]> git.tuebingen.mpg.de Git - paraslash.git/blobdiff - server.c
Merge branch 'refs/heads/t/clean_server_exit'
[paraslash.git] / server.c
index c3244132ccb1323eb448fa1a20a619332b71ef0d..f19fc996ecc7355ddf24379e242fcec4da287dd6 100644 (file)
--- a/server.c
+++ b/server.c
-/*
- * Copyright (C) 1997-2007 Andre Noll <maan@systemlinux.org>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
+/* Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
 
 /** \file server.c Paraslash's main server. */
 
-
-/** \mainpage Paraslash API Reference
- *
- * Starting points for getting an overview are
- *
- * probably:
- *
- *     - The main programs: \ref server.c, \ref audiod.c, \ref client.c,
- *       \ref audioc.c, \ref fsck.c
- *     - Server: \ref server_command, \ref sender,
- *     - Audio file selector: \ref audio_format_handler, \ref mood, \ref afs_table,
- *     - Client: \ref receiver, \ref receiver_node, \ref filter, \ref filter_node
- *
- *
- * The gory details, listed by topic:
- *
- *     - Audio format handlers: \ref mp3_afh.c, \ref ogg_afh.c \ref aac_afh.c
- *     - Decoders: \ref mp3dec.c, \ref \ref oggdec.c, \ref aacdec.c
- *     - Volume normalizer: \ref compress.c
- *     - Output: \ref alsa_write.c, \ref osx_write.c
- *     - http: \ref http_recv.c, \ref http_send.c
- *     - ortp: \ref ortp_recv.c, \ref ortp_send.c
- *     - dccp: \ref dccp_recv.c, \ref dccp_send.c
- *     - Audio file selector: \ref afs.c, \ref aft.c, \ref mood.c
- *     - Afs structures: \ref afs_table, \ref audio_file_data,
- *       \ref afs_info \ref audio_format_info,
- *     - Afs tables: \ref aft.c, \ref mood.c, \ref playlist.c,
- *       \ref attribute.c, \ref score.c.
- *
- * Lower levels:
- *
- *     - Scheduling: \ref sched.c, \ref sched.h
- *     - Networking: \ref net.c,
- *     - File descriptors: \ref fd.c,
- *     - Signals: \ref signal.c,
- *     - Daemons: \ref daemon.c,
- *     - Strings: \ref string.c, string.h
- *     - Time: \ref time.c, time.h
- *     - Spawning processes: \ref exec.c
- *     - Inter process communication: ipc.c,
- *     - The object storage layer: \ref osl.c,
- *     - Blob tables: blob.c,
- *     - Queueing chunks of audio data: \ref chunk_queue.c
- *     - The error subssystem: \ref error.h
- *
- * Lov-level data structures:
- *
- *     - Doubly linked lists: \ref list.h,
- *     - Red-black trees: \ref rbtree.h, \ref rbtree.c
- *     - Ring buffer: \ref ringbuffer.c, \ref ringbuffer.h
- *     - Hashing: \ref hash.h, \ref sha1.h, \ref sha1.c
- *     - Crypto: \ref crypt.c
+/**
+ * \mainpage Main data structures and selected APIs:
  *
+ *     - Senders: \ref sender,
+ *     - Audio file selector: \ref afs_info, \ref afs_table,
+ *     - Audio format handler: \ref audio_format_handler, \ref afh_info
+ *     - Receivers/filters/writers: \ref receiver, \ref receiver_node,
+ *       \ref filter, \ref filter_node, \ref writer_node, \ref writer.
+ *     - Scheduling: \ref sched.h,
+ *     - Buffer trees: \ref buffer_tree.h,
+ *     - Sideband API: \ref sideband.h,
+ *     - Crypto: \ref crypt.h, \ref crypt_backend.h,
+ *     - Error subsystem: \ref error.h,
+ *     - Inter process communication: \ref ipc.h,
+ *     - Forward error correction: \ref fec.h,
+ *     - Daemons: \ref daemon.h,
+ *     - Mixer API: \ref mix.h,
+ *     - Interactive sessions: \ref interactive.h,
+ *     - File descriptors: \ref fd.h,
+ *     - Signals: \ref signal.h,
+ *     - Networking: \ref net.h,
+ *     - Time: \ref time.c,
+ *     - Doubly linked lists: \ref list.h.
  */
 
+#include <netinet/in.h>
+#include <sys/socket.h>
 #include <signal.h>
+#include <regex.h>
+#include <osl.h>
 #include <sys/types.h>
-#include <dirent.h>
+#include <arpa/inet.h>
+#include <sys/un.h>
+#include <netdb.h>
+#include <lopsub.h>
 
+#include "server.lsg.h"
 #include "para.h"
 #include "error.h"
-#include "server.cmdline.h"
+#include "crypt.h"
 #include "afh.h"
 #include "string.h"
 #include "afs.h"
+#include "net.h"
 #include "server.h"
+#include "list.h"
+#include "send.h"
+#include "sched.h"
 #include "vss.h"
 #include "config.h"
 #include "close_on_fork.h"
-#include "send.h"
-#include "net.h"
 #include "daemon.h"
 #include "ipc.h"
 #include "fd.h"
-#include "list.h"
-#include "sched.h"
 #include "signal.h"
 #include "user_list.h"
+#include "color.h"
+#include "version.h"
 
