void
lwan_init(lwan_t *l)
{
int max_threads = sysconf(_SC_NPROCESSORS_ONLN);
struct rlimit r;
/* Load defaults */
memcpy(&l->config, &default_config, sizeof(default_config));
/* Initialize status first, as it is used by other things during
* their initialization. */
lwan_status_init(l);
/* These will only print debugging messages. Debug messages are always
* printed if we're on a debug build, so the quiet setting will be
* respected. */
lwan_job_thread_init();
lwan_response_init();
lwan_tables_init();
/* Load the configuration file. */
if (!setup_from_config(l))
lwan_status_warning("Could not read config file, using defaults");
/* Continue initialization as normal. */
lwan_status_debug("Initializing lwan web server");
l->thread.count = max_threads > 0 ? max_threads : 2;
if (getrlimit(RLIMIT_NOFILE, &r) < 0)
lwan_status_critical_perror("getrlimit");
if (r.rlim_max == RLIM_INFINITY)
r.rlim_cur *= 8;
else if (r.rlim_cur < r.rlim_max)
r.rlim_cur = r.rlim_max;
if (setrlimit(RLIMIT_NOFILE, &r) < 0)
lwan_status_critical_perror("setrlimit");
l->conns = calloc(r.rlim_cur, sizeof(lwan_connection_t));
l->thread.max_fd = r.rlim_cur / l->thread.count;
lwan_status_info("Using %d threads, maximum %d sockets per thread",
l->thread.count, l->thread.max_fd);
for (--r.rlim_cur; r.rlim_cur; --r.rlim_cur)
l->conns[r.rlim_cur].response_buffer = strbuf_new();
srand(time(NULL));
signal(SIGPIPE, SIG_IGN);
close(STDIN_FILENO);
lwan_thread_init(l);
lwan_socket_init(l);
lwan_http_authorize_init();
}
static void
allocate_connections(lwan_t *l, size_t max_open_files)
{
l->conns = calloc(max_open_files, sizeof(lwan_connection_t));
if (!l->conns)
lwan_status_critical_perror("calloc");
}
static int
setup_socket_from_systemd(void)
{
int fd = SD_LISTEN_FDS_START;
if (!sd_is_socket_inet(fd, AF_UNSPEC, SOCK_STREAM, 1, 0))
lwan_status_critical("Passed file descriptor is not a "
"listening TCP socket");
int flags = fcntl(fd, F_GETFD);
if (flags < 0)
lwan_status_critical_perror("Could not obtain socket flags");
if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) < 0)
lwan_status_critical_perror("Could not set socket flags");
return fd;
}
static void allocate_connections(struct lwan *l, size_t max_open_files)
{
const size_t sz = max_open_files * sizeof(struct lwan_connection);
if (posix_memalign((void **)&l->conns, 64, align_to_size(sz, 64)))
lwan_status_critical_perror("aligned_alloc");
memset(l->conns, 0, sz);
}
static rlim_t setup_open_file_count_limits(void)
{
struct rlimit r;
if (getrlimit(RLIMIT_NOFILE, &r) < 0)
lwan_status_critical_perror("getrlimit");
if (r.rlim_max != r.rlim_cur) {
if (r.rlim_max == RLIM_INFINITY)
r.rlim_cur = OPEN_MAX;
else if (r.rlim_cur < r.rlim_max)
r.rlim_cur = r.rlim_max;
if (setrlimit(RLIMIT_NOFILE, &r) < 0)
lwan_status_critical_perror("setrlimit");
}
return r.rlim_cur;
}
static void
allocate_connections(lwan_t *l, size_t max_open_files)
{
#if defined(_ISOC11_SOURCE)
const size_t sz = max_open_files * sizeof(lwan_connection_t);
l->conns = aligned_alloc(64, sz);
if (!l->conns)
lwan_status_critical_perror("aligned_alloc");
memset(l->conns, 0, sz);
#else
l->conns = calloc(max_open_files, sizeof(lwan_connection_t));
if (!l->conns)
lwan_status_critical_perror("calloc");
#endif
}
static struct lwan_url_map *add_url_map(struct lwan_trie *t, const char *prefix,
const struct lwan_url_map *map)
{
struct lwan_url_map *copy = malloc(sizeof(*copy));
if (!copy)
lwan_status_critical_perror("Could not copy URL map");
memcpy(copy, map, sizeof(*copy));
copy->prefix = strdup(prefix ? prefix : copy->prefix);
if (!copy->prefix)
lwan_status_critical_perror("Could not copy URL prefix");
copy->prefix_len = strlen(copy->prefix);
lwan_trie_add(t, copy->prefix, copy);
return copy;
}
void lwan_straitjacket_enforce(config_t *c, config_line_t *l)
{
char *user_name = NULL;
char *chroot_path = NULL;
uid_t uid;
gid_t gid;
if (geteuid() != 0) {
config_error(c, "Straitjacket requires root privileges");
return;
}
while (config_read_line(c, l)) {
switch (l->type) {
case CONFIG_LINE_TYPE_LINE:
