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server.c
1331 lines (1021 loc) · 30.3 KB
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server.c
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/*
* Copyright (c) 2005-2012 by KoanLogic s.r.l. <http://www.koanlogic.com>
* All rights reserved.
*
* This file is part of KLone, and as such it is subject to the license stated
* in the LICENSE file which you have received as part of this distribution.
*
* $Id: server.c,v 1.70 2009/11/26 09:11:33 stewy Exp $
*/
#include "klone_conf.h"
#include <sys/types.h>
#include <sys/stat.h>
#ifdef HAVE_SYS_WAIT
#include <sys/wait.h>
#endif
#include <u/libu.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <klone/server.h>
#include <klone/backend.h>
#include <klone/os.h>
#include <klone/timer.h>
#include <klone/context.h>
#include <klone/ppc.h>
#include <klone/ppc_cmd.h>
#include <klone/utils.h>
#include <klone/klog.h>
#include <klone/hook.h>
#include <klone/hookprv.h>
#include <klone/server_ppc_cmd.h>
#include <klone/emb.h>
#include "server_s.h"
#include "child.h"
#define SERVER_MAX_BACKENDS 8
enum watch_fd_e
{
WATCH_FD_READ = 1 << 1,
WATCH_FD_WRITE = 1 << 2,
WATCH_FD_EXCP = 1 << 3
};
static void server_watch_fd(server_t *s, int fd, unsigned int mode);
static void server_clear_fd(server_t *s, int fd, unsigned int mode);
static void server_close_fd(server_t *s, int fd);
static int server_be_listen(backend_t *be)
{
dbg_return_if (be == NULL, ~0);
dbg_return_if (be->na == NULL, ~0);
/* Return a socket descriptor bound to the configured endpoint. */
warn_return_if ((be->ld = u_net_sd_by_addr(be->na)) == -1, ~0);
return 0;
}
#ifdef OS_UNIX
/* remove a child process whose pid is 'pid' to children list */
static int server_reap_child(server_t *s, pid_t pid)
{
child_t *child;
backend_t *be;
dbg_err_if (s == NULL);
/* get the child object */
dbg_err_if(children_get_by_pid(s->children, pid, &child));
/* remove the child from the list */
dbg_err_if(children_del(s->children, child));
be = child->be;
/* check that the minimum number of process are active */
be->nchild--;
if(be->nchild < be->start_child)
be->fork_child = be->start_child - be->nchild;
U_FREE(child);
return 0;
err:
return ~0;
}
/* add a child to the list */
static int server_add_child(server_t *s, pid_t pid, backend_t *be)
{
child_t *child = NULL;
dbg_err_if (s == NULL);
dbg_err_if (be == NULL);
dbg_err_if(child_create(pid, be, &child));
dbg_err_if(children_add(s->children, child));
be->nchild++;
return 0;
err:
return ~0;
}
/* send 'sig' signal to all children process */
static int server_signal_children(server_t *s, int sig)
{
child_t *child;
ssize_t i;
dbg_return_if (s == NULL, ~0);
for(i = children_count(s->children) - 1; i >= 0; --i)
{
if(!children_getn(s->children, i, &child))
dbg_err_if(kill(child->pid, sig) < 0);
}
return 0;
err:
dbg_strerror(errno);
return ~0;
}
#endif
static void server_term_children(server_t *s)
{
dbg_ifb(s == NULL) return;
#ifdef OS_UNIX
server_signal_children(s, SIGTERM);
#endif
return;
}
static void server_kill_children(server_t *s)
{
dbg_ifb(s == NULL) return;
#ifdef OS_UNIX
server_signal_children(s, SIGKILL);
#endif
return;
}
static void server_sigint(int sig)
{
u_unused_args(sig);
u_warn("SIGINT");
if(ctx && ctx->server)
server_stop(ctx->server);
emb_term();
}
static void server_sigterm(int sig)
{
u_unused_args(sig);
/* child process die immediately.