-/** define the array of error lists needed by para_server */
-INIT_SERVER_ERRLISTS;
+/** Array of error strings. */
+DEFINE_PARA_ERRLIST;
 
-/** shut down non-authorized connections after that many seconds */
+__printf_2_3 void (*para_log)(int, const char*, ...) = daemon_log;
+
+/** Shut down non-authorized connections after that many seconds. */
 #define ALARM_TIMEOUT 10
 
 /**
  * Pointer to shared memory area for communication between para_server
- * and its children. Exported to vss.c. command.c and to afs.
+ * and its children. Exported to vss.c, command.c and to afs.
  */
 struct misc_meta_data *mmd;
 
 /**
- * the configuration of para_server
+ * The active value for all config options of para_server.
  *
- * It also contains the options for the audio file selector, audio format
- * handler and all supported senders.
+ * It is computed by merging the parse result of the command line options with
+ * the parse result of the config file.
  */
-struct server_args_info conf;
-
-/** the file containing user information (public key, permissions) */
-char *user_list_file = NULL;
-
-extern void dccp_send_init(struct sender *);
-extern void http_send_init(struct sender *);
-extern void ortp_send_init(struct sender *);
-
-/** the list of supported senders */
-struct sender senders[] = {
-       {
-               .name = "http",
-               .init = http_send_init,
-       },
-       {
-               .name = "dccp",
-               .init = dccp_send_init,
-       },
-#ifdef HAVE_ORTP
-       {
-               .name = "ortp",
-               .init = ortp_send_init,
-       },
-#endif
-       {
-               .name = NULL,
-       }
-};
+struct lls_parse_result *server_lpr = NULL;
 
+/* Command line options (no config file options). Used in handle_sighup(). */
+static struct lls_parse_result *cmdline_lpr;
 
-/* global variables for server-internal use */
-static FILE *logfile;
-static int mmd_mutex, mmd_shm_id;
-static int signal_pipe;
+/**
+ * A random number used to "authenticate" the afs connection.
+ *
+ * para_server picks this number by random before it forks the afs process. The
+ * command handlers know this number as well and write it to the afs socket,
+ * together with the id of the shared memory area which contains the payload of
+ * the afs command. A local process has to know this number to abuse the afs
+ * service provided by the local socket.
+ */
+uint32_t afs_socket_cookie;
+
+/** The mutex protecting the shared memory area containing the mmd struct. */
+int mmd_mutex;
+
+/* Serializes log output. */
+static int log_mutex;
+
+static struct sched sched;
+static struct signal_task *signal_task;
+
+/** The process id of the audio file selector process. */
+pid_t afs_pid = 0;
+
+/* The the main server process (parent of afs and the command handlers). */
+static pid_t server_pid;
 
 /**
- * para_server's log function
+ * Tell whether the executing process is a command handler.
+ *
+ * Cleanup on exit must be performed differently for command handlers.
  *
- * \param ll the log level
- * \param fmt the format string describing the log message
+ * \return True if the pid of the executing process is neither the server pid
+ * nor the afs pid.
  */
-void para_log(int ll, const char* fmt,...)
+bool process_is_command_handler(void)
 {
-       va_list argp;
-       FILE *outfd;
-       struct tm *tm;
-       time_t t1;
-       char str[MAXLINE] = "";
-       pid_t mypid;
-
-       if (ll < conf.loglevel_arg)
-               return;
-       outfd = logfile? logfile : stderr;
-       time(&t1);
-       tm = localtime(&t1);
-       strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
-       fprintf(outfd, "%s ", str);
-       if (conf.loglevel_arg <= INFO)
-               fprintf(outfd, "%i: ", ll);
-       mypid = getpid();
-       if (conf.loglevel_arg <= INFO)
-               fprintf(outfd, "(%d) ", mypid);
-       va_start(argp, fmt);
-       vfprintf(outfd, fmt, argp);
-       va_end(argp);
+       pid_t pid = getpid();
+
+       return pid != afs_pid && pid != server_pid;
 }
 
-/*
- * setup shared memory area and get mutex for locking
+/** The task responsible for server command handling. */
+struct server_command_task {
+       /** TCP port on which para_server listens for connections. */
+       int listen_fd;
+       /* File descriptor for the accepted socket. */
+       int child_fd;
+       /** Copied from para_server's main function. */
+       int argc;
+       /** Argument vector passed to para_server's main function. */
+       char **argv;
+       /** The command task structure for scheduling. */
+       struct task *task;
+};
+
+/**
+ * Return the list of tasks for the server process.
+ *
+ * This is called from \a com_tasks(). The helper is necessary since command
+ * handlers can not access the scheduler structure directly.
+ *
+ * \return A dynamically allocated string that must be freed by the caller.
  */
-static void shm_init(void)
+char *server_get_tasks(void)
+{
+       return get_task_list(&sched);
+}
+
+static void pre_log_hook(void)
+{
+       mutex_lock(log_mutex);
+}
+
+static void post_log_hook(void)
+{
+       mutex_unlock(log_mutex);
+}
+
+/* Setup shared memory area and init mutexes */
+static void init_ipc_or_die(void)
 {
        void *shm;
-       int ret = shm_new(sizeof(struct misc_meta_data));
+       int shmid, ret = shm_new(sizeof(struct misc_meta_data));
 