/* TODO: limit_syscalls */
if (!strcmp(l->line.key, "user")) {
user_name = strdupa(l->line.value);
} else if (!strcmp(l->line.key, "chroot")) {
chroot_path = strdupa(l->line.value);
} else {
config_error(c, "Invalid key: %s", l->line.key);
return;
}
break;
case CONFIG_LINE_TYPE_SECTION:
config_error(c, "Straitjacket accepts no sections");
return;
case CONFIG_LINE_TYPE_SECTION_END:
if (!get_user_uid_gid(user_name, &uid, &gid)) {
config_error(c, "Unknown user: %s", user_name);
return;
}
if (chroot_path) {
if (chroot(chroot_path) < 0) {
lwan_status_critical_perror("Could not chroot() to %s",
chroot_path);
}
lwan_status_debug("Jailed to %s", chroot_path);
}
if (!switch_to_user(uid, gid, user_name)) {
lwan_status_critical("Could not drop privileges to %s, aborting",
user_name);
}
return;
}
}
config_error(c, "Expecting section end while parsing straitjacket");
}
void
lwan_trie_add(struct lwan_trie *trie, const char *key, void *data)
{
if (UNLIKELY(!trie || !key || !data))
return;
struct lwan_trie_node **knode, *node;
const char *orig_key = key;
/* Traverse the trie, allocating nodes if necessary */
for (knode = &trie->root; *key; knode = &node->next[(int)(*key++ & 7)])
GET_NODE();
/* Get the leaf node (allocate it if necessary) */
GET_NODE();
struct lwan_trie_leaf *leaf = find_leaf_with_key(node, orig_key, (size_t)(key - orig_key));
bool had_key = leaf;
if (!leaf) {
leaf = malloc(sizeof(*leaf));
if (!leaf)
lwan_status_critical_perror("malloc");
} else if (trie->free_node) {
trie->free_node(leaf->data);
}
leaf->data = data;
if (!had_key) {
leaf->key = strdup(orig_key);
leaf->next = node->leaf;
node->leaf = leaf;
}
return;
oom:
lwan_status_critical_perror("calloc");
}
static void
create_thread(lwan_t *l, lwan_thread_t *thread)
{
pthread_attr_t attr;
memset(thread, 0, sizeof(*thread));
thread->lwan = l;
if ((thread->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
lwan_status_critical_perror("epoll_create");
if (pthread_attr_init(&attr))
lwan_status_critical_perror("pthread_attr_init");
if (pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM))
lwan_status_critical_perror("pthread_attr_setscope");
if (pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE))
lwan_status_critical_perror("pthread_attr_setdetachstate");
if (pipe2(thread->pipe_fd, O_NONBLOCK | O_CLOEXEC) < 0)
lwan_status_critical_perror("pipe");
struct epoll_event event = { .events = EPOLLIN, .data.ptr = NULL };
if (epoll_ctl(thread->epoll_fd, EPOLL_CTL_ADD, thread->pipe_fd[0], &event) < 0)
lwan_status_critical_perror("epoll_ctl");
if (pthread_create(&thread->self, &attr, thread_io_loop, thread))
lwan_status_critical_perror("pthread_create");
if (pthread_attr_destroy(&attr))
lwan_status_critical_perror("pthread_attr_destroy");
}
void
lwan_thread_add_client(lwan_thread_t *t, int fd)
{
t->lwan->conns[fd].flags = 0;
t->lwan->conns[fd].thread = t;
if (UNLIKELY(write(t->pipe_fd[1], &fd, sizeof(int)) < 0))
lwan_status_perror("write");
}
void lwan_set_url_map(struct lwan *l, const struct lwan_url_map *map)
{
lwan_trie_destroy(&l->url_map_trie);
if (UNLIKELY(!lwan_trie_init(&l->url_map_trie, destroy_urlmap)))
lwan_status_critical_perror("Could not initialize trie");
for (; map->prefix; map++) {
struct lwan_url_map *copy = add_url_map(&l->url_map_trie, NULL, map);
if (copy->module && copy->module->create) {
copy->data = copy->module->create (map->prefix, copy->args);
copy->flags = copy->module->flags;
copy->handler = copy->module->handle_request;
} else {
copy->flags = HANDLER_PARSE_MASK;
}
}
}
static int
listen_addrinfo(int fd, const struct addrinfo *addr)
{
if (listen(fd, get_backlog_size()) < 0)
lwan_status_critical_perror("listen");
char host_buf[NI_MAXHOST], serv_buf[NI_MAXSERV];
int ret = getnameinfo(addr->ai_addr, addr->ai_addrlen, host_buf, sizeof(host_buf),
serv_buf, sizeof(serv_buf), NI_NUMERICHOST | NI_NUMERICSERV);
if (ret)
lwan_status_critical("getnameinfo: %s", gai_strerror(ret));
if (addr->ai_family == AF_INET6)
lwan_status_info("Listening on http://[%s]:%s", host_buf, serv_buf);
