-/*
- * Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
+/* Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
/** \file command.c Client authentication and server commands. */
#include <netdb.h>
#include <lopsub.h>
+#include "server.lsg.h"
#include "para.h"
#include "error.h"
#include "crypt.h"
#include "sideband.h"
#include "command.h"
-#include "server.cmdline.h"
#include "string.h"
#include "afh.h"
#include "afs.h"
#include "ipc.h"
#include "server_cmd.lsg.h"
#include "user_list.h"
-#include "afs.command_list.h"
#include "signal.h"
#include "version.h"
static const char * const server_command_perms_txt[] = {LSG_SERVER_CMD_AUX_INFOS};
#undef SERVER_CMD_AUX_INFO
-typedef int server_command_handler_t(struct command_context *);
-server_command_handler_t AFS_COMMAND_HANDLERS;
-
-/* Defines one command of para_server. */
-struct server_command {
- /* The name of the command. */
- const char *name;
- /* Pointer to the function that handles the command. */
- server_command_handler_t *handler;
- /* The privileges a user must have to execute this command. */
- unsigned int perms;
- /* One-line description of the command. */
- const char *description;
- /* Summary of the command line options. */
- const char *usage;
- /* The long help text. */
- const char *help;
-};
-
-static struct server_command afs_cmds[] = {DEFINE_AFS_CMD_ARRAY};
-
/** Commands including options must be shorter than this. */
#define MAX_COMMAND_LEN 32768
extern int mmd_mutex;
extern struct misc_meta_data *mmd;
-extern struct sender senders[];
int send_afs_status(struct command_context *cc, int parser_friendly);
+static bool subcmd_should_die;
-static void dummy(__a_unused int s)
+static void command_handler_sighandler(int s)
{
+ if (s != SIGTERM)
+ return;
+ PARA_EMERG_LOG("terminating on signal %d\n", SIGTERM);
+ subcmd_should_die = true;
}
/*
clock_get_realtime(¤t_time);
/*
* The calls to WRITE_STATUS_ITEM() below never fail because
- * b->max_size is zero (unlimited), see para_printf(). However, clang
- * is not smart enough to prove this and complains nevertheless.
+ * b->max_size is zero (unlimited), see \ref para_printf(). However,
+ * clang is not smart enough to prove this and complains nevertheless.
* Casting the return value to void silences clang.
*/
- (void)WRITE_STATUS_ITEM(&b, SI_STATUS, "%s\n", status);
- (void)WRITE_STATUS_ITEM(&b, SI_STATUS_FLAGS, "%s\n", flags);
- (void)WRITE_STATUS_ITEM(&b, SI_OFFSET, "%li\n", offset);
- (void)WRITE_STATUS_ITEM(&b, SI_AFS_MODE, "%s\n", mmd->afs_mode_string);
- (void)WRITE_STATUS_ITEM(&b, SI_STREAM_START, "%lu.%lu\n",
+ (void)WRITE_STATUS_ITEM(&b, SI_status, "%s\n", status);
+ (void)WRITE_STATUS_ITEM(&b, SI_status_flags, "%s\n", flags);
+ (void)WRITE_STATUS_ITEM(&b, SI_offset, "%li\n", offset);
+ (void)WRITE_STATUS_ITEM(&b, SI_afs_mode, "%s\n", mmd->afs_mode_string);
+ (void)WRITE_STATUS_ITEM(&b, SI_stream_start, "%lu.%lu\n",
(long unsigned)nmmd->stream_start.tv_sec,
(long unsigned)nmmd->stream_start.tv_usec);
- (void)WRITE_STATUS_ITEM(&b, SI_CURRENT_TIME, "%lu.%lu\n",
+ (void)WRITE_STATUS_ITEM(&b, SI_current_time, "%lu.%lu\n",
(long unsigned)current_time.tv_sec,
(long unsigned)current_time.tv_usec);
free(flags);
struct lls_parse_result *lpr, struct sender_command_data *scd)
{
int i, ret;
- const char *subcmds[] = {SENDER_SUBCOMMANDS};
+ const char * const subcmds[] = {SENDER_SUBCOMMANDS};
const char *arg;
char *errctx;
