Merge branch 'maint'
[paraslash.git] / command.c
index 2e733c5..2ef9c5a 100644 (file)
--- a/command.c
+++ b/command.c
@@ -1,15 +1,20 @@
 /*
- * Copyright (C) 1997-2013 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/types.h>
 #include <osl.h>
+#include <arpa/inet.h>
+#include <sys/un.h>
+#include <netdb.h>
 
 #include "para.h"
 #include "error.h"
 #include "fd.h"
 #include "ipc.h"
 #include "user_list.h"
-#include "server_command_list.h"
-#include "afs_command_list.h"
+#include "server.command_list.h"
+#include "afs.command_list.h"
 #include "signal.h"
 #include "version.h"
 
-struct server_command afs_cmds[] = {DEFINE_AFS_CMD_ARRAY};
-struct server_command server_cmds[] = {DEFINE_SERVER_CMD_ARRAY};
+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
@@ -110,7 +115,6 @@ static unsigned get_status(struct misc_meta_data *nmmd, int parser_friendly,
        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;
@@ -144,7 +148,6 @@ static unsigned get_status(struct misc_meta_data *nmmd, int parser_friendly,
                (long unsigned)current_time.tv_usec);
        free(flags);
        free(status);
-       free(ut);
        *result = b.buf;
        return b.offset;
 }
@@ -207,7 +210,7 @@ static int check_sender_args(int argc, char * const * argv, struct sender_comman
  *
  * The nonblock flag must be disabled for the file descriptor given by \a scc.
  *
- * Stream cipher encryption is automatically activated if neccessary via the
+ * Stream cipher encryption is automatically activated if necessary via the
  * sideband transformation, depending on the value of \a band.
  *
  * \return Standard.
@@ -220,8 +223,8 @@ int send_sb(struct stream_cipher_context *scc, void *buf, size_t numbytes,
        int ret;
        struct sb_context *sbc;
        struct iovec iov[2];
-       struct sb_buffer sbb = SBB_INIT(band, buf, numbytes);
        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 {
@@ -268,10 +271,7 @@ __printf_3_4 int send_sb_va(struct stream_cipher_context *scc, int band,
  */
 int send_strerror(struct command_context *cc, int err)
 {
-       return cc->use_sideband?
-               send_sb_va(&cc->scc, SBD_ERROR_LOG, "%s\n", para_strerror(err))
-       :
-               sc_send_va_buffer(&cc->scc, "%s\n", para_strerror(err));
+       return send_sb_va(&cc->scc, SBD_ERROR_LOG, "%s\n", para_strerror(err));
 }
 
 /**
@@ -338,23 +338,17 @@ static int com_sender(struct command_context *cc)
                        free(msg);
                        msg = tmp;
                }
-               if (cc->use_sideband)
-                       return send_sb(&cc->scc, msg, ret, SBD_OUTPUT, false);
-               ret = sc_send_buffer(&cc->scc, msg);
-               free(msg);
-               return ret;
+               return send_sb(&cc->scc, msg, ret, SBD_OUTPUT, false);
        }
        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();
-               if (cc->use_sideband)
-                       return send_sb(&cc->scc, msg, strlen(msg), SBD_OUTPUT,
-                               false);
-               ret = sc_send_buffer(&cc->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) {
@@ -369,11 +363,13 @@ static int com_sender(struct command_context *cc)
        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;
        }
@@ -383,28 +379,20 @@ static int com_sender(struct command_context *cc)
 /* server info */
 static int com_si(struct command_context *cc)
 {
-       int i, ret;
-       char *msg, *ut, *sender_info = NULL;
+       int ret;
+       char *msg, *ut;
 