        if (ret < 0)
                goto err_out;
-
-       ret = shm_attach(ret, ATTACH_RW, &shm);
+       shmid = ret;
+       ret = shm_attach(shmid, ATTACH_RW, &shm);
+       shm_destroy(shmid);
        if (ret < 0)
                goto err_out;
        mmd = shm;
-       mmd_shm_id = ret;
 
        ret = mutex_new();
        if (ret < 0)
                goto err_out;
        mmd_mutex = ret;
+       ret = mutex_new();
+       if (ret < 0)
+               goto destroy_mmd_mutex;
+       log_mutex = ret;
 
        mmd->num_played = 0;
        mmd->num_commands = 0;
        mmd->events = 0;
        mmd->num_connects = 0;
        mmd->active_connections = 0;
-       strcpy(mmd->afd.path, "(none)");
        mmd->vss_status_flags = VSS_NEXT;
        mmd->new_vss_status_flags = VSS_NEXT;
-       mmd->sender_cmd_data.cmd_num = -1;
        return;
+destroy_mmd_mutex:
+       mutex_destroy(mmd_mutex);
 err_out:
-       PARA_EMERG_LOG("%s", PARA_STRERROR(-ret));
+       PARA_EMERG_LOG("%s\n", para_strerror(-ret));
        exit(EXIT_FAILURE);
 }
 
 /**
- * lock the shared memory area containing the mmd struct
+ * (Re-)read the server configuration files.
  *
- * \sa semop(2), struct misc_meta_data.
- */
-void mmd_lock(void)
-{
-       mutex_lock(mmd_mutex);
-}
-
-/**
- * unlock the shared memory area containing the mmd struct
+ * \param reload Whether config file overrides command line.
  *
- * \sa semop(2), struct misc_meta_data
+ * This function also re-opens the logfile and the user list. On SIGHUP it is
+ * called from both server and afs context.
  */
-
-void mmd_unlock(void)
+void parse_config_or_die(bool reload)
 {
-       mutex_unlock(mmd_mutex);
-}
-
-static void parse_config(int override)
-{
-       char *home = para_homedir();
-       struct stat statbuf;
        int ret;
-       char *cf;
+       char *cf = NULL, *errctx = NULL, *user_list_file = NULL;
+       void *map;
+       size_t sz;
+       int cf_argc;
+       char **cf_argv;
+       struct lls_parse_result *cf_lpr, *merged_lpr;
+       char *home = para_homedir();
 
-       if (conf.config_file_given)
-               cf = para_strdup(conf.config_file_arg);
+       if (OPT_GIVEN(CONFIG_FILE))
+               cf = para_strdup(OPT_STRING_VAL(CONFIG_FILE));
        else
                cf = make_message("%s/.paraslash/server.conf", home);
-       free(user_list_file);
-       if (!conf.user_list_given)
-               user_list_file = make_message("%s/.paraslash/server.users", home);
-       else
-               user_list_file = para_strdup(conf.user_list_arg);
-       ret = stat(cf, &statbuf);
-       if (ret && conf.config_file_given) {
-               ret = -1;
-               PARA_EMERG_LOG("can not stat config file %s\n", cf);
-               goto out;
+       if (!mmd || getpid() != afs_pid) {
+               if (OPT_GIVEN(USER_LIST))
+                       user_list_file = para_strdup(OPT_STRING_VAL(USER_LIST));
+               else
+                       user_list_file = make_message("%s/.paraslash/server.users", home);
        }
-       if (!ret) {
-               int tmp = conf.daemon_given;
-               struct server_cmdline_parser_params params = {
-                       .override = override,
-                       .initialize = 0,
-                       .check_required = 0,
-                       .check_ambiguity = 0
-               };
-               server_cmdline_parser_config_file(cf, &conf, &params);
-               conf.daemon_given = tmp;
+       free(home);
+       ret = mmap_full_file(cf, O_RDONLY, &map, &sz, NULL);
+       if (ret < 0) {
+               if (ret != -E_EMPTY && ret != -ERRNO_TO_PARA_ERROR(ENOENT))
+                       goto free_cf;
+               if (ret == -ERRNO_TO_PARA_ERROR(ENOENT) && OPT_GIVEN(CONFIG_FILE))
+                       goto free_cf;
+               server_lpr = cmdline_lpr;
+               goto success;
        }
-       /* logfile */
-       if (!conf.logfile_given && conf.daemon_given) {
-               ret = -1;
-               PARA_EMERG_LOG("%s", "daemon, but no log file\n");
-               goto out;
+       ret = lls(lls_convert_config(map, sz, NULL, &cf_argv, &errctx));
+       para_munmap(map, sz);
+       if (ret < 0)
+               goto free_cf;
+       cf_argc = ret;
+       ret = lls(lls_parse(cf_argc, cf_argv, CMD_PTR, &cf_lpr, &errctx));
+       lls_free_argv(cf_argv);
+       if (ret < 0)
+               goto free_cf;
+       if (reload) /* config file overrides command line */
+               ret = lls(lls_merge(cf_lpr, cmdline_lpr, CMD_PTR, &merged_lpr,
+                       &errctx));
+       else /* command line options override config file options */
+               ret = lls(lls_merge(cmdline_lpr, cf_lpr, CMD_PTR, &merged_lpr,
+                       &errctx));
+       lls_free_parse_result(cf_lpr, CMD_PTR);
+       if (ret < 0)
+               goto free_cf;
+       if (server_lpr != cmdline_lpr)
+               lls_free_parse_result(server_lpr, CMD_PTR);
+       server_lpr = merged_lpr;
+success:
+       daemon_set_loglevel(ENUM_STRING_VAL(LOGLEVEL));
+       if (OPT_GIVEN(LOGFILE)) {
+               daemon_set_logfile(OPT_STRING_VAL(LOGFILE));
+               daemon_open_log_or_die();
+       }
+       if (daemon_init_colors_or_die(OPT_UINT32_VAL(COLOR), COLOR_AUTO,
+                       COLOR_NO, OPT_GIVEN(LOGFILE))) {
+               int i;
+               for (i = 0; i < OPT_GIVEN(LOG_COLOR); i++)
+                       daemon_set_log_color_or_die(lls_string_val(i,
+                               OPT_RESULT(LOG_COLOR)));
        }
-       if (conf.logfile_given)
-               logfile = open_log(conf.logfile_arg);
+       daemon_set_flag(DF_LOG_PID);
+       daemon_set_flag(DF_LOG_LL);
+       daemon_set_flag(DF_LOG_TIME);
+       if (OPT_GIVEN(LOG_TIMING))
+               daemon_set_flag(DF_LOG_TIMING);
+       daemon_set_priority(OPT_UINT32_VAL(PRIORITY));
+       if (user_list_file)
+               user_list_init(user_list_file);
        ret = 1;
-out:
+free_cf:
        free(cf);
-       free(home);
-       if (ret > 0)
-               return;
        free(user_list_file);
-       user_list_file = NULL;
-       exit(EXIT_FAILURE);
+       if (ret < 0) {
+               if (errctx)
+                       PARA_ERROR_LOG("%s\n", errctx);
+               free(errctx);
+               PARA_EMERG_LOG("%s\n", para_strerror(-ret));
+               exit(EXIT_FAILURE);
+       }
 }
 