unsigned num_inputs = lls_num_inputs(lpr);
return ret;
}
arg = lls_input(0, lpr);
- for (i = 0; senders[i].name; i++)
- if (!strcmp(senders[i].name, arg))
+ FOR_EACH_SENDER(i)
+ if (strcmp(senders[i]->name, arg) == 0)
break;
- if (!senders[i].name)
+ if (!senders[i])
return -E_COMMAND_SYNTAX;
scd->sender_num = i;
arg = lls_input(1, lpr);
- for (i = 0; subcmds[i]; i++)
+ for (i = 0; i < NUM_SENDER_CMDS; i++)
if (!strcmp(subcmds[i], arg))
break;
- if (!subcmds[i])
+ if (i == NUM_SENDER_CMDS)
return -E_COMMAND_SYNTAX;
scd->cmd_num = i;
- if (!senders[scd->sender_num].client_cmds[scd->cmd_num])
+ if (!senders[scd->sender_num]->client_cmds[scd->cmd_num])
return -E_SENDER_CMD;
switch (scd->cmd_num) {
case SENDER_on:
struct sender_command_data scd;
if (lls_num_inputs(lpr) == 0) {
- for (i = 0; senders[i].name; i++) {
+ FOR_EACH_SENDER(i) {
char *tmp;
ret = xasprintf(&tmp, "%s%s\n", msg? msg : "",
- senders[i].name);
+ senders[i]->name);
free(msg);
msg = tmp;
}
if (scd.sender_num < 0)
return ret;
if (strcmp(lls_input(1, lpr), "status") == 0)
- msg = senders[scd.sender_num].status();
+ msg = senders[scd.sender_num]->status();
else
- msg = senders[scd.sender_num].help();
+ msg = senders[scd.sender_num]->help();
return send_sb(&cc->scc, msg, strlen(msg), SBD_OUTPUT, false);
}
switch (scd.cmd_num) {
case SENDER_add:
case SENDER_delete:
- assert(senders[scd.sender_num].resolve_target);
- ret = senders[scd.sender_num].resolve_target(lls_input(2, lpr),
+ assert(senders[scd.sender_num]->resolve_target);
+ ret = senders[scd.sender_num]->resolve_target(lls_input(2, lpr),
&scd);
if (ret < 0)
return ret;
"supported audio formats: %s\n",
ut, mmd->num_played,
(int)getppid(),
- (int)mmd->afs_pid,
+ (int)afs_pid,
mmd->active_connections,
mmd->num_commands,
mmd->num_connects,
- conf.loglevel_arg,
+ ENUM_STRING_VAL(LOGLEVEL),
AUDIO_FORMAT_HANDLERS
);
mutex_unlock(mmd_mutex);
/** These status items are cleared if no audio file is currently open. */
#define EMPTY_STATUS_ITEMS \
- ITEM(PATH) \
- ITEM(DIRECTORY) \
- ITEM(BASENAME) \
- ITEM(SCORE) \
- ITEM(ATTRIBUTES_BITMAP) \
- ITEM(ATTRIBUTES_TXT) \
- ITEM(HASH) \
- ITEM(IMAGE_ID) \
- ITEM(IMAGE_NAME) \
- ITEM(LYRICS_ID) \
- ITEM(LYRICS_NAME) \
- ITEM(BITRATE) \
- ITEM(FORMAT) \
- ITEM(FREQUENCY) \
- ITEM(CHANNELS) \
- ITEM(DURATION) \
- ITEM(SECONDS_TOTAL) \
- ITEM(NUM_PLAYED) \
- ITEM(LAST_PLAYED) \
- ITEM(TECHINFO) \
- ITEM(ARTIST) \
- ITEM(TITLE) \
- ITEM(YEAR) \
- ITEM(ALBUM) \
- ITEM(COMMENT) \
- ITEM(MTIME) \
- ITEM(FILE_SIZE) \
- ITEM(CHUNK_TIME) \
- ITEM(NUM_CHUNKS) \
- ITEM(AMPLIFICATION) \
+ ITEM(path) \
+ ITEM(directory) \
+ ITEM(basename) \
+ ITEM(score) \
+ ITEM(attributes_bitmap) \
+ ITEM(attributes_txt) \
+ ITEM(hash) \
+ ITEM(image_id) \
+ ITEM(image_name) \
+ ITEM(lyrics_id) \
+ ITEM(lyrics_name) \
+ ITEM(bitrate) \
+ ITEM(format) \
+ ITEM(frequency) \
+ ITEM(channels) \
+ ITEM(duration) \
+ ITEM(seconds_total) \
+ ITEM(num_played) \
+ ITEM(last_played) \
+ ITEM(techinfo) \
+ ITEM(artist) \
+ ITEM(title) \
+ ITEM(year) \
+ ITEM(album) \
+ ITEM(comment) \
+ ITEM(mtime) \
+ ITEM(file_size) \
+ ITEM(chunk_time) \
+ ITEM(num_chunks) \
+ ITEM(amplification) \
-/**
- * Write a list of audio-file related status items with empty values.
- *
- * This is used by vss when currently no audio file is open.
+/*
+ * Create a set of audio-file related status items with empty values. These are
+ * written to stat clients when no audio file is open.