        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);
+       ut = daemon_get_uptime_str(now);
        ret = xasprintf(&msg,
-               "version: %s\n"
                "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",
-               version_git(),
+               "supported audio formats: %s\n",
                ut, mmd->num_played,
                (int)getppid(),
                (int)mmd->afs_pid,
@@ -412,17 +400,11 @@ static int com_si(struct command_context *cc)
                mmd->num_commands,
                mmd->num_connects,
                conf.loglevel_arg,
-               AUDIO_FORMAT_HANDLERS,
-               sender_info
+               AUDIO_FORMAT_HANDLERS
        );
        mutex_unlock(mmd_mutex);
        free(ut);
-       free(sender_info);
-       if (cc->use_sideband)
-               return send_sb(&cc->scc, msg, ret, SBD_OUTPUT, false);
-       ret = sc_send_bin_buffer(&cc->scc, msg, ret);
-       free(msg);
-       return ret;
+       return send_sb(&cc->scc, msg, ret, SBD_OUTPUT, false);
 }
 
 /* version */
@@ -434,9 +416,7 @@ static int com_version(struct command_context *cc)
        if (cc->argc != 1)
                return -E_COMMAND_SYNTAX;
        len = xasprintf(&msg, "%s", version_text("server"));
-       if (cc->use_sideband)
-               return send_sb(&cc->scc, msg, len, SBD_OUTPUT, false);
-       return sc_send_bin_buffer(&cc->scc, msg, len);
+       return send_sb(&cc->scc, msg, len, SBD_OUTPUT, false);
 }
 
 /** These status items are cleared if no audio file is currently open. */
@@ -541,24 +521,13 @@ static int com_stat(struct command_context *cc)
        for (;;) {
                mmd_dup(nmmd);
                ret = get_status(nmmd, parser_friendly, &s);
-               if (cc->use_sideband)
-                       ret = send_sb(&cc->scc, s, ret, SBD_OUTPUT, false);
-               else {
-                       ret = sc_send_bin_buffer(&cc->scc, s, ret);
-                       free(s);
-               }
+               ret = send_sb(&cc->scc, s, ret, SBD_OUTPUT, false);
                if (ret < 0)
                        goto out;
                if (nmmd->vss_status_flags & VSS_NEXT) {
                        char *esi;
                        ret = empty_status_items(parser_friendly, &esi);
-                       if (cc->use_sideband)
-                               ret = send_sb(&cc->scc, esi, ret, SBD_OUTPUT,
-                                       false);
-                       else {
-                               ret = sc_send_bin_buffer(&cc->scc, esi, ret);
-                               free(esi);
-                       }
+                       ret = send_sb(&cc->scc, esi, ret, SBD_OUTPUT, false);
                        if (ret < 0)
                                goto out;
                } else
@@ -578,7 +547,6 @@ out:
 static int send_list_of_commands(struct command_context *cc, struct server_command *cmd,
                const char *handler)
 {
-       int ret;
        char *msg = NULL;
 
        for (; cmd->name; cmd++) {
@@ -589,11 +557,8 @@ static int send_list_of_commands(struct command_context *cc, struct server_comma
                msg = para_strcat(msg, tmp);
                free(tmp);
        }
-       if (cc->use_sideband)
-               return send_sb(&cc->scc, msg, strlen(msg), SBD_OUTPUT, false);
-       ret = sc_send_buffer(&cc->scc, msg);
-       free(msg);
-       return ret;
+       assert(msg);
+       return send_sb(&cc->scc, msg, strlen(msg), SBD_OUTPUT, false);
 }
 
 /* returns string that must be freed by the caller */
@@ -649,11 +614,7 @@ static int com_help(struct command_context *cc)
        );
        free(perms);
        free(handler);
-       if (cc->use_sideband)
-               return send_sb(&cc->scc, buf, ret, SBD_OUTPUT, false);
-       ret = sc_send_buffer(&cc->scc, buf);
-       free(buf);
-       return ret;
+       return send_sb(&cc->scc, buf, ret, SBD_OUTPUT, false);
 }
 
 /* hup */
@@ -762,7 +723,7 @@ static int com_ff(struct command_context *cc)
                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;
        }
@@ -793,8 +754,8 @@ static int com_jmp(struct command_context *cc)
        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;
@@ -805,6 +766,16 @@ out:
        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.
@@ -815,58 +786,6 @@ static int check_perms(unsigned int perms, struct server_command *cmd_ptr)
        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)
-{
-       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);
-}
-
-static int read_command(struct stream_cipher_context *scc, char **result)
-{
-       int ret;
-       char buf[4096];
-       char *command = NULL;
-
-       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;
-               }
-       }
-       ret = command? 1 : -E_COMMAND_SYNTAX;
-out:
-       if (ret < 0)
-               free(command);
-       else
-               *result = command;
-       return ret;
-
-}
-
 static void reset_signals(void)
 {
        para_sigaction(SIGCHLD, SIG_IGN);
@@ -875,15 +794,20 @@ static void reset_signals(void)
        para_sigaction(SIGHUP, SIG_DFL);
 }
 
