/*
- * Copyright (C) 1997-2011 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>
*
* Licensed under the GPL v2. For licencing details see COPYING.
*/
/** \file command.c Client authentication and server commands. */
+#include <netinet/in.h>
+#include <sys/socket.h>
#include <regex.h>
#include <signal.h>
-#include <sys/time.h>
#include <sys/types.h>
#include <osl.h>
-#include <stdbool.h>
+#include <arpa/inet.h>
+#include <sys/un.h>
+#include <netdb.h>
#include "para.h"
#include "error.h"
#include "crypt.h"
+#include "sideband.h"
#include "command.h"
#include "server.cmdline.h"
#include "string.h"
#include "server.h"
#include "list.h"
#include "send.h"
+#include "sched.h"
#include "vss.h"
#include "net.h"
#include "daemon.h"
#include "fd.h"
#include "ipc.h"
#include "user_list.h"
-#include "server_command_list.h"
-#include "afs_command_list.h"
-#include "sched.h"
+#include "server.command_list.h"
+#include "afs.command_list.h"
#include "signal.h"
#include "version.h"
+typedef int server_command_handler_t(struct command_context *);
+static server_command_handler_t SERVER_COMMAND_HANDLERS;
+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};
+static struct server_command server_cmds[] = {DEFINE_SERVER_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 stream_cipher_context *scc, int parser_friendly);
-
-const char *status_item_list[] = {STATUS_ITEM_ARRAY};
+int send_afs_status(struct command_context *cc, int parser_friendly);
static void dummy(__a_unused int s)
{
return msg;
}
-static char *get_status(struct misc_meta_data *nmmd, int parser_friendly)
+static unsigned get_status(struct misc_meta_data *nmmd, int parser_friendly,
+ char **result)
{
- char mtime[30] = "";
char *status, *flags; /* vss status info */
/* nobody updates our version of "now" */
- char *ut = get_server_uptime_str(NULL);
long offset = (nmmd->offset + 500) / 1000;
struct timeval current_time;
- struct tm mtime_tm;
struct para_buffer b = {.flags = parser_friendly? PBF_SIZE_PREFIX : 0};
/* report real status */
status = vss_status_tohuman(nmmd->vss_status_flags);
flags = vss_get_status_flags(nmmd->vss_status_flags);
- if (nmmd->size) { /* parent currently has an audio file open */
- localtime_r(&nmmd->mtime, &mtime_tm);
- strftime(mtime, 29, "%b %d %Y", &mtime_tm);
- }
- gettimeofday(¤t_time, NULL);
+ 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.
- * Casting the return value to void silences solves this.
+ * Casting the return value to void silences clang.
*/
- (void)WRITE_STATUS_ITEM(&b, SI_FILE_SIZE, "%zu\n", nmmd->size / 1024);
- (void)WRITE_STATUS_ITEM(&b, SI_MTIME, "%s\n", mtime);
(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);
(long unsigned)current_time.tv_usec);
free(flags);
free(status);
- free(ut);
- return b.buf;
+ *result = b.buf;
+ return b.offset;
}
static int check_sender_args(int argc, char * const * argv, struct sender_command_data *scd)
return 1;
}
-int com_sender(struct stream_cipher_context *scc, int argc, char * const * argv)
+/**
+ * Send a sideband packet through a blocking file descriptor.
+ *
+ * \param scc fd and crypto keys.
+ * \param buf The buffer to send.
+ * \param numbytes The size of \a buf.
+ * \param band The sideband designator of this packet.
+ * \param dont_free If true, never deallocate \a buf.
+ *
+ * The nonblock flag must be disabled for the file descriptor given by \a scc.
+ *
+ * Stream cipher encryption is automatically activated if necessary via the
+ * sideband transformation, depending on the value of \a band.
+ *
+ * \return Standard.
+ *
+ * \sa \ref send_sb_va().
+ */
+int send_sb(struct stream_cipher_context *scc, void *buf, size_t numbytes,
+ int band, bool dont_free)
{
- int i, ret;
+ int ret;
+ struct sb_context *sbc;
+ struct iovec iov[2];
+ sb_transformation trafo = band < SBD_PROCEED? NULL : sc_trafo;
+ struct sb_buffer sbb = SBB_INIT(band, buf, numbytes);
+
+ sbc = sb_new_send(&sbb, dont_free, trafo, scc->send);
+ do {
+ ret = sb_get_send_buffers(sbc, iov);
+ ret = xwritev(scc->fd, iov, ret);
+ if (ret < 0)
+ goto fail;
+ } while (sb_sent(sbc, ret) == false);
+ return 1;
+fail:
+ sb_free(sbc);
+ return ret;
+}
+
+/**
+ * Create a variable sized buffer and send it as a sideband packet.