-static void setup_signal_handling(void)
+/*
+ * called when server gets SIGHUP or when client invokes hup command.
+ */
+static void handle_sighup(void)
 {
-       int ret = 0;
-
-       signal_pipe = para_signal_init();
-       PARA_NOTICE_LOG("%s", "setting up signal handlers\n");
-       ret += para_install_sighandler(SIGINT);
-       ret += para_install_sighandler(SIGTERM);
-       ret += para_install_sighandler(SIGHUP);
-       ret += para_install_sighandler(SIGCHLD);
-       ret += para_install_sighandler(SIGUSR1);
-       signal(SIGPIPE, SIG_IGN);
-       if (ret != 5) {
-               PARA_EMERG_LOG("%s", "could not install signal handlers\n");
-               exit(EXIT_FAILURE);
-       }
+
+       PARA_NOTICE_LOG("SIGHUP\n");
+       parse_config_or_die(true);
+       if (afs_pid != 0)
+               kill(afs_pid, SIGHUP);
 }
 
-static unsigned init_network(void)
+static int signal_post_select(struct sched *s, __a_unused void *context)
 {
-       int fd, ret = init_tcp_socket(conf.port_arg);
+       int ret, signum;
 
+       ret = task_get_notification(signal_task->task);
        if (ret < 0)
-               goto err;
-       fd = ret;
-       ret = mark_fd_nonblock(fd);
-       if (ret < 0)
-               goto err;
-       return fd;
-err:
-       PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
-       exit(EXIT_FAILURE);
+               return ret;
+       signum = para_next_signal(&s->rfds);
+       switch (signum) {
+       case 0:
+               return 0;
+       case SIGHUP:
+               handle_sighup();
+               break;
+       case SIGCHLD:
+               for (;;) {
+                       pid_t pid;
+                       ret = para_reap_child(&pid);
+                       if (ret <= 0)
+                               break;
+                       if (pid != afs_pid)
+                               continue;
+                       PARA_EMERG_LOG("fatal: afs died\n");
+                       kill(0, SIGTERM);
+                       goto cleanup;
+               }
+               break;
+       /* die on sigint/sigterm. Kill all children too. */
+       case SIGINT:
+       case SIGTERM:
+               PARA_EMERG_LOG("terminating on signal %d\n", signum);
+               kill(0, SIGTERM);
+               /*
+                * We must wait for all of our children to die. For the afs
+                * process or a command handler might want to use the
+                * shared memory area and the mmd mutex.  If we destroy this
+                * mutex too early and afs tries to lock the shared memory
+                * area, the call to mutex_lock() will fail and terminate the
+                * afs process. This leads to dirty osl tables.
+                */
+               PARA_INFO_LOG("waiting for child processes to die\n");
+               mutex_unlock(mmd_mutex);
+               while (wait(NULL) != -1 || errno != ECHILD)
+                       ; /* still at least one child alive */
+               mutex_lock(mmd_mutex);
+cleanup:
+               free(mmd->afd.afhi.chunk_table);
+               task_notify_all(s, E_DEADLY_SIGNAL);
+               return -E_DEADLY_SIGNAL;
+       }
+       return 0;
+}
+
+static void init_signal_task(void)
+{
+       signal_task = signal_init_or_die();
+       para_install_sighandler(SIGINT);
+       para_install_sighandler(SIGTERM);
+       para_install_sighandler(SIGHUP);
+       para_install_sighandler(SIGCHLD);
+       para_sigaction(SIGPIPE, SIG_IGN);
+       add_close_on_fork_list(signal_task->fd);
+       signal_task->task = task_register(&(struct task_info) {
+               .name = "signal",
+               .pre_select = signal_pre_select,
+               .post_select = signal_post_select,
+               .context = signal_task,
+
+       }, &sched);
 }
 