*/
static unsigned empty_status_items(bool parser_friendly, char **result)
{
bool parser_friendly = SERVER_CMD_OPT_GIVEN(STAT, PARSER_FRIENDLY,
lpr) > 0;
uint32_t num = SERVER_CMD_UINT32_VAL(STAT, NUM, lpr);
+ const struct timespec ts = {.tv_sec = 50, .tv_nsec = 0};
- para_sigaction(SIGUSR1, dummy);
+ para_sigaction(SIGINT, SIG_IGN);
+ para_sigaction(SIGUSR1, command_handler_sighandler);
+ para_sigaction(SIGTERM, command_handler_sighandler);
+ /*
+ * Simply checking subcmd_should_die is racy because a signal may
+ * arrive after the check but before the subsequent call to sleep(3).
+ * If this happens, sleep(3) would not be interrupted by the signal.
+ * To avoid this we block SIGTERM here and allow it to arrive only
+ * while we sleep.
+ */
+ para_block_signal(SIGTERM);
for (;;) {
+ sigset_t set;
/*
* Copy the mmd structure to minimize the time we hold the mmd
* lock.
ret = 1;
if (num > 0 && !--num)
goto out;
- sleep(50);
+ sigemptyset(&set); /* empty set means: unblock all signals */
+ /*
+ * pselect(2) allows to atomically unblock signals, then go to
+ * sleep. Calling sigprocmask(2) followed by sleep(3) would
+ * open a race window similar to the one described above.
+ */
+ pselect(1, NULL, NULL, NULL, &ts, &set);
+ if (subcmd_should_die)
+ goto out;
ret = -E_SERVER_CRASH;
if (getppid() == 1)
goto out;
return send_sb(&cc->scc, msg, strlen(msg), SBD_OUTPUT, false);
}
-/* returns string that must be freed by the caller */
-static struct server_command *get_cmd_ptr(const char *name, char **handler)
-{
- struct server_command *cmd;
-
- /* not found, look for commands supported by afs */
- for (cmd = afs_cmds; cmd->name; cmd++)
- if (!strcmp(cmd->name, name)) {
- if (handler)
- *handler = para_strdup("afs");
- return cmd;
- }
- return NULL;
-}
-
static int com_help(struct command_context *cc, struct lls_parse_result *lpr)
{
const char *perms;
}
EXPORT_SERVER_CMD_HANDLER(jmp);
-static int com_tasks(struct command_context *cc,
+/* deprecated, does nothing */
+static int com_tasks(__a_unused struct command_context *cc,
__a_unused struct lls_parse_result *lpr)
{
- char *tl = server_get_tasks();
- assert(tl);
- return send_sb(&cc->scc, tl, strlen(tl), SBD_OUTPUT, false);
+ return 1;
}
EXPORT_SERVER_CMD_HANDLER(tasks);
-/*
- * check if perms are sufficient to exec a command having perms cmd_perms.
- * Returns 0 if perms are sufficient, -E_PERM otherwise.
- */
-static int check_perms(unsigned int perms, const struct server_command *cmd_ptr)
-{
- PARA_DEBUG_LOG("checking permissions\n");
- return (cmd_ptr->perms & perms) < cmd_ptr->perms ? -E_PERM : 0;
-}
-
static void reset_signals(void)
{
para_sigaction(SIGCHLD, SIG_IGN);
}
struct connection_features {
- bool aes_ctr128_requested;
+ int dummy; /* none at the moment */
};
-static int parse_auth_request(char *buf, int len, struct user **u,
+static int parse_auth_request(char *buf, int len, const struct user **u,
struct connection_features *cf)
{
int ret;
if (strcmp(features[i], "sideband") == 0)
continue;
if (strcmp(features[i], "aes_ctr128") == 0)
- cf->aes_ctr128_requested = true;
+ continue;
else {
ret = -E_BAD_FEATURE;
goto out;
}
}
PARA_DEBUG_LOG("received auth request for user %s\n", username);
- *u = lookup_user(username);
+ *u = user_list_lookup(username);
ret = 1;
out:
free_argv(features);
#define HANDSHAKE_BUFSIZE 4096
-static int run_command(struct command_context *cc, struct iovec *iov,
- const char *peername)
+static int run_command(struct command_context *cc, struct iovec *iov)
{
- int ret, i;
- char *p, *end;
- struct server_command *cmd = NULL;
+ int ret, i, argc;
+ char *p, *end, **argv;
const struct lls_command *lcmd = NULL;
unsigned perms;
struct lls_parse_result *lpr;
p[iov->iov_len - 1] = '\0'; /* just to be sure */
ret = lls(lls_lookup_subcmd(p, server_cmd_suite, &errctx));
- if (ret >= 0) {
- perms = server_command_perms[ret];
- if ((perms & cc->u->perms) != perms)
- return -E_PERM;
- lcmd = lls_cmd(ret, server_cmd_suite);
- } else {
- cmd = get_cmd_ptr(p, NULL);
- if (!cmd) {
- send_errctx(cc, errctx);
- return ret;
- }
- perms = cmd->perms;
- ret = check_perms(cc->u->perms, cmd);
- if (ret < 0)
- return ret;
+ if (ret < 0) {
+ send_errctx(cc, errctx);
+ return ret;
}
+ perms = server_command_perms[ret];
+ if ((perms & cc->u->perms) != perms)
+ return -E_PERM;
+ lcmd = lls_cmd(ret, server_cmd_suite);
end = iov->iov_base + iov->iov_len;
for (i = 0; p < end; i++)
p += strlen(p) + 1;
- cc->argc = i;
- cc->argv = para_malloc((cc->argc + 1) * sizeof(char *));
+ argc = i;
+ argv = para_malloc((argc + 1) * sizeof(char *));
for (i = 0, p = iov->iov_base; p < end; i++) {
- cc->argv[i] = para_strdup(p);
+ argv[i] = para_strdup(p);
p += strlen(p) + 1;
}
- cc->argv[cc->argc] = NULL;
- PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", lcmd?