+ *
+ * \param scc Passed to \ref send_sb.
+ * \param band See \ref send_sb.
+ * \param fmt The format string.
+ *
+ * \return The return value of the underlying call to \ref send_sb.
+ */
+__printf_3_4 int send_sb_va(struct stream_cipher_context *scc, int band,
+ const char *fmt, ...)
+{
+ va_list ap;
+ char *msg;
+ int ret;
+
+ va_start(ap, fmt);
+ ret = xvasprintf(&msg, fmt, ap);
+ va_end(ap);
+ return send_sb(scc, msg, ret, band, false);
+}
+
+/**
+ * Send an error message to a client.
+ *
+ * \param cc Client info.
+ * \param err The (positive) error code.
+ *
+ * \return The return value of the underlying call to send_sb_va().
+ */
+int send_strerror(struct command_context *cc, int err)
+{
+ return send_sb_va(&cc->scc, SBD_ERROR_LOG, "%s\n", para_strerror(err));
+}
+
+/**
+ * Send a sideband packet through a blocking file descriptor.
+ *
+ * \param scc fd and crypto keys.
+ * \param expected_band The expected band designator.
+ * \param max_size Passed to \ref sb_new_recv().
+ * \param result Body of the sideband packet is returned here.
+ *
+ * If \a expected_band is not \p SBD_ANY, the band designator of the received
+ * sideband packet is compared to \a expected_band and a mismatch is considered
+ * an error.
+ *
+ * \return Standard.
+ */
+int recv_sb(struct stream_cipher_context *scc,
+ enum sb_designator expected_band,
+ size_t max_size, struct iovec *result)
+{
+ int ret;
+ struct sb_context *sbc;
+ struct iovec iov;
+ struct sb_buffer sbb;
+ sb_transformation trafo;
+
+ trafo = expected_band != SBD_ANY && expected_band < SBD_PROCEED?
+ NULL : sc_trafo;
+ sbc = sb_new_recv(max_size, trafo, scc->recv);
+ for (;;) {
+ sb_get_recv_buffer(sbc, &iov);
+ ret = recv_bin_buffer(scc->fd, iov.iov_base, iov.iov_len);
+ if (ret == 0)
+ ret = -E_EOF;
+ if (ret < 0)
+ goto fail;
+ ret = sb_received(sbc, ret, &sbb);
+ if (ret < 0)
+ goto fail;
+ if (ret > 0)
+ break;
+ }
+ ret = -E_BAD_BAND;
+ if (expected_band != SBD_ANY && sbb.band != expected_band)
+ goto fail;
+ *result = sbb.iov;
+ return 1;
+fail:
+ sb_free(sbc);
+ return ret;
+}
+
+static int com_sender(struct command_context *cc)
+{
+ int i, ret = 0;
char *msg = NULL;
struct sender_command_data scd;
- if (argc < 2) {
+ if (cc->argc < 2) {
for (i = 0; senders[i].name; i++) {
- char *tmp = make_message("%s%s\n",
- msg? msg : "", senders[i].name);
+ char *tmp;
+ ret = xasprintf(&tmp, "%s%s\n", msg? msg : "",
+ senders[i].name);
free(msg);
msg = tmp;
}
- ret = sc_send_buffer(scc, msg);
- free(msg);
- return ret;
+ return send_sb(&cc->scc, msg, ret, SBD_OUTPUT, false);
}
- ret = check_sender_args(argc, argv, &scd);
+ ret = check_sender_args(cc->argc, cc->argv, &scd);
if (ret < 0) {
if (scd.sender_num < 0)
return ret;