-static void init_random_seed(void)
+static void command_pre_select(struct sched *s, void *context)
 {
-       int fd, ret = -1;
-       unsigned int seed;
-       size_t len = sizeof(unsigned int);
+       struct server_command_task *sct = context;
+       para_fd_set(sct->listen_fd, &s->rfds, &s->max_fileno);
+}
 
-       fd = open("/dev/urandom", O_RDONLY);
-       if (fd < 0)
+static int command_post_select(struct sched *s, void *context)
+{
+       struct server_command_task *sct = context;
+       int new_fd, ret, i;
+       char *peer_name;
+       pid_t child_pid;
+       uint32_t *chunk_table;
+
+       ret = task_get_notification(sct->task);
+       if (ret < 0)
+               return ret;
+       ret = para_accept(sct->listen_fd, &s->rfds, NULL, 0, &new_fd);
+       if (ret <= 0)
                goto out;
-       ret = -2;
-       if (read(fd, &seed, len) != len)
+       mmd->num_connects++;
+       mmd->active_connections++;
+       /*
+        * The chunk table is a pointer located in the mmd struct that points
+        * to dynamically allocated memory, i.e. it must be freed by the parent
+        * and the child. However, as the mmd struct is in a shared memory
+        * area, there's no guarantee that after the fork this pointer is still
+        * valid in child context. As it is not used in the child anyway, we
+        * save it to a local variable before the fork and free the memory via
+        * that copy in the child directly after the fork.
+        */
+       chunk_table = mmd->afd.afhi.chunk_table;
+       child_pid = fork();
+       if (child_pid < 0) {
+               ret = -ERRNO_TO_PARA_ERROR(errno);
                goto out;
-       srandom(seed);
-       ret = 1;
+       }
+       if (child_pid) {
+               /* avoid problems with non-fork-safe PRNGs */
+               unsigned char buf[16];
+               get_random_bytes_or_die(buf, sizeof(buf));
+               close(new_fd);
+               /* parent keeps accepting connections */
+               return 0;
+       }
+       peer_name = remote_name(new_fd);
+       PARA_INFO_LOG("accepted connection from %s\n", peer_name);
+       /* mmd might already have changed at this point */
+       free(chunk_table);
+       sct->child_fd = new_fd;
+       /*
+        * put info on who we are serving into argv[0] to make
+        * client ip visible in top/ps
+        */
+       for (i = sct->argc - 1; i >= 0; i--)
+               memset(sct->argv[i], 0, strlen(sct->argv[i]));
+       i = sct->argc - 1 - lls_num_inputs(cmdline_lpr);
+       sprintf(sct->argv[i], "para_server (serving %s)", peer_name);
+       /* ask other tasks to terminate */
+       task_notify_all(s, E_CHILD_CONTEXT);
+       /*
+        * After we return, the scheduler calls server_select() with a minimal
+        * timeout value, because the remaining tasks have a notification
+        * pending. Next it calls the ->post_select method of these tasks,
+        * which will return negative in view of the notification. This causes
+        * schedule() to return as there are no more runnable tasks.
+        *
+        * Note that semaphores are not inherited across a fork(), so we don't
+        * hold the lock at this point. Since server_select() drops the lock
+        * prior to calling para_select(), we need to acquire it here.
+        */
+       mutex_lock(mmd_mutex);
+       return -E_CHILD_CONTEXT;
 out:
-       if (fd >= 0)
-               close(fd);
-       if (ret > 0)
-               return;
-       PARA_EMERG_LOG("can not seed pseudo random generator (ret = %d)\n",
-               ret);
-       exit(EXIT_FAILURE);
+       if (ret < 0)
+               PARA_CRIT_LOG("%s\n", para_strerror(-ret));
+       return 0;
 }
 
-uint32_t afs_socket_cookie;
-int afs_socket;
-static pid_t afs_pid;
+static void init_server_command_task(struct server_command_task *sct,
+               int argc, char **argv)
+{
+       int ret;
 