* note: don't call debug functions because the parent process could be
* already dead if the user used the "killall kloned" command */
if(ctx->pipc)
_exit(0);
u_warn("SIGTERM");
if(ctx && ctx->server)
server_stop(ctx->server);
}
#ifdef OS_UNIX
static void server_sigchld(int sig)
{
server_t *s = ctx->server;
u_unused_args(sig);
s->reap_children = 1;
}
static void server_waitpid(server_t *s)
{
pid_t pid = -1;
int status;
dbg_ifb(s == NULL) return;
u_sig_block(SIGCHLD);
/* detach from child processes */
while((pid = waitpid(-1, &status, WNOHANG)) > 0)
{
if(WIFEXITED(status) && WEXITSTATUS(status) != EXIT_SUCCESS)
u_warn("pid [%u], exit code [%d]", pid, WEXITSTATUS(status));
if(WIFSIGNALED(status))
u_warn("pid [%u], signal [%d]", pid, WTERMSIG(status));
/* decrement child count */
server_reap_child(s, pid);
}
s->reap_children = 0;
u_sig_unblock(SIGCHLD);
}
#endif
static void server_recalc_hfd(server_t *s)
{
register int i;
fd_set *prdfds, *pwrfds, *pexfds;
dbg_ifb(s == NULL) return;
prdfds = &s->rdfds;
pwrfds = &s->wrfds;
pexfds = &s->exfds;
/* set s->hfd to highest value */
for(i = s->hfd, s->hfd = 0; i > 0; --i)
{
if(FD_ISSET(i, prdfds) || FD_ISSET(i, pwrfds) || FD_ISSET(i, pexfds))
{
s->hfd = i;
break;
}
}
}
static void server_clear_fd(server_t *s, int fd, unsigned int mode)
{
dbg_ifb(s == NULL) return;
if(mode & WATCH_FD_READ)
FD_CLR(fd, &s->rdfds);
if(mode & WATCH_FD_WRITE)
FD_CLR(fd, &s->wrfds);
if(mode & WATCH_FD_EXCP)
FD_CLR(fd, &s->exfds);
server_recalc_hfd(s);
}
static void server_watch_fd(server_t *s, int fd, unsigned int mode)
{
dbg_ifb(s == NULL) return;
dbg_ifb(fd < 0) return;
if(mode & WATCH_FD_READ)
FD_SET(fd, &s->rdfds);
if(mode & WATCH_FD_WRITE)
FD_SET(fd, &s->wrfds);
if(mode & WATCH_FD_EXCP)
FD_SET(fd, &s->exfds);
s->hfd = U_MAX(s->hfd, fd);
}
static void server_close_fd(server_t *s, int fd)
{
dbg_ifb(s == NULL) return;
dbg_ifb(fd < 0) return;
server_clear_fd(s, fd, WATCH_FD_READ | WATCH_FD_WRITE | WATCH_FD_EXCP);
close(fd);
}
static int server_be_accept(server_t *s, backend_t *be, int *pfd)
{
struct sockaddr sa;
int sa_len = sizeof(struct sockaddr);
int ad;
u_unused_args(s);
dbg_return_if (be == NULL, ~0);
dbg_return_if (pfd == NULL, ~0);
again:
ad = accept(be->ld, &sa, &sa_len);
if(ad == -1 && errno == EINTR)
goto again; /* interrupted */
dbg_err_if(ad == -1); /* accept error */
*pfd = ad;
return 0;
err:
if(ad < 0)
warn_strerror(errno);
return ~0;
}
static int server_backend_detach(server_t *s, backend_t *be)
{
s->nbackend--;
dbg_return_if (s == NULL, ~0);
dbg_return_if (be == NULL, ~0);
u_net_addr_free(be->na);
be->server = NULL;
be->na = NULL;
be->config = NULL;
close(be->ld);
be->ld = -1;
backend_free(be);
return 0;
}
#ifdef OS_UNIX
static int server_chroot_to(server_t *s, const char *dir)
{
dbg_return_if (s == NULL, ~0);
dbg_return_if (dir == NULL, ~0);
u_unused_args(s);
dbg_err_if(chroot(dir));
dbg_err_if(chdir("/"));
u_info("chroot'd: %s", dir);
return 0;
err:
warn_strerror(errno);
return ~0;
}
static int server_foreach_cb(struct dirent *d, const char *path, void *arg)