- msg = senders[scd.sender_num].help();
- ret = sc_send_buffer(scc, msg);
- free(msg);
- return ret;
+ if (strcmp(cc->argv[2], "status") == 0)
+ msg = senders[scd.sender_num].status();
+ else
+ 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(argv[3], &scd);
+ ret = senders[scd.sender_num].resolve_target(cc->argv[3], &scd);
if (ret < 0)
return ret;
}
for (i = 0; i < 10; i++) {
mutex_lock(mmd_mutex);
if (mmd->sender_cmd_data.cmd_num >= 0) {
+ /* another sender command is active, retry in 100ms */
+ struct timespec ts = {.tv_nsec = 100 * 1000 * 1000};
mutex_unlock(mmd_mutex);
- usleep(100 * 1000);
+ nanosleep(&ts, NULL);
continue;
}
- memcpy(&mmd->sender_cmd_data, &scd, sizeof(scd));
+ mmd->sender_cmd_data = scd;
mutex_unlock(mmd_mutex);
break;
}
}
/* server info */
-int com_si(struct stream_cipher_context *scc, int argc, __a_unused char * const * argv)
+static int com_si(struct command_context *cc)
{
- int i, ret;
- char *ut;
- char *sender_info = NULL;
+ int ret;
+ char *msg, *ut;
- if (argc != 1)
+ if (cc->argc != 1)
return -E_COMMAND_SYNTAX;
mutex_lock(mmd_mutex);
- for (i = 0; senders[i].name; i++) {
- char *info = senders[i].info();
- sender_info = para_strcat(sender_info, info);
- free(info);
- }
- ut = get_server_uptime_str(now);
- ret = sc_send_va_buffer(scc, "version: " GIT_VERSION "\n"
+ ut = daemon_get_uptime_str(now);
+ ret = xasprintf(&msg,
"up: %s\nplayed: %u\n"
"server_pid: %d\n"
"afs_pid: %d\n"
"connections (active/accepted/total): %u/%u/%u\n"
"current loglevel: %s\n"
- "supported audio formats: %s\n"
- "%s",
+ "supported audio formats: %s\n",
ut, mmd->num_played,
(int)getppid(),
(int)mmd->afs_pid,
mmd->num_commands,
mmd->num_connects,
conf.loglevel_arg,
- SERVER_AUDIO_FORMATS,
- sender_info
+ AUDIO_FORMAT_HANDLERS
);
mutex_unlock(mmd_mutex);
free(ut);
- free(sender_info);
- return ret;
+ return send_sb(&cc->scc, msg, ret, SBD_OUTPUT, false);
}
/* version */
-int com_version(struct stream_cipher_context *scc, int argc, __a_unused char * const * argv)
+static int com_version(struct command_context *cc)
{
- if (argc != 1)
- return -E_COMMAND_SYNTAX;
- return sc_send_buffer(scc, VERSION_TEXT("server")
- "built: " BUILD_DATE "\n"
- UNAME_RS ", " CC_VERSION "\n"
- );
+ char *msg;
+ size_t len;
+
+ if (cc->argc > 1 && strcmp(cc->argv[1], "-v") == 0)
+ len = xasprintf(&msg, "%s", version_text("server"));
+ else
+ len = xasprintf(&msg, "%s\n", version_single_line("server"));
+ return send_sb(&cc->scc, msg, len, SBD_OUTPUT, false);
}
+/** These status items are cleared if no audio file is currently open. */
#define EMPTY_STATUS_ITEMS \
ITEM(PATH) \
ITEM(DIRECTORY) \
ITEM(YEAR) \
ITEM(ALBUM) \
ITEM(COMMENT) \
- ITEM(AMPLIFICATION)
+ 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.