-static void init_afs(void)
+       PARA_NOTICE_LOG("initializing tcp command socket\n");
+       sct->child_fd = -1;
+       sct->argc = argc;
+       sct->argv = argv;
+       ret = para_listen_simple(IPPROTO_TCP, OPT_UINT32_VAL(PORT));
+       if (ret < 0)
+               goto err;
+       sct->listen_fd = ret;
+       ret = mark_fd_nonblocking(sct->listen_fd);
+       if (ret < 0)
+               goto err;
+       add_close_on_fork_list(sct->listen_fd); /* child doesn't need the listener */
+       sct->task = task_register(&(struct task_info) {
+               .name = "server command",
+               .pre_select = command_pre_select,
+               .post_select = command_post_select,
+               .context = sct,
+       }, &sched);
+       return;
+err:
+       PARA_EMERG_LOG("%s\n", para_strerror(-ret));
+       exit(EXIT_FAILURE);
+}
+
+static int init_afs(int argc, char **argv)
 {
        int ret, afs_server_socket[2];
+       char c;
 
-       ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket);
+       ret = socketpair(PF_UNIX, SOCK_STREAM, 0, afs_server_socket);
        if (ret < 0)
                exit(EXIT_FAILURE);
-       afs_socket_cookie = para_random((uint32_t)-1);
+       get_random_bytes_or_die((unsigned char *)&afs_socket_cookie,
+               sizeof(afs_socket_cookie));
        afs_pid = fork();
        if (afs_pid < 0)
                exit(EXIT_FAILURE);
-       if (!afs_pid) { /* child (afs) */
+       if (afs_pid == 0) { /* child (afs) */
+               int i;
+
+               afs_pid = getpid();
+               crypt_shutdown();
+               user_list_deplete();
+               for (i = argc - 1; i >= 0; i--)
+                       memset(argv[i], 0, strlen(argv[i]));
+               i = argc - lls_num_inputs(cmdline_lpr) - 1;
+               sprintf(argv[i], "para_server (afs)");
                close(afs_server_socket[0]);
-               afs_init(afs_socket_cookie, afs_server_socket[1]);
+               afs_init(afs_server_socket[1]);
        }
        close(afs_server_socket[1]);
-       afs_socket = afs_server_socket[0];
-       ret = mark_fd_nonblock(afs_socket);
+       if (read(afs_server_socket[0], &c, 1) <= 0) {
+               PARA_EMERG_LOG("early afs exit\n");
+               exit(EXIT_FAILURE);
+       }
+       ret = mark_fd_nonblocking(afs_server_socket[0]);
        if (ret < 0)
                exit(EXIT_FAILURE);
-       add_close_on_fork_list(afs_socket);
-       PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n", afs_socket,
-               (unsigned) afs_socket_cookie);
+       add_close_on_fork_list(afs_server_socket[0]);
+       PARA_INFO_LOG("afs_socket: %d, afs_socket_cookie: %u\n",
+               afs_server_socket[0], (unsigned) afs_socket_cookie);
+       return afs_server_socket[0];
 }
 
+static void handle_help_flags(void)
+{
+       char *help;
+       bool d = OPT_GIVEN(DETAILED_HELP);
+
+       if (d)
+               help = lls_long_help(CMD_PTR);
+       else if (OPT_GIVEN(HELP))
+               help = lls_short_help(CMD_PTR);
+       else
+               return;
+       printf("%s\n", help);
+       free(help);
+       exit(EXIT_SUCCESS);
+}
 
-static unsigned do_inits(int argc, char **argv)
+static void server_init(int argc, char **argv, struct server_command_task *sct)
 {
-       /* connector's address information */
-       int sockfd;
+       int ret, afs_socket, daemon_pipe = -1;
+       char *errctx;
 
-       init_random_seed();
+       valid_fd_012();
        /* parse command line options */
-       server_cmdline_parser(argc, argv, &conf);
-       HANDLE_VERSION_FLAG("server", conf);
-       para_drop_privileges(conf.user_arg, conf.group_arg);
-       /* parse config file, open log and set defaults */
-       parse_config(0);
-       log_welcome("para_server", conf.loglevel_arg);
-       shm_init(); /* init mmd struct */
-       server_uptime(UPTIME_SET); /* reset server uptime */
-       init_user_list(user_list_file);
+       ret = lls(lls_parse(argc, argv, CMD_PTR, &cmdline_lpr, &errctx));
+       if (ret < 0)
+               goto fail;
+       server_lpr = cmdline_lpr;
+       daemon_set_loglevel(ENUM_STRING_VAL(LOGLEVEL));
+       daemon_drop_privileges_or_die(OPT_STRING_VAL(USER),
+               OPT_STRING_VAL(GROUP));
+       version_handle_flag("server", OPT_GIVEN(VERSION));
+       handle_help_flags();
+       parse_config_or_die(false);
        /* become daemon */
-       if (conf.daemon_given)
-               daemon_init();
-       PARA_NOTICE_LOG("%s", "initializing virtual streaming system\n");
+       if (OPT_GIVEN(DAEMON))
+               daemon_pipe = daemonize(true /* parent waits for SIGTERM */);
+       server_pid = getpid();
+       crypt_init();
+       daemon_log_welcome("server");
+       init_ipc_or_die(); /* init mmd struct, mmd and log mutex */
+       daemon_set_start_time();
+       daemon_set_hooks(pre_log_hook, post_log_hook);
+       PARA_NOTICE_LOG("initializing audio format handlers\n");
        afh_init();
-       vss_init();
-       mmd->server_pid = getpid();
-       setup_signal_handling();
-       init_afs();
-       mmd_lock();
-       /* init network socket */
-       PARA_NOTICE_LOG("%s", "initializing tcp command socket\n");
-       sockfd = init_network();
-       PARA_NOTICE_LOG("%s", "init complete\n");
-       return sockfd;
-}
 