else
lwan_status_info("Listening on http://%s:%s", host_buf, serv_buf);
return fd;
}
void lwan_set_url_map(lwan_t *l, const lwan_url_map_t *map)
{
lwan_trie_destroy(&l->url_map_trie);
if (UNLIKELY(!lwan_trie_init(&l->url_map_trie, destroy_urlmap)))
lwan_status_critical_perror("Could not initialize trie");
for (; map->prefix; map++) {
lwan_url_map_t *copy = add_url_map(&l->url_map_trie, NULL, map);
if (UNLIKELY(!copy))
continue;
if (copy->module && copy->module->init) {
copy->data = copy->module->init(copy->args);
copy->flags = copy->module->flags;
copy->handler = copy->module->handle;
} else {
copy->flags = HANDLER_PARSE_MASK;
}
}
}
static ALWAYS_INLINE void
_push_request_fd(lwan_t *l, int fd)
{
unsigned thread;
#ifdef __x86_64__
assert(sizeof(lwan_connection_t) == 32);
/* Since lwan_connection_t is guaranteed to be 32-byte long, two of them
* can fill up a cache line. This formula will group two connections
* per thread in a way that false-sharing is avoided. This gives wrong
* results when fd=0, but this shouldn't happen (as 0 is either the
* standard input or the main socket, but even if that changes,
* scheduling will still work). */
thread = ((fd - 1) / 2) % l->thread.count;
#else
static int counter = 0;
thread = counter++ % l->thread.count;
#endif
int epoll_fd = l->thread.threads[thread].epoll_fd;
struct epoll_event event = {
.events = EPOLLIN | EPOLLRDHUP | EPOLLERR | EPOLLET,
.data.ptr = &l->conns[fd]
};
l->conns[fd].flags = 0;
l->conns[fd].thread = &l->thread.threads[thread];
if (UNLIKELY(epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &event) < 0))
lwan_status_critical_perror("epoll_ctl");
}
static void
_signal_handler(int signal_number)
{
lwan_status_info("Signal %d (%s) received",
signal_number, strsignal(signal_number));
longjmp(cleanup_jmp_buf, 1);
}
static lwan_connection_t *
grab_and_watch_client(int epoll_fd, int pipe_fd, lwan_connection_t *conns)
{
int fd;
if (UNLIKELY(read(pipe_fd, &fd, sizeof(int)) != sizeof(int))) {
lwan_status_perror("read");
return NULL;
}
struct epoll_event event = {
.events = events_by_write_flag[1],
.data.ptr = &conns[fd]
};
if (UNLIKELY(epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &event) < 0))
lwan_status_critical_perror("epoll_ctl");
return &conns[fd];
}
static void *
thread_io_loop(void *data)
{
lwan_thread_t *t = data;
const int epoll_fd = t->epoll_fd;
const int read_pipe_fd = t->pipe_fd[0];
const int max_events = min((int)t->lwan->thread.max_fd, 1024);
lwan_connection_t *conns = t->lwan->conns;
struct epoll_event *events;
coro_switcher_t switcher;
struct death_queue_t dq;
int n_fds;
lwan_status_debug("Starting IO loop on thread #%d",
(unsigned short)(ptrdiff_t)(t - t->lwan->thread.threads) + 1);
events = calloc((size_t)max_events, sizeof(*events));
if (UNLIKELY(!events))
lwan_status_critical("Could not allocate memory for events");
death_queue_init(&dq, conns, t->lwan->config.keep_alive_timeout);
for (;;) {
switch (n_fds = epoll_wait(epoll_fd, events, max_events,
death_queue_epoll_timeout(&dq))) {
case -1:
switch (errno) {
case EBADF:
case EINVAL:
goto epoll_fd_closed;
}
continue;
case 0: /* timeout: shutdown waiting sockets */
death_queue_kill_waiting(&dq);
break;
default: /* activity in some of this poller's file descriptor */
update_date_cache(t);
for (struct epoll_event *ep_event = events; n_fds--; ep_event++) {
lwan_connection_t *conn;
if (!ep_event->data.ptr) {
conn = grab_and_watch_client(epoll_fd, read_pipe_fd, conns);
if (UNLIKELY(!conn))
continue;
spawn_or_reset_coro_if_needed(conn, &switcher, &dq);
} else {
conn = ep_event->data.ptr;
if (UNLIKELY(ep_event->events & (EPOLLRDHUP | EPOLLHUP))) {
destroy_coro(&dq, conn);
continue;
}
spawn_or_reset_coro_if_needed(conn, &switcher, &dq);
resume_coro_if_needed(&dq, conn, epoll_fd);
}
death_queue_move_to_last(&dq, conn);
}
}
}
epoll_fd_closed:
free(events);
return NULL;
}
static void lwan_fd_watch_init(struct lwan *l)
{
l->epfd = epoll_create1(EPOLL_CLOEXEC);
if (l->epfd < 0)
lwan_status_critical_perror("epoll_create1");
}