*/
-static char *empty_status_items(int parser_friendly)
+static unsigned empty_status_items(int parser_friendly, char **result)
{
+ char *esi;
+ unsigned len;
+
if (parser_friendly)
- return make_message(
+ len = xasprintf(&esi,
#define ITEM(x) "0004 %02x:\n"
EMPTY_STATUS_ITEMS
#undef ITEM
EMPTY_STATUS_ITEMS
#undef ITEM
);
- return make_message(
- #define ITEM(x) "%s:\n"
- EMPTY_STATUS_ITEMS
- #undef ITEM
- #define ITEM(x) ,status_item_list[SI_ ## x]
- EMPTY_STATUS_ITEMS
- #undef ITEM
- );
+ else
+ len = xasprintf(&esi,
+ #define ITEM(x) "%s:\n"
+ EMPTY_STATUS_ITEMS
+ #undef ITEM
+ #define ITEM(x) ,status_item_list[SI_ ## x]
+ EMPTY_STATUS_ITEMS
+ #undef ITEM
+ );
+ *result = esi;
+ return len;
}
#undef EMPTY_STATUS_ITEMS
/* stat */
-int com_stat(struct stream_cipher_context *scc, int argc, char * const * argv)
+static int com_stat(struct command_context *cc)
{
int i, ret;
struct misc_meta_data tmp, *nmmd = &tmp;
para_sigaction(SIGUSR1, dummy);
- for (i = 1; i < argc; i++) {
- const char *arg = argv[i];
+ for (i = 1; i < cc->argc; i++) {
+ const char *arg = cc->argv[i];
if (arg[0] != '-')
break;
if (!strcmp(arg, "--")) {
}
return -E_COMMAND_SYNTAX;
}
- if (i != argc)
+ if (i != cc->argc)
return -E_COMMAND_SYNTAX;
for (;;) {
mmd_dup(nmmd);
- s = get_status(nmmd, parser_friendly);
- ret = sc_send_buffer(scc, s);
- free(s);
+ ret = get_status(nmmd, parser_friendly, &s);
+ ret = send_sb(&cc->scc, s, ret, SBD_OUTPUT, false);
if (ret < 0)
goto out;
if (nmmd->vss_status_flags & VSS_NEXT) {
- static char *esi;
- if (!esi)
- esi = empty_status_items(parser_friendly);
- ret = sc_send_buffer(scc, esi);
+ char *esi;
+ ret = empty_status_items(parser_friendly, &esi);
+ ret = send_sb(&cc->scc, esi, ret, SBD_OUTPUT, false);
if (ret < 0)
goto out;
} else
- send_afs_status(scc, parser_friendly);
+ send_afs_status(cc, parser_friendly);
ret = 1;
if (num > 0 && !--num)
goto out;
sleep(50);
+ ret = -E_SERVER_CRASH;
if (getppid() == 1)
- return -E_SERVER_CRASH;
+ goto out;
}
out:
return ret;
}
-static int send_list_of_commands(struct stream_cipher_context *scc, struct server_command *cmd,
+static int send_list_of_commands(struct command_context *cc, struct server_command *cmd,
const char *handler)
{
- int ret, i;
+ char *msg = NULL;
- for (i = 1; cmd->name; cmd++, i++) {
- char *perms = cmd_perms_itohuman(cmd->perms);
- ret = sc_send_va_buffer(scc, "%s\t%s\t%s\t%s\n", cmd->name,
- handler,
- perms,
- cmd->description);
+ for (; cmd->name; cmd++) {
+ char *tmp, *perms = cmd_perms_itohuman(cmd->perms);
+ tmp = make_message("%s\t%s\t%s\t%s\n", cmd->name, handler,
+ perms, cmd->description);
free(perms);
- if (ret < 0)
- return ret;
+ msg = para_strcat(msg, tmp);
+ free(tmp);
}
- return 1;
+ assert(msg);
+ return send_sb(&cc->scc, msg, strlen(msg), SBD_OUTPUT, false);
}
/* returns string that must be freed by the caller */
}
/* help */
-int com_help(struct stream_cipher_context *scc, int argc, char * const * argv)
+static int com_help(struct command_context *cc)
{
struct server_command *cmd;
- char *perms, *handler;
+ char *perms, *handler, *buf;
int ret;
- if (argc < 2) {
+ if (cc->argc < 2) {
/* no argument given, print list of commands */
- if ((ret = send_list_of_commands(scc, server_cmds, "server")) < 0)
+ if ((ret = send_list_of_commands(cc, server_cmds, "server")) < 0)
return ret;
- return send_list_of_commands(scc, afs_cmds, "afs");
+ return send_list_of_commands(cc, afs_cmds, "afs");
}
/* argument given for help */
- cmd = get_cmd_ptr(argv[1], &handler);
+ cmd = get_cmd_ptr(cc->argv[1], &handler);
if (!cmd)
return -E_BAD_CMD;
perms = cmd_perms_itohuman(cmd->perms);
- ret = sc_send_va_buffer(scc,
- "%s - %s\n\n"
+ ret = xasprintf(&buf, "%s - %s\n\n"
"handler: %s\n"
"permissions: %s\n"
"usage: %s\n\n"
"%s\n",
- argv[1],
+ cc->argv[1],
cmd->description,
handler,
perms,
);
free(perms);
free(handler);
- return ret;
+ return send_sb(&cc->scc, buf, ret, SBD_OUTPUT, false);
}
/* hup */