-/*
- * called when server gets SIGHUP or when client invokes hup command.
- */
-static void handle_sighup(void)
-{
-       PARA_NOTICE_LOG("%s", "SIGHUP\n");
-       close_log(logfile); /* gets reopened if necessary by parse_config */
-       logfile = NULL;
-       parse_config(1); /* reopens log */
-       init_user_list(user_list_file); /* reload user list */
-       if (afs_pid)
-               kill(afs_pid, SIGHUP);
+       /*
+        * Although afs uses its own signal handling we must ignore SIGUSR1
+        * _before_ the afs child process gets born by init_afs() below.  It's
+        * racy to do this in the child because the parent might send SIGUSR1
+        * before the child gets a chance to ignore this signal.
+        *
+        * We also have to block SIGCHLD before the afs process is created
+        * because otherwise para_server does not notice if afs dies before the
+        * SIGCHLD handler has been installed for the parent process by
+        * init_signal_task() below.
+        */
+       para_sigaction(SIGUSR1, SIG_IGN);
+       para_block_signal(SIGCHLD);
+       PARA_NOTICE_LOG("initializing the audio file selector\n");
+       afs_socket = init_afs(argc, argv);
+       init_signal_task();
+       para_unblock_signal(SIGCHLD);
+       PARA_NOTICE_LOG("initializing virtual streaming system\n");
+       vss_init(afs_socket, &sched);
+       init_server_command_task(sct, argc, argv);
+       if (daemon_pipe >= 0) {
+               if (write(daemon_pipe, "\0", 1) < 0) {
+                       PARA_EMERG_LOG("daemon_pipe: %s", strerror(errno));
+                       exit(EXIT_FAILURE);
+               }
+               close(daemon_pipe);
+       }
+       PARA_NOTICE_LOG("server init complete\n");
+       return;
+fail:
+       assert(ret < 0);
+       if (errctx)
+               PARA_ERROR_LOG("%s\n", errctx);
+       PARA_EMERG_LOG("%s\n", para_strerror(-ret));
+       exit(EXIT_FAILURE);
 }
 
 static void status_refresh(void)
 {
        static int prev_uptime = -1, prev_events = -1;
-       int uptime = server_uptime(UPTIME_GET), ret = 1;
+       int uptime = daemon_get_uptime(now);
 
        if (prev_events != mmd->events)
                goto out;
        if (mmd->new_vss_status_flags != mmd->vss_status_flags)
-               goto out;
+               goto out_inc_events;
        if (uptime / 60 != prev_uptime / 60)
-               goto out;
-       ret = 0;
+               goto out_inc_events;
+       return;
+out_inc_events:
+       mmd->events++;
 out:
        prev_uptime = uptime;
        prev_events = mmd->events;
        mmd->vss_status_flags = mmd->new_vss_status_flags;
-       if (ret) {
-               PARA_DEBUG_LOG("%d events, forcing status update\n",
-                       mmd->events);
-               killpg(0, SIGUSR1);
-       }
+       PARA_DEBUG_LOG("%u events, forcing status update\n", mmd->events);
+       killpg(0, SIGUSR1);
+}
+
+static int server_select(int max_fileno, fd_set *readfds, fd_set *writefds,
+               struct timeval *timeout_tv)
+{
+       int ret;
+
+       status_refresh();
+       mutex_unlock(mmd_mutex);
+       ret = para_select(max_fileno + 1, readfds, writefds, timeout_tv);
+       mutex_lock(mmd_mutex);
+       return ret;
 }
 
