSG_NONE = 0,
+ PF_SRV_MSG_EXIT
+};
+
+struct pf_worker_data {
+ pid_t pid;
+ enum pf_worker_status status;
+ enum pf_server_cmds cmds;
+ time_t started;
+ time_t last_used;
+ int num_clients;
+};
+
+typedef int (prefork_main_fn_t)(struct tevent_context *ev,
+ struct pf_worker_data *pf,
+ int listen_fd,
+ int lock_fd,
+ void *private_data);
+
+struct prefork_pool;
+
+
+/* ==== Functions used by controlling process ==== */
+
+bool prefork_create_pool(struct tevent_context *ev_ctx,
+ TALLOC_CTX *mem_ctx, int listen_fd,
+ int min_children, int max_children,
+ prefork_main_fn_t *main_fn, void *private_data,
+ struct prefork_pool **pf_pool);
+
+int prefork_add_children(struct tevent_context *ev_ctx,
+ struct prefork_pool *pfp,
+ int num_children);
+int prefork_retire_children(struct prefork_pool *pfp,
+ int num_children, time_t age_limit);
+int prefork_count_active_children(struct prefork_pool *pfp, int *total);
+bool prefork_mark_pid_dead(struct prefork_pool *pfp, pid_t pid);
+
+/* ==== Functions used by children ==== */
+
+int prefork_wait_for_client(struct pf_worker_data *pf,
+ int lock_fd, int listen_fd,
+ struct sockaddr *addr,
+ socklen_t *addrlen, int *fd);
generated by cgit (git 2.34.1) at 2024-12-29 10:30:16 +0000