-int com_hup(__a_unused struct stream_cipher_context *scc, int argc, __a_unused char * const * argv)
+static int com_hup(struct command_context *cc)
{
- if (argc != 1)
+ if (cc->argc != 1)
return -E_COMMAND_SYNTAX;
kill(getppid(), SIGHUP);
return 1;
}
/* term */
-int com_term(__a_unused struct stream_cipher_context *scc, int argc, __a_unused char * const * argv)
+static int com_term(struct command_context *cc)
{
- if (argc != 1)
+ if (cc->argc != 1)
return -E_COMMAND_SYNTAX;
kill(getppid(), SIGTERM);
return 1;
}
-int com_play(__a_unused struct stream_cipher_context *scc, int argc, __a_unused char * const * argv)
+static int com_play(struct command_context *cc)
{
- if (argc != 1)
+ if (cc->argc != 1)
return -E_COMMAND_SYNTAX;
mutex_lock(mmd_mutex);
mmd->new_vss_status_flags |= VSS_PLAYING;
mmd->new_vss_status_flags &= ~VSS_NOMORE;
mutex_unlock(mmd_mutex);
return 1;
-
}
/* stop */
-int com_stop(__a_unused struct stream_cipher_context *scc, int argc, __a_unused char * const * argv)
+static int com_stop(struct command_context *cc)
{
- if (argc != 1)
+ if (cc->argc != 1)
return -E_COMMAND_SYNTAX;
mutex_lock(mmd_mutex);
mmd->new_vss_status_flags &= ~VSS_PLAYING;
}
/* pause */
-int com_pause(__a_unused struct stream_cipher_context *scc, int argc, __a_unused char * const * argv)
+static int com_pause(struct command_context *cc)
{
- if (argc != 1)
+ if (cc->argc != 1)
return -E_COMMAND_SYNTAX;
mutex_lock(mmd_mutex);
if (!vss_paused() && !vss_stopped()) {
}
/* next */
-int com_next(__a_unused struct stream_cipher_context *scc, int argc, __a_unused char * const * argv)
+static int com_next(struct command_context *cc)
{
- if (argc != 1)
+ if (cc->argc != 1)
return -E_COMMAND_SYNTAX;
mutex_lock(mmd_mutex);
mmd->events++;
}
/* nomore */
-int com_nomore(__a_unused struct stream_cipher_context *scc, int argc, __a_unused char * const * argv)
+static int com_nomore(struct command_context *cc)
{
- if (argc != 1)
+ if (cc->argc != 1)
return -E_COMMAND_SYNTAX;
mutex_lock(mmd_mutex);
if (vss_playing() || vss_paused())
}
/* ff */
-int com_ff(__a_unused struct stream_cipher_context *scc, int argc, char * const * argv)
+static int com_ff(struct command_context *cc)
{
long promille;
int ret, backwards = 0;
unsigned i;
char c;
- if (argc != 2)
+ if (cc->argc != 2)
return -E_COMMAND_SYNTAX;
- if (!(ret = sscanf(argv[1], "%u%c", &i, &c)))
+ if (!(ret = sscanf(cc->argv[1], "%u%c", &i, &c)))
return -E_COMMAND_SYNTAX;
if (ret > 1 && c == '-')
backwards = 1; /* jmp backwards */
promille += 1000 * i / mmd->afd.afhi.seconds_total;
if (promille < 0)
promille = 0;
- if (promille > 1000) {
+ if (promille > 1000) {
mmd->new_vss_status_flags |= VSS_NEXT;
goto out;
}
}
/* jmp */
-int com_jmp(__a_unused struct stream_cipher_context *scc, int argc, char * const * argv)
+static int com_jmp(struct command_context *cc)
{
long unsigned int i;
int ret;
- if (argc != 2)
+ if (cc->argc != 2)
return -E_COMMAND_SYNTAX;
- if (sscanf(argv[1], "%lu", &i) <= 0)
+ if (sscanf(cc->argv[1], "%lu", &i) <= 0)
return -E_COMMAND_SYNTAX;
mutex_lock(mmd_mutex);
ret = -E_NO_AUDIO_FILE;
if (i > 100)
i = 100;
PARA_INFO_LOG("jumping to %lu%%\n", i);
- mmd->repos_request = (mmd->afd.afhi.chunks_total * i + 50)/ 100;
- PARA_INFO_LOG("sent: %lu, offset before jmp: %lu\n",
+ mmd->repos_request = (mmd->afd.afhi.chunks_total * i + 50) / 100;
+ PARA_INFO_LOG("sent: %lu, offset before jmp: %lu\n",
mmd->chunks_sent, mmd->offset);
mmd->new_vss_status_flags |= VSS_REPOS;
mmd->new_vss_status_flags &= ~VSS_NEXT;
return ret;
}
+static int com_tasks(struct command_context *cc)
+{
+ char *tl = server_get_tasks();
+ int ret = 1;
+
+ if (tl)
+ ret = send_sb(&cc->scc, tl, strlen(tl), SBD_OUTPUT, false);
+ return ret;
+}
+
/*
* 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, struct server_command *cmd_ptr)
+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;
}
-/*
- * Parse first string from *cmd and lookup in table of valid commands.