{
int *pfound = (int*)arg;
u_unused_args(d, path);
*pfound = 1;
return ~0;
}
static int server_chroot_blind(server_t *s)
{
#ifdef HAVE_FORK
enum { BLIND_DIR_MODE = 0100 }; /* blind dir mode must be 0100 */
char dir[U_PATH_MAX];
struct stat st;
int fd_dir = -1, found;
pid_t child;
unsigned int mask;
dbg_err_if (s == NULL);
dbg_err_if (s->chroot == NULL);
dbg_err_if(u_path_snprintf(dir, U_PATH_MAX, U_PATH_SEPARATOR,
"%s/kloned_blind_chroot_%d.dir", s->chroot, getpid()));
/* create the blind dir (0100 mode) */
dbg_err_if(mkdir(dir, BLIND_DIR_MODE ));
/* get the fd of the dir */
dbg_err_if((fd_dir = open(dir, O_RDONLY, 0)) < 0);
dbg_err_if((child = fork()) < 0);
if(child == 0)
{ /* child */
/* delete the chroot dir and exit */
sleep(1); // FIXME use a lock here
u_dbg("[child] removing dir: %s\n", dir);
rmdir(dir);
_exit(0);
}
/* parent */
/* do chroot */
dbg_err_if(server_chroot_to(s, dir));
/* do some dir sanity checks */
/* get stat values */
dbg_err_if(fstat(fd_dir, &st));
/* the dir owned must be root */
dbg_err_if(st.st_gid || st.st_uid);
/* the dir mode must be 0100 */
dbg_err_if((st.st_mode & 07777) != BLIND_DIR_MODE);
/* the dir must be empty */
found = 0;
mask = S_IFIFO | S_IFCHR | S_IFDIR | S_IFBLK | S_IFREG | S_IFLNK | S_IFSOCK;
dbg_err_if(u_foreach_dir_item("/", mask, server_foreach_cb, &found));
/* bail out if the dir is not empty */
dbg_err_if(found);
close(fd_dir);
return 0;
err:
if(fd_dir >= 0)
close(fd_dir);
warn_strerror(errno);
return ~0;
#else /* !HAVE_FORK */
u_unused_args(s);
err("Blind chroot could not be honoured since fork(2) unavailable");
return ~0;
#endif /* HAVE_FORK */
}
static int server_chroot(server_t *s)
{
dbg_return_if (s == NULL, ~0);
if(s->blind_chroot)
return server_chroot_blind(s);
else
return server_chroot_to(s, s->chroot);
}
static int server_drop_privileges(server_t *s)
{
uid_t uid;
gid_t gid;
dbg_return_if (s == NULL, ~0);
if(s->gid > 0)
{
gid = (gid_t)s->gid;
/* remove all groups except gid */
dbg_err_if(setgroups(1, &gid));
/* set gid */
dbg_err_if(setgid(gid));
dbg_err_if(setegid(gid));
/* verify */
dbg_err_if(getgid() != gid || getegid() != gid);
}
if(s->uid > 0)
{
uid = (uid_t)s->uid;
/* set uid */
dbg_err_if(setuid(uid));
dbg_err_if(seteuid(uid));
/* verify */
dbg_err_if(getuid() != uid || geteuid() != uid);
}
return 0;
err:
warn_strerror(errno);
return ~0;
}
static int server_fork_child(server_t *s, backend_t *be)
{
#ifdef HAVE_FORK
backend_t *obe; /* other backed */
pid_t child;
int socks[2];
dbg_return_if (s == NULL, -1);
dbg_return_if (be == NULL, -1);
/* exit on too much children */
dbg_return_if (children_count(s->children) == s->max_child, -1);
dbg_return_if (be->nchild == be->max_child, -1);
/* create a parent<->child IPC channel */
dbg_err_if(socketpair(AF_UNIX, SOCK_STREAM, 0, socks) < 0);
if((child = fork()) == 0)
{ /* child */
/* never flush, the parent process will */
s->klog_flush = 0;
/* reseed the PRNG */
srand(rand() + getpid() + time(0));
/* close one end of the channel */
close(socks[0]);