+struct connection_features {
+       bool sideband_requested;
+       bool aes_ctr128_requested;
+};
+
 static int parse_auth_request(char *buf, int len, struct user **u,
-               bool *use_sideband)
+               struct connection_features *cf)
 {
        int ret;
        char *p, *username, **features = NULL;
        size_t auth_rq_len = strlen(AUTH_REQUEST_MSG);
 
        *u = NULL;
-       *use_sideband = false;
+       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)
@@ -899,15 +823,16 @@ static int parse_auth_request(char *buf, int len, struct user **u,
                create_argv(p, ",", &features);
                for (i = 0; features[i]; i++) {
                        if (strcmp(features[i], "sideband") == 0)
-                               *use_sideband = true;
+                               cf->sideband_requested = true;
+                       else if (strcmp(features[i], "aes_ctr128") == 0)
+                               cf->aes_ctr128_requested = true;
                        else {
                                ret = -E_BAD_FEATURE;
                                goto out;
                        }
                }
        }
-       PARA_DEBUG_LOG("received auth request for user %s (sideband = %s)\n",
-               username, *use_sideband? "true" : "false");
+       PARA_DEBUG_LOG("received auth request for user %s\n", username);
        *u = lookup_user(username);
        ret = 1;
 out:
@@ -934,7 +859,7 @@ static int parse_sb_command(struct command_context *cc, struct iovec *iov)
        if (ret < 0)
                goto out;
        end = iov->iov_base + iov->iov_len;
-       for (i = 0, p = iov->iov_base; p < end; i++)
+       for (i = 0; p < end; i++)
                p += strlen(p) + 1;
        cc->argc = i;
        cc->argv = para_malloc((cc->argc + 1) * sizeof(char *));
@@ -955,24 +880,22 @@ out:
  * \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
  */
@@ -981,9 +904,11 @@ __noreturn void handle_connect(int fd, const char *peername)
        int ret;
        unsigned char rand_buf[CHALLENGE_SIZE + 2 * SESSION_KEY_LEN];
        unsigned char challenge_hash[HASH_SIZE];
-       char *p, *command = NULL, *buf = para_malloc(HANDSHAKE_BUFSIZE) /* must be on the heap */;
+       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 iovec iov;
+       struct connection_features cf;
 