- * On error, NULL is returned.
- */
-static struct server_command *parse_cmd(const char *cmdstr)
+static void reset_signals(void)
{
- char buf[255];
- int n = 0;
-
- sscanf(cmdstr, "%200s%n", buf, &n);
- if (!n)
- return NULL;
- buf[n] = '\0';
- return get_cmd_ptr(buf, NULL);
+ para_sigaction(SIGCHLD, SIG_IGN);
+ para_sigaction(SIGINT, SIG_DFL);
+ para_sigaction(SIGTERM, SIG_DFL);
+ para_sigaction(SIGHUP, SIG_DFL);
}
-static int read_command(struct stream_cipher_context *scc, char **result)
+struct connection_features {
+ bool sideband_requested;
+ bool aes_ctr128_requested;
+};
+
+static int parse_auth_request(char *buf, int len, struct user **u,
+ struct connection_features *cf)
{
int ret;
- char buf[4096];
- char *command = NULL;
+ char *p, *username, **features = NULL;
+ size_t auth_rq_len = strlen(AUTH_REQUEST_MSG);
- for (;;) {
- size_t numbytes;
- char *p;
-
- ret = sc_recv_buffer(scc, buf, sizeof(buf));
- if (ret < 0)
- goto out;
- if (!ret)
- break;
- numbytes = ret;
- ret = -E_COMMAND_SYNTAX;
- if (command && numbytes + strlen(command) > MAX_COMMAND_LEN) /* DOS */
- goto out;
- command = para_strcat(command, buf);
- p = strstr(command, EOC_MSG);
- if (p) {
- *p = '\0';
- break;
+ *u = NULL;
+ memset(cf, 0, sizeof(*cf));
+ if (len < auth_rq_len + 2)
+ return -E_AUTH_REQUEST;
+ if (strncmp(buf, AUTH_REQUEST_MSG, auth_rq_len) != 0)
+ return -E_AUTH_REQUEST;
+ username = buf + auth_rq_len;
+ p = strchr(username, ' ');
+ if (p) {
+ int i;
+ if (p == username)
+ return -E_AUTH_REQUEST;
+ *p = '\0';
+ p++;
+ create_argv(p, ",", &features);
+ for (i = 0; features[i]; i++) {
+ if (strcmp(features[i], "sideband") == 0)
+ cf->sideband_requested = true;
+ else if (strcmp(features[i], "aes_ctr128") == 0)
+ cf->aes_ctr128_requested = true;
+ else {
+ ret = -E_BAD_FEATURE;
+ goto out;
+ }
}
}
- ret = command? 1 : -E_COMMAND_SYNTAX;
+ PARA_DEBUG_LOG("received auth request for user %s\n", username);
+ *u = lookup_user(username);
+ ret = 1;
out:
- if (ret < 0)
- free(command);
- else
- *result = command;
+ free_argv(features);
return ret;
-
}
-static void reset_signals(void)
+#define HANDSHAKE_BUFSIZE 4096
+
+static int run_command(struct command_context *cc, struct iovec *iov,
+ const char *peername)
{
- para_sigaction(SIGCHLD, SIG_IGN);
- para_sigaction(SIGINT, SIG_DFL);
- para_sigaction(SIGTERM, SIG_DFL);
- para_sigaction(SIGHUP, SIG_DFL);
+ int ret, i;
+ char *p, *end;
+ struct server_command *cmd;
+
+ if (iov->iov_base == NULL || iov->iov_len == 0)
+ return -E_BAD_CMD;
+ p = iov->iov_base;
+ p[iov->iov_len - 1] = '\0'; /* just to be sure */
+ cmd = get_cmd_ptr(p, NULL);
+ if (!cmd)
+ return -E_BAD_CMD;
+ ret = check_perms(cc->u->perms, cmd);
+ if (ret < 0)
+ return ret;
+ 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 *));
+ for (i = 0, p = iov->iov_base; p < end; i++) {
+ cc->argv[i] = para_strdup(p);
+ p += strlen(p) + 1;
+ }
+ cc->argv[cc->argc] = NULL;
+ PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cmd->name,
+ cc->u->name, peername);
+ ret = cmd->handler(cc);
+ free_argv(cc->argv);
+ mutex_lock(mmd_mutex);
+ mmd->num_commands++;
+ if (ret >= 0 && (cmd->perms & AFS_WRITE))
+ mmd->events++;
+ mutex_unlock(mmd_mutex);
+ return ret;
}
/**
* \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.