/* save parent PPC socket and close the other */
ctx->pipc = socks[1];
ctx->backend = be;
/* close listening sockets of other backends */
LIST_FOREACH(obe, &s->bes, np)
{
if(obe == be)
continue;
close(obe->ld);
obe->ld = -1;
}
/* clear child copy of children list */
dbg_err_if(children_clear(s->children));
} else if(child > 0) {
/* parent */
/* save child pid and increment child count */
server_add_child(s, child, be);
/* close one end of the channel */
close(socks[1]);
/* watch the PPC socket connected to the child */
server_watch_fd(s, socks[0], WATCH_FD_READ);
} else {
warn_err("fork error");
}
return child;
err:
warn_strerror(errno);
return -1;
#else /* !HAVE_FORK */
u_unused_args(s, be);
u_warn("Only iterative mode is enabled (fork(2) unsupported by target OS)");
return -1;
#endif /* HAVE_FORK */
}
static int server_child_serve(server_t *s, backend_t *be, int ad)
{
pid_t child;
dbg_return_if (s == NULL, ~0);
dbg_return_if (be == NULL, ~0);
dbg_err_if((child = server_fork_child(s, be)) < 0);
if(child == 0)
{ /* child */
/* close this be listening descriptor */
close(be->ld);
hook_call(child_init);
/* serve the page */
dbg_if(backend_serve(be, ad));
hook_call(child_term);
/* close client socket and die */
close(ad);
server_stop(be->server);
}
/* parent */
return 0;
err:
warn_strerror(errno);
return ~0;
}
static int server_cb_spawn_child(talarm_t *al, void *arg)
{
server_t *s = (server_t*)arg;
u_unused_args(al);
dbg_err_if (s == NULL);
/* must be called by a child process */
dbg_err_if(ctx->backend == NULL || ctx->pipc == 0);
/* ask the parent to create a new worker child process */
dbg_err_if(server_ppc_cmd_fork_child(s, ctx->backend));
/* mark the current child process so it will die when finishes
serving this page */
server_stop(s);
return 0;
err:
return ~0;
}
#endif /* ifdef OS_UNIX */
static int server_be_serve(server_t *s, backend_t *be, int ad)
{
talarm_t *al = NULL;
dbg_err_if (s == NULL);
dbg_err_if (be == NULL);
switch(be->model)
{
#if defined(OS_UNIX) && defined(HAVE_FORK)
case SERVER_MODEL_FORK:
/* spawn a child to handle the request */
dbg_err_if(server_child_serve(s, be, ad));
break;
case SERVER_MODEL_PREFORK:
/* FIXME lower timeout value may be needed */
/* if _serve takes more then 1 second spawn a new worker process */
dbg_err_if(timerm_add(1, server_cb_spawn_child, (void*)s, &al));
/* serve the page */
dbg_if(backend_serve(be, ad));
/* remove and free the alarm */
timerm_del(al); /* prefork */
break;
#endif /* OS_UNIX && HAVE_FORK */
case SERVER_MODEL_ITERATIVE:
/* serve the page */
dbg_if(backend_serve(be, ad));
break;
default:
warn_err_if("server model not supported");
}
/* close the accepted (already served) socket */
close(ad);
return 0;
err:
close(ad);
return ~0;
}
int server_stop(server_t *s)
{
dbg_err_if (s == NULL);
if(ctx->pipc)
{ /* child process */
dbg_err_if(ctx->backend == NULL);
/* close child listening sockets to force accept(2) to exit */
close(ctx->backend->ld);
}
/* stop the parent process */
s->stop = 1;
return 0;
err:
return ~0;
}
static int server_listen(server_t *s)