- lls_command_name(lcmd) : cmd->name, cc->u->name, peername);
- if (lcmd) {
- ret = lls(lls_parse(cc->argc, cc->argv, lcmd, &lpr, &errctx));
- if (ret >= 0) {
- const struct server_cmd_user_data *ud = lls_user_data(lcmd);
- ret = ud->handler(cc, lpr);
- lls_free_parse_result(lpr, lcmd);
- } else
- send_errctx(cc, errctx);
- } else {
- ret = cmd->handler(cc);
- }
- free_argv(cc->argv);
+ argv[argc] = NULL;
+ PARA_NOTICE_LOG("calling com_%s() for user %s\n",
+ lls_command_name(lcmd), cc->u->name);
+ ret = lls(lls_parse(argc, argv, lcmd, &lpr, &errctx));
+ if (ret >= 0) {
+ const struct server_cmd_user_data *ud = lls_user_data(lcmd);
+ ret = ud->handler(cc, lpr);
+ lls_free_parse_result(lpr, lcmd);
+ } else
+ send_errctx(cc, errctx);
+ free_argv(argv);
mutex_lock(mmd_mutex);
mmd->num_commands++;
if (ret >= 0 && (perms & AFS_WRITE))
* Perform user authentication and execute a command.
*
* \param fd The file descriptor to send output to.
- * \param peername Identifies the connecting peer.
*
* Whenever para_server accepts an incoming tcp connection on the port it
* listens on, it forks and the resulting child calls this function.
* permissions to execute that command, the function calls the corresponding
* command handler which does argument checking and further processing.
*
- * In order to cope with a DOS attacks, a timeout is set up which terminates
+ * In order to cope with DOS attacks, a timeout is set up which terminates
* the function if the connection was not authenticated when the timeout
* expires.
*
- * \sa alarm(2), crypt.c, crypt.h
+ * \sa alarm(2), \ref crypt.c, \ref crypt.h.
*/
-__noreturn void handle_connect(int fd, const char *peername)
+int handle_connect(int fd)
{
int ret;
unsigned char rand_buf[CHALLENGE_SIZE + 2 * SESSION_KEY_LEN];
unsigned char challenge_hash[HASH_SIZE];
char *command = NULL, *buf = para_malloc(HANDSHAKE_BUFSIZE) /* must be on the heap */;
size_t numbytes;
- struct command_context cc_struct = {.peer = peername}, *cc = &cc_struct;
+ struct command_context cc_struct = {.u = NULL}, *cc = &cc_struct;
struct iovec iov;
struct connection_features cf;
alarm(0);
PARA_INFO_LOG("good auth for %s\n", cc->u->name);
/* init stream cipher keys with the second part of the random buffer */
- cc->scc.recv = sc_new(rand_buf + CHALLENGE_SIZE, SESSION_KEY_LEN,
- cf.aes_ctr128_requested);
+ cc->scc.recv = sc_new(rand_buf + CHALLENGE_SIZE, SESSION_KEY_LEN);
cc->scc.send = sc_new(rand_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
- SESSION_KEY_LEN, cf.aes_ctr128_requested);
+ SESSION_KEY_LEN);
ret = send_sb(&cc->scc, NULL, 0, SBD_PROCEED, false);
if (ret < 0)
goto net_err;
ret = recv_sb(&cc->scc, SBD_COMMAND, MAX_COMMAND_LEN, &iov);
if (ret < 0)
goto net_err;
- ret = run_command(cc, &iov, peername);
+ ret = run_command(cc, &iov);
free(iov.iov_base);
if (ret < 0)
goto err_out;
}
sc_free(cc->scc.recv);
sc_free(cc->scc.send);
- exit(ret < 0? EXIT_FAILURE : EXIT_SUCCESS);
+ return ret;
}
projects / paraslash.git / blobdiff