 /**
- * the main function of para_server
+ * Deallocate all lopsub parse results.
  *
- * \param argc usual argument count
- * \param argv usual argument vector
+ * The server allocates a parse result for command line options and optionally
+ * a second parse result for the effective configuration, defined by merging
+ * the command line options with the options stored in the configuration file.
+ * This function frees both structures.
+ */
+void free_lpr(void)
+{
+       lls_free_parse_result(server_lpr, CMD_PTR);
+       if (server_lpr != cmdline_lpr)
+               lls_free_parse_result(cmdline_lpr, CMD_PTR);
+}
+
+/**
+ * The main function of para_server.
  *
- * \return EXIT_SUCCESS or EXIT_FAILURE
+ * \param argc Usual argument count.
+ * \param argv Usual argument vector.
  *
+ * \return EXIT_SUCCESS or EXIT_FAILURE.
  */
 int main(int argc, char *argv[])
 {
-       /* listen on sock_fd, new connection on new_fd */
-       int sockfd, new_fd;
-       struct sockaddr_in their_addr;
-       int i, max_fileno, ret;
-       pid_t chld_pid;
-       fd_set rfds, wfds;
-       struct timeval *timeout;
-
-       valid_fd_012();
-       sockfd = do_inits(argc, argv);
-repeat:
-       FD_ZERO(&rfds);
-       FD_ZERO(&wfds);
-       max_fileno = -1;
-       /* check socket and signal pipe in any case */
-       para_fd_set(sockfd, &rfds, &max_fileno);
-       para_fd_set(signal_pipe, &rfds, &max_fileno);
-       timeout = vss_preselect(&rfds, &wfds, &max_fileno);
-       status_refresh();
-       for (i = 0; senders[i].name; i++) {
-               if (senders[i].status != SENDER_ON)
-                       continue;
-               if (!senders[i].pre_select)
-                       continue;
-               senders[i].pre_select(&max_fileno, &rfds, &wfds);
-       }
-       mmd_unlock();
-       ret = para_select(max_fileno + 1, &rfds, &wfds, timeout);
-       mmd_lock();
-       vss_post_select(&rfds, &wfds);
-       if (ret < 0)
-               goto repeat;
-       for (i = 0; senders[i].name; i++) {
-               if (senders[i].status != SENDER_ON)
-                       continue;
-               if (!senders[i].post_select)
-                       continue;
-               senders[i].post_select(&rfds, &wfds);
-       }
-       vss_send_chunk();
-       status_refresh();
-       if (FD_ISSET(signal_pipe, &rfds)) {
-               int sig;
-               pid_t pid;
-               sig = para_next_signal();
-               switch (sig) {
-               case SIGHUP:
-                       handle_sighup();
-                       break;
-               case SIGCHLD:
-                       for (;;) {
-                               ret = para_reap_child(&pid);
-                               if (ret <= 0)
-                                       break;
-                               if (pid != afs_pid)
-                                       continue;
-                               PARA_EMERG_LOG("fatal: afs died\n");
-                               goto genocide;
-                       }
-                       break;
-               /* die on sigint/sigterm. Kill all children too. */
-               case SIGINT:
-               case SIGTERM:
-                       PARA_EMERG_LOG("terminating on signal %d\n", sig);
-genocide:
-                       kill(0, SIGTERM);
-                       mutex_destroy(mmd_mutex);
-                       shm_detach(mmd);
-                       shm_destroy(mmd_shm_id);
+       int ret;
+       struct server_command_task server_command_task_struct,
+               *sct = &server_command_task_struct;
 
-                       exit(EXIT_FAILURE);
-               }
-       }
-       if (mmd->sender_cmd_data.cmd_num >= 0) {
-               int num = mmd->sender_cmd_data.cmd_num,
-                       s = mmd->sender_cmd_data.sender_num;
+       sched.default_timeout.tv_sec = 1;
+       sched.select_function = server_select;
 
-               if (senders[s].client_cmds[num])
-                       senders[s].client_cmds[num](&mmd->sender_cmd_data);
-               mmd->sender_cmd_data.cmd_num = -1;
-       }
-       if (!FD_ISSET(sockfd, &rfds))
-               goto repeat;
-
-       new_fd = para_accept(sockfd, &their_addr, sizeof(struct sockaddr_in));
-       if (new_fd < 0)
-               goto repeat;
-       PARA_INFO_LOG("got connection from %s, forking\n",
-               inet_ntoa(their_addr.sin_addr));
-       mmd->num_connects++;
-       mmd->active_connections++;
-       random();
-       chld_pid = fork();
-       if (chld_pid < 0) {
-               PARA_CRIT_LOG("%s", "fork failed\n");
-               goto repeat;
-       }
-       if (chld_pid) {
-               close(new_fd);
-               /* parent keeps accepting connections */
-               goto repeat;
-       }
-       alarm(ALARM_TIMEOUT);
-       close_listed_fds();
-       close(sockfd); /* child doesn't need the listener */
+       server_init(argc, argv, sct);
+       mutex_lock(mmd_mutex);
+       ret = schedule(&sched);
        /*
-        * put info on who we are serving into argv[0] to make
-        * client ip visible in top/ps
+        * We hold the mmd lock: it was re-acquired in server_select()
+        * after the select call.
         */
-       for (i = argc - 1; i >= 0; i--)
-               memset(argv[i], 0, strlen(argv[i]));
-       sprintf(argv[0], "para_server (serving %s)",
-               inet_ntoa(their_addr.sin_addr));
-       return handle_connect(new_fd, &their_addr);
+       mutex_unlock(mmd_mutex);
+       sched_shutdown(&sched);
+       crypt_shutdown();
+       signal_shutdown(signal_task);
+       if (!process_is_command_handler()) { /* parent (server) */
+               mutex_destroy(mmd_mutex);
+               daemon_set_hooks(NULL, NULL); /* only one process remaining */
+               mutex_destroy(log_mutex);
+               deplete_close_on_fork_list();
+               if (ret < 0)
+                       PARA_EMERG_LOG("%s\n", para_strerror(-ret));
+       } else {
+               alarm(ALARM_TIMEOUT);
+               close_listed_fds();
+               ret = handle_connect(sct->child_fd);
+       }
+       vss_shutdown();
+       shm_detach(mmd);
+       user_list_deplete();
+       free_lpr();
+       exit(ret < 0? EXIT_FAILURE : EXIT_SUCCESS);
 }