{
backend_t *be;
dbg_err_if (s == NULL);
LIST_FOREACH(be, &s->bes, np)
{
dbg_err_if(server_be_listen(be));
/* watch the listening socket */
if(be->model != SERVER_MODEL_PREFORK)
server_watch_fd(s, be->ld, WATCH_FD_READ);
}
return 0;
err:
return ~0;
}
int server_cgi(server_t *s)
{
backend_t *be;
dbg_err_if (s == NULL);
/* use the first http backend as the CGI backend */
LIST_FOREACH(be, &s->bes, np)
{
if(strcasecmp(be->proto, "http") == 0)
{
hook_call(server_init);
dbg_if(backend_serve(be, 0));
hook_call(server_term);
return 0;
}
}
err: /* fall through if search loop exhausted */
return ~0;
}
ppc_t* server_get_ppc(server_t *s)
{
dbg_return_if (s == NULL, NULL);
return s->ppc;
}
static int server_process_ppc(server_t *s, int fd)
{
unsigned char cmd;
char data[PPC_MAX_DATA_SIZE];
ssize_t n;
dbg_err_if (s == NULL);
dbg_err_if (fd < 0);
/* get a ppc request */
n = ppc_read(s->ppc, fd, &cmd, data, PPC_MAX_DATA_SIZE);
if(n > 0)
{
/* process a ppc (parent procedure call) request */
dbg_err_if(ppc_dispatch(s->ppc, fd, cmd, data, n));
} else if(n == 0) {
/* child has exit or closed the channel. close our side of the sock
and remove it from the watch list */
server_close_fd(s, fd);
} else {
/* ppc error. close fd and remove it from the watch list */
server_close_fd(s, fd);
}
return 0;
err:
return ~0;
}
static int server_dispatch(server_t *s, int fd)
{
backend_t *be;
int ad = -1;
dbg_err_if (s == NULL);
/* find the backend that listen on fd */
LIST_FOREACH(be, &s->bes, np)
if(be->ld == fd)
break;
if(be == NULL) /* a child is ppc-calling */
return server_process_ppc(s, fd);
/* accept the pending connection */
dbg_err_if(server_be_accept(s, be, &ad));
/* Disable Nagle on the socket. Note that this may fail if the socket is
* in the UNIX family or it is using the SCTP transport instead of TCP. */
(void) u_net_nagle_off(ad);
/* serve the page */
dbg_err_if(server_be_serve(s, be, ad));
return 0;
err:
U_CLOSE(ad);
return ~0;
}
int server_cb_klog_flush(talarm_t *a, void *arg)
{
server_t *s = (server_t*)arg;
u_unused_args(a);
dbg_return_if (s == NULL, ~0);
/* set a flag to flush the klog object in server_loop */
s->klog_flush++;
return 0;
}
#ifdef OS_UNIX
int server_spawn_child(server_t *s, backend_t *be)
{
size_t c;
int rc;
dbg_err_if (s == NULL);
dbg_err_if (be == NULL);
dbg_err_if((rc = server_fork_child(s, be)) < 0);
if(rc > 0)
return 0; /* parent */
/* call the hook that runs the on-child user code */
hook_call(child_init);
/* child main loop:
close on s->stop or if max # of request limit has reached (the
server will respawn a new process if needed) */
for(c = 0; !s->stop && c < be->max_rq_xchild; ++c)
{
/* wait for a new client (will block on accept(2)) */
dbg_err_if(server_dispatch(s, be->ld));
}
/* before child shutdowns call the term hook */
hook_call(child_term);
server_stop(s);
return 0;
err:
return ~0;
}
/* spawn pre-fork child processes */
static int server_spawn_children(server_t *s)
{
backend_t *be;
register size_t i;
dbg_err_if (s == NULL);
/* spawn N child process that will sleep asap into accept(2) */