+ * Whenever para_server accepts an incoming tcp connection on the port it
+ * listens on, it forks and the resulting child calls this function.
*
- * An RSA-based challenge/response is used to authenticate
- * the peer. It that authentication succeeds, a random
- * session key is generated and sent back to the peer,
- * encrypted with its RSA public key. From this point on,
- * all transfers are crypted with this session key.
+ * An RSA-based challenge/response is used to authenticate the peer. It that
+ * authentication succeeds, a random session key is generated and sent back to
+ * the peer, encrypted with its RSA public key. From this point on, all
+ * transfers are crypted with this session key.
*
- * Next it is checked if the peer supplied a valid server command or a command
- * for the audio file selector. If yes, and if the user has sufficient
+ * Next it is checked if the peer supplied a valid server command or a command
+ * for the audio file selector. If yes, and if the user has sufficient
* 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 the function if the connection was not
- * authenticated when the timeout expires.
+ * In order to cope with a 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
*/
__noreturn void handle_connect(int fd, const char *peername)
{
- int ret, argc;
- char buf[4096];
+ int ret;
unsigned char rand_buf[CHALLENGE_SIZE + 2 * SESSION_KEY_LEN];
unsigned char challenge_hash[HASH_SIZE];
- struct user *u;
- struct server_command *cmd = NULL;
- char **argv = NULL;
- char *p, *command = NULL;
+ char *command = NULL, *buf = para_malloc(HANDSHAKE_BUFSIZE) /* must be on the heap */;
size_t numbytes;
- struct stream_cipher_context scc = {.fd = fd};
+ struct command_context cc_struct = {.peer = peername}, *cc = &cc_struct;
+ struct iovec iov;
+ struct connection_features cf;
+ cc->scc.fd = fd;
reset_signals();
/* we need a blocking fd here as recv() might return EAGAIN otherwise. */
ret = mark_fd_blocking(fd);
if (ret < 0)
goto net_err;
/* send Welcome message */
- ret = send_va_buffer(fd, "This is para_server, version "
- PACKAGE_VERSION ".\n" );
+ ret = write_va_buffer(fd, "This is para_server, version "
+ PACKAGE_VERSION ".\n"
+ "Features: sideband,aes_ctr128\n"
+ );
if (ret < 0)
goto net_err;
/* recv auth request line */
- ret = recv_buffer(fd, buf, sizeof(buf));
+ ret = recv_buffer(fd, buf, HANDSHAKE_BUFSIZE);
if (ret < 0)
goto net_err;
- if (ret < 10) {
- ret = -E_AUTH_REQUEST;
+ ret = parse_auth_request(buf, ret, &cc->u, &cf);
+ if (ret < 0)
goto net_err;
- }
- ret = -E_AUTH_REQUEST;
- if (strncmp(buf, AUTH_REQUEST_MSG, strlen(AUTH_REQUEST_MSG)))
+ if (!cf.sideband_requested) { /* sideband is mandatory */
+ PARA_ERROR_LOG("client did not request sideband\n");
+ ret = -E_BAD_FEATURE;
goto net_err;
- p = buf + strlen(AUTH_REQUEST_MSG);
- PARA_DEBUG_LOG("received auth request for user %s\n", p);
- u = lookup_user(p);
- if (u) {
+ }
+ if (cc->u) {
get_random_bytes_or_die(rand_buf, sizeof(rand_buf));
- ret = pub_encrypt(u->pubkey, rand_buf, sizeof(rand_buf),
+ ret = pub_encrypt(cc->u->pubkey, rand_buf, sizeof(rand_buf),
(unsigned char *)buf);