        cc->scc.fd = fd;
        reset_signals();
@@ -993,8 +918,8 @@ __noreturn void handle_connect(int fd, const char *peername)
                goto net_err;
        /* send Welcome message */
        ret = write_va_buffer(fd, "This is para_server, version "
-               PACKAGE_VERSION  ".\n"
-               "Features: sideband\n"
+               PACKAGE_VERSION ".\n"
+               "Features: sideband,aes_ctr128\n"
        );
        if (ret < 0)
                goto net_err;
@@ -1002,12 +927,14 @@ __noreturn void handle_connect(int fd, const char *peername)
        ret = recv_buffer(fd, buf, HANDSHAKE_BUFSIZE);
        if (ret < 0)
                goto net_err;
-       ret = parse_auth_request(buf, ret, &cc->u, &cc->use_sideband);
+       ret = parse_auth_request(buf, ret, &cc->u, &cf);
        if (ret < 0)
                goto net_err;
-       p = buf + strlen(AUTH_REQUEST_MSG);
-       PARA_DEBUG_LOG("received auth request for user %s\n", p);
-       cc->u = lookup_user(p);
+       if (!cf.sideband_requested) { /* sideband is mandatory */
+               PARA_ERROR_LOG("client did not request sideband\n");
+               ret = -E_BAD_FEATURE;
+               goto net_err;
+       }
        if (cc->u) {
                get_random_bytes_or_die(rand_buf, sizeof(rand_buf));
                ret = pub_encrypt(cc->u->pubkey, rand_buf, sizeof(rand_buf),
@@ -1024,30 +951,18 @@ __noreturn void handle_connect(int fd, const char *peername)
                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);
-       if (cc->use_sideband) {
-               struct iovec iov;
-               ret = send_sb(&cc->scc, buf, numbytes, SBD_CHALLENGE, false);
-               buf = NULL;
-               if (ret < 0)
-                       goto net_err;
-               ret = recv_sb(&cc->scc, SBD_CHALLENGE_RESPONSE,
-                       HANDSHAKE_BUFSIZE, &iov);
-               if (ret < 0)
-                       goto net_err;
-               buf = iov.iov_base;
-               numbytes = iov.iov_len;
-       } else {
-               ret = write_all(fd, buf, numbytes);
-               if (ret < 0)
-                       goto net_err;
-               /* recv challenge response */
-               ret = recv_bin_buffer(fd, buf, HASH_SIZE);
-               if (ret < 0)
-                       goto net_err;
-               numbytes = ret;
-       }
+       ret = send_sb(&cc->scc, buf, numbytes, SBD_CHALLENGE, false);
+       buf = NULL;
+       if (ret < 0)
+               goto net_err;
+       ret = recv_sb(&cc->scc, SBD_CHALLENGE_RESPONSE,
+               HANDSHAKE_BUFSIZE, &iov);
+       if (ret < 0)
+               goto net_err;
+       buf = iov.iov_base;
+       numbytes = iov.iov_len;
        PARA_DEBUG_LOG("received %zu bytes challenge response\n", numbytes);
        ret = -E_BAD_USER;
        if (!cc->u)
@@ -1066,43 +981,20 @@ __noreturn void handle_connect(int fd, const char *peername)
        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);
-       cc->scc.send = sc_new(rand_buf + CHALLENGE_SIZE + SESSION_KEY_LEN, SESSION_KEY_LEN);
-       if (cc->use_sideband)
-               ret = send_sb(&cc->scc, NULL, 0, SBD_PROCEED, false);
-       else
-               ret = sc_send_buffer(&cc->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;
-       if (cc->use_sideband) {
-               struct iovec iov;
-               ret = recv_sb(&cc->scc, SBD_COMMAND, MAX_COMMAND_LEN, &iov);
-               if (ret < 0)
-                       goto net_err;
-               ret = parse_sb_command(cc, &iov);
-               if (ret < 0)
-                       goto err_out;
-               cc->argc = ret;
-       } else {
-               ret = read_command(&cc->scc, &command);
-               if (ret == -E_COMMAND_SYNTAX)
-                       goto err_out;
-               if (ret < 0)
-                       goto net_err;
-               ret = -E_BAD_CMD;
-               cc->cmd = parse_cmd(command);
-               if (!cc->cmd)
-                       goto err_out;
-               /* valid command, check permissions */
-               ret = check_perms(cc->u->perms, cc->cmd);
-               if (ret < 0)
-                       goto err_out;
-               /* valid command and sufficient perms */
-               ret = create_argv(command, "\n", &cc->argv);
-               if (ret < 0)
-                       goto err_out;
-               cc->argc = ret;
-       }
+       ret = recv_sb(&cc->scc, SBD_COMMAND, MAX_COMMAND_LEN, &iov);
+       if (ret < 0)
+               goto net_err;
+       ret = parse_sb_command(cc, &iov);
+       if (ret < 0)
+               goto err_out;
+       cc->argc = ret;
        PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cc->cmd->name,
                cc->u->name, peername);
        ret = cc->cmd->handler(cc);
@@ -1113,7 +1005,7 @@ __noreturn void handle_connect(int fd, const char *peername)
        if (ret >= 0)
                goto out;
 err_out:
-       if (send_strerror(cc, -ret) >= 0 && cc->use_sideband)
+       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));
@@ -1125,7 +1017,7 @@ out:
                mmd->events++;
        mmd->active_connections--;
        mutex_unlock(mmd_mutex);
-       if (ret >= 0 && cc->use_sideband) {
+       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));