LIST_FOREACH (be, &s->bes, np)
{
if(be->model != SERVER_MODEL_PREFORK || be->fork_child == 0)
continue;
/* spawn be->fork_child child processes */
for(i = 0; i < be->fork_child; ++i)
{
dbg_err_if(server_spawn_child(s, be));
/* child context? */
if(ctx->pipc)
break; /* the child previously spawned is dying, exit */
be->fork_child--;
}
}
return 0;
err:
return ~0;
}
#endif
int server_loop(server_t *s)
{
struct timeval tv;
int rc, fd;
fd_set rdfds, wrfds, exfds;
dbg_err_if (s == NULL);
dbg_err_if (s->config == NULL);
dbg_err_if(server_listen(s));
#ifdef OS_UNIX
/* if it's configured chroot to the dst dir */
if(s->chroot)
dbg_err_if(server_chroot(s));
/* set uid/gid to non-root user */
warn_err_sifm(server_drop_privileges(s), "unable to drop priviledges");
/* if allow_root is not set check that we're not running as root */
if(!s->allow_root)
warn_err_ifm(!getuid() || !geteuid() || !getgid() || !getegid(),
"you must set the allow_root config option to run kloned as root");
#elif OS_WIN
if(s->chroot)
dbg_err_if(SetCurrentDirectory(s->chroot) == 0);
#endif
/* server startup hook */
hook_call(server_init);
for(; !s->stop; )
{
#ifdef OS_UNIX
/* spawn new child if needed (may fail on resource limits) */
dbg_if(server_spawn_children(s));
#endif
/* children in pre-fork mode exit here */
if(ctx->pipc)
break;
memcpy(&rdfds, &s->rdfds, sizeof(fd_set));
memcpy(&wrfds, &s->wrfds, sizeof(fd_set));
memcpy(&exfds, &s->exfds, sizeof(fd_set));
again:
/* wake up every second */
tv.tv_sec = 1; tv.tv_usec = 0;
rc = select(1 + s->hfd, &rdfds, &wrfds, &exfds, &tv);
if(rc == -1 && errno == EINTR)
goto again; /* interrupted */
dbg_err_if(rc == -1); /* select error */
#ifdef OS_UNIX
if(s->reap_children)
server_waitpid(s);
#endif
/* parent only */
if(ctx->pipc == 0)
{
/* call klog_flush if flush timeout has expired and select() timeouts */
if(s->klog_flush)
{
/* flush the log buffer */
klog_flush(s->klog);
/* reset the flag */
s->klog_flush = 0;
U_FREE(s->al_klog_flush);
/* re-set the timer */
dbg_err_if(timerm_add(SERVER_LOG_FLUSH_TIMEOUT,
server_cb_klog_flush, s, &s->al_klog_flush));
}
/* server loop hook - trigger only upon timeout and not upon client request */
if(rc == 0)
hook_call(server_loop);
}
/* for each signaled listening descriptor */
for(fd = 0; rc && fd < 1 + s->hfd; ++fd)
{
if(FD_ISSET(fd, &rdfds))
{
--rc;
/* dispatch the request to the right backend */
dbg_if(server_dispatch(s, fd));
}
} /* for each ready fd */
} /* !s->stop */
/* children in fork mode exit here */
if(ctx->pipc)
return 0;
/* server shutdown hook */
hook_call(server_term);
/* shutdown all children */
server_term_children(s);
sleep(1);
/* brute kill children process */
if(s->nchild)
server_kill_children(s);
return 0;
err:
return ~0;
}
int server_free(server_t *s)
{
backend_t *be;
dbg_err_if (s == NULL);
/* remove the hook (that needs the server_t object) */
u_log_set_hook(NULL, NULL, NULL, NULL);
/* remove klog flushing alarm */
if(s->al_klog_flush)
{
timerm_del(s->al_klog_flush);
s->al_klog_flush = NULL;
}