if (ret < 0)
goto net_err;
numbytes = 256;
get_random_bytes_or_die((unsigned char *)buf, numbytes);
}
- PARA_DEBUG_LOG("sending %u byte challenge + rc4 keys (%zu bytes)\n",
+ PARA_DEBUG_LOG("sending %u byte challenge + session key (%zu bytes)\n",
CHALLENGE_SIZE, numbytes);
- ret = send_bin_buffer(fd, buf, numbytes);
+ ret = send_sb(&cc->scc, buf, numbytes, SBD_CHALLENGE, false);
+ buf = NULL;
if (ret < 0)
goto net_err;
- /* recv challenge response */
- ret = recv_bin_buffer(fd, buf, HASH_SIZE);
+ ret = recv_sb(&cc->scc, SBD_CHALLENGE_RESPONSE,
+ HANDSHAKE_BUFSIZE, &iov);
if (ret < 0)
goto net_err;
- numbytes = ret;
- PARA_DEBUG_LOG("received %d bytes challenge response\n", ret);
+ buf = iov.iov_base;
+ numbytes = iov.iov_len;
+ PARA_DEBUG_LOG("received %zu bytes challenge response\n", numbytes);
ret = -E_BAD_USER;
- if (!u)
+ if (!cc->u)
goto net_err;
/*
* The correct response is the hash of the first CHALLENGE_SIZE bytes
goto net_err;
/* auth successful */
alarm(0);
- PARA_INFO_LOG("good auth for %s\n", u->name);
+ PARA_INFO_LOG("good auth for %s\n", cc->u->name);
/* init stream cipher keys with the second part of the random buffer */
- scc.recv = sc_new(rand_buf + CHALLENGE_SIZE, SESSION_KEY_LEN);
- scc.send = sc_new(rand_buf + CHALLENGE_SIZE + SESSION_KEY_LEN, SESSION_KEY_LEN);
- ret = sc_send_buffer(&scc, PROCEED_MSG);
+ cc->scc.recv = sc_new(rand_buf + CHALLENGE_SIZE, SESSION_KEY_LEN,
+ cf.aes_ctr128_requested);
+ cc->scc.send = sc_new(rand_buf + CHALLENGE_SIZE + SESSION_KEY_LEN,
+ SESSION_KEY_LEN, cf.aes_ctr128_requested);
+ ret = send_sb(&cc->scc, NULL, 0, SBD_PROCEED, false);
if (ret < 0)
goto net_err;
- ret = read_command(&scc, &command);
- if (ret == -E_COMMAND_SYNTAX)
- goto err_out;
+ ret = recv_sb(&cc->scc, SBD_COMMAND, MAX_COMMAND_LEN, &iov);
if (ret < 0)
goto net_err;
- ret = -E_BAD_CMD;
- cmd = parse_cmd(command);
- if (!cmd)
- goto err_out;
- /* valid command, check permissions */
- ret = check_perms(u->perms, cmd);
- if (ret < 0)
- goto err_out;
- /* valid command and sufficient perms */
- ret = create_argv(command, "\n", &argv);
+ ret = run_command(cc, &iov, peername);
+ free(iov.iov_base);
if (ret < 0)
goto err_out;
- argc = ret;
- PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cmd->name, u->name,
- peername);
- ret = cmd->handler(&scc, argc, argv);
- free_argv(argv);
- mutex_lock(mmd_mutex);
- mmd->num_commands++;
- mutex_unlock(mmd_mutex);
if (ret >= 0)
goto out;
err_out:
- sc_send_va_buffer(&scc, "%s\n", para_strerror(-ret));
+ if (send_strerror(cc, -ret) >= 0)
+ send_sb(&cc->scc, NULL, 0, SBD_EXIT__FAILURE, true);
net_err:
PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
out:
+ free(buf);
free(command);
- sc_free(scc.recv);
- sc_free(scc.send);
mutex_lock(mmd_mutex);
- if (cmd && (cmd->perms & AFS_WRITE) && ret >= 0)
- mmd->events++;
mmd->active_connections--;
mutex_unlock(mmd_mutex);
+ if (ret >= 0) {
+ ret = send_sb(&cc->scc, NULL, 0, SBD_EXIT__SUCCESS, true);
+ if (ret < 0)
+ PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
+ }
+ sc_free(cc->scc.recv);
+ sc_free(cc->scc.send);
exit(ret < 0? EXIT_FAILURE : EXIT_SUCCESS);
}