diff options
Diffstat (limited to 'scd/command.c')
| -rw-r--r-- | scd/command.c | 361 |
1 files changed, 282 insertions, 79 deletions
diff --git a/scd/command.c b/scd/command.c index ea296b6fb..9881b1be0 100644 --- a/scd/command.c +++ b/scd/command.c @@ -26,6 +26,9 @@ #include <ctype.h> #include <unistd.h> #include <signal.h> +#ifdef USE_GNU_PTH +# include <pth.h> +#endif #include <assuan.h> @@ -38,11 +41,6 @@ #define MAXLEN_PIN 100 -/* We keep track of the primary client using scdaemon. This one will - for example receive signal on card change. */ -static ctrl_t primary_connection; - - #define set_error(e,t) assuan_set_error (ctx, ASSUAN_ ## e, (t)) @@ -52,20 +50,65 @@ static ctrl_t primary_connection; int _r = (r); \ if (gpg_err_code (_r) == GPG_ERR_CARD_NOT_PRESENT \ || gpg_err_code (_r) == GPG_ERR_CARD_REMOVED) \ - (c)->server_local->card_removed = 1; \ + update_card_removed ((c)->reader_slot, 1); \ } while (0) +#define IS_LOCKED(c) \ + (locked_session && locked_session != (c)->server_local \ + && (c)->reader_slot != -1 && locked_session->ctrl_backlink \ + && (c)->reader_slot == locked_session->ctrl_backlink->reader_slot) + -/* Data used to associate an Assuan context with local server data */ +/* Data used to associate an Assuan context with local server data. + This object describes the local properties of one session. */ struct server_local_s { + /* We keep a list of all active sessions with the anchor at + SESSION_LIST (see below). This field is used for linking. */ + struct server_local_s *next_session; + + /* This object is usually assigned to a CTRL object (which is + globally visible). While enumeratin all sessions we sometimes + need to access data of the CTRL object; thus we keep a + backpointer here. */ + ctrl_t ctrl_backlink; + + /* The Assuan context used by this session/server. */ assuan_context_t assuan_ctx; + int event_signal; /* Or 0 if not used. */ - int card_removed; /* True if the card has been removed and a - reset is required to continue - operation. */ + + /* True if the card has been removed and a reset is required to + continue operation. */ + int card_removed; }; +/* To keep track of all running sessions, we link all active server + contexts and the anchor in this variable. */ +static struct server_local_s *session_list; + +/* If a session has been locked we store a link to its server object + in this variable. */ +static struct server_local_s *locked_session; + + + + +/* Update the CARD_REMOVED element of all sessions using the reader + given by SLOT to VALUE */ +static void +update_card_removed (int slot, int value) +{ + struct server_local_s *sl; + + for (sl=session_list; sl; sl = sl->next_session) + if (sl->ctrl_backlink + && sl->ctrl_backlink->reader_slot == slot) + sl->card_removed = value; +} + + + /* Check whether the option NAME appears in LINE */ static int has_option (const char *line, const char *name) @@ -79,10 +122,13 @@ has_option (const char *line, const char *name) /* Reset the card and free the application context. With DO_CLOSE set - to true, close the reader and don't do just a reset. */ + to true and this is the last session with a reference to teh + reader, close the reader and don't do just a reset. */ static void do_reset (ctrl_t ctrl, int do_close) { + int slot = ctrl->reader_slot; + if (ctrl->card_ctx) { card_close (ctrl->card_ctx); @@ -97,20 +143,61 @@ do_reset (ctrl_t ctrl, int do_close) } if (ctrl->reader_slot != -1) { - if (do_close || apdu_reset (ctrl->reader_slot)) + struct server_local_s *sl; + + /* If we are the only session with the reader open we may close + it. If not, do a reset unless the a lock is held on the + reader. */ + for (sl=session_list; sl; sl = sl->next_session) + if (sl != ctrl->server_local + && sl->ctrl_backlink->reader_slot == ctrl->reader_slot) + break; + if (sl) /* There is another session with the reader open. */ + { + if ( IS_LOCKED (ctrl) ) /* If it is locked, release it. */ + ctrl->reader_slot = -1; + else + { + if (do_close) /* Always mark reader unused. */ + ctrl->reader_slot = -1; + else if (apdu_reset (ctrl->reader_slot)) /* Reset only if + not locked */ + { + /* The reset failed. Mark the reader as closed. */ + ctrl->reader_slot = -1; + } + + if (locked_session && ctrl->server_local == locked_session) + { + locked_session = NULL; + log_debug ("implicitly unlocking due to RESET\n"); + } + } + } + else /* No other session has the reader open. */ { - apdu_close_reader (ctrl->reader_slot); - ctrl->reader_slot = -1; + if (do_close || apdu_reset (ctrl->reader_slot)) + { + apdu_close_reader (ctrl->reader_slot); + ctrl->reader_slot = -1; + } + if ( IS_LOCKED (ctrl) ) + { + log_debug ("WARNING: cleaning up stale session lock\n"); + locked_session = NULL; + } } } - ctrl->server_local->card_removed = 0; + + /* Reset card removed flag for the current reader. */ + update_card_removed (slot, 0); } static void reset_notify (assuan_context_t ctx) { - CTRL ctrl = assuan_get_pointer (ctx); + ctrl_t ctrl = assuan_get_pointer (ctx); do_reset (ctrl, 0); } @@ -134,6 +221,27 @@ option_handler (assuan_context_t ctx, const char *key, const char *value) } +/* Return the slot of the current reader or open the reader if no + other sessions are using a reader. Note, that we currently support + only one reader but most of the code (except for this function) + should be able to cope with several readers. */ +static int +get_reader_slot (void) +{ + struct server_local_s *sl; + int slot= -1; + + for (sl=session_list; sl; sl = sl->next_session) + if (sl->ctrl_backlink + && (slot = sl->ctrl_backlink->reader_slot) != -1) + break; + + if (slot == -1) + slot = apdu_open_reader (opt.reader_port); + + return slot; +} + /* If the card has not yet been opened, do it. Note that this function returns an Assuan error, so don't map the error a second time */ @@ -154,10 +262,13 @@ open_card (ctrl_t ctrl, const char *apptype) if (ctrl->card_ctx) return 0; /* Already initialized using a card context. */ + if ( IS_LOCKED (ctrl) ) + return gpg_error (GPG_ERR_EBUSY); + if (ctrl->reader_slot != -1) slot = ctrl->reader_slot; else - slot = apdu_open_reader (opt.reader_port); + slot = get_reader_slot (); ctrl->reader_slot = slot; if (slot == -1) err = gpg_error (GPG_ERR_CARD); @@ -177,9 +288,7 @@ open_card (ctrl_t ctrl, const char *apptype) err = card_open (&ctrl->card_ctx); } - if (gpg_err_code (err) == GPG_ERR_CARD_NOT_PRESENT) - ctrl->server_local->card_removed = 1; - + TEST_CARD_REMOVAL (ctrl, err); return map_to_assuan_status (err); } @@ -248,12 +357,12 @@ cmd_serialno (assuan_context_t ctx, char *line) time_t stamp; /* Clear the remove flag so that the open_card is able to reread it. */ - - /* FIXME: We can't do that if we are in a locked state. Retrun an - appropriate erro r in that case. IF the card has not been - removed we may very well continue. */ if (ctrl->server_local->card_removed) - do_reset (ctrl, 0); + { + if ( IS_LOCKED (ctrl) ) + return gpg_error (GPG_ERR_EBUSY); + do_reset (ctrl, 0); + } if ((rc = open_card (ctrl, *line? line:NULL))) return rc; @@ -342,7 +451,7 @@ cmd_serialno (assuan_context_t ctx, char *line) static int cmd_learn (assuan_context_t ctx, char *line) { - CTRL ctrl = assuan_get_pointer (ctx); + ctrl_t ctrl = assuan_get_pointer (ctx); int rc = 0; int idx; @@ -491,7 +600,7 @@ cmd_learn (assuan_context_t ctx, char *line) static int cmd_readcert (assuan_context_t ctx, char *line) { - CTRL ctrl = assuan_get_pointer (ctx); + ctrl_t ctrl = assuan_get_pointer (ctx); int rc; unsigned char *cert; size_t ncert; @@ -630,12 +739,13 @@ cmd_readkey (assuan_context_t ctx, char *line) static int cmd_setdata (assuan_context_t ctx, char *line) { - CTRL ctrl = assuan_get_pointer (ctx); + ctrl_t ctrl = assuan_get_pointer (ctx); int n; char *p; unsigned char *buf; - /* FIXME: If we are locked return an error. */ + if (locked_session && locked_session != ctrl->server_local) + return gpg_error (GPG_ERR_EBUSY); /* Parse the hexstring. */ for (p=line,n=0; hexdigitp (p); p++, n++) @@ -700,13 +810,14 @@ pin_cb (void *opaque, const char *info, char **retstr) static int cmd_pksign (assuan_context_t ctx, char *line) { - CTRL ctrl = assuan_get_pointer (ctx); + ctrl_t ctrl = assuan_get_pointer (ctx); int rc; unsigned char *outdata; size_t outdatalen; char *keyidstr; - /* FIXME: If we are locked return an error. */ + if ( IS_LOCKED (ctrl) ) + return gpg_error (GPG_ERR_EBUSY); if ((rc = open_card (ctrl, NULL))) return rc; @@ -753,13 +864,14 @@ cmd_pksign (assuan_context_t ctx, char *line) static int cmd_pkauth (assuan_context_t ctx, char *line) { - CTRL ctrl = assuan_get_pointer (ctx); + ctrl_t ctrl = assuan_get_pointer (ctx); int rc; unsigned char *outdata; size_t outdatalen; char *keyidstr; - /* FIXME: If we are locked return an error. */ + if ( IS_LOCKED (ctrl) ) + return gpg_error (GPG_ERR_EBUSY); if ((rc = open_card (ctrl, NULL))) return rc; @@ -802,13 +914,14 @@ cmd_pkauth (assuan_context_t ctx, char *line) static int cmd_pkdecrypt (assuan_context_t ctx, char *line) { - CTRL ctrl = assuan_get_pointer (ctx); + ctrl_t ctrl = assuan_get_pointer (ctx); int rc; unsigned char *outdata; size_t outdatalen; char *keyidstr; - /* FIXME: If we are locked return an error. */ + if ( IS_LOCKED (ctrl) ) + return gpg_error (GPG_ERR_EBUSY); if ((rc = open_card (ctrl, NULL))) return rc; @@ -861,7 +974,7 @@ cmd_pkdecrypt (assuan_context_t ctx, char *line) static int cmd_getattr (assuan_context_t ctx, char *line) { - CTRL ctrl = assuan_get_pointer (ctx); + ctrl_t ctrl = assuan_get_pointer (ctx); int rc; char *keyword; @@ -900,14 +1013,15 @@ cmd_getattr (assuan_context_t ctx, char *line) static int cmd_setattr (assuan_context_t ctx, char *orig_line) { - CTRL ctrl = assuan_get_pointer (ctx); + ctrl_t ctrl = assuan_get_pointer (ctx); int rc; char *keyword; int keywordlen; size_t nbytes; char *line, *linebuf; - /* FIXME: If we are locked return an error. */ + if ( IS_LOCKED (ctrl) ) + return gpg_error (GPG_ERR_EBUSY); if ((rc = open_card (ctrl, NULL))) return rc; @@ -956,12 +1070,13 @@ cmd_setattr (assuan_context_t ctx, char *orig_line) static int cmd_genkey (assuan_context_t ctx, char *line) { - CTRL ctrl = assuan_get_pointer (ctx); + ctrl_t ctrl = assuan_get_pointer (ctx); int rc; char *keyno; int force = has_option (line, "--force"); - /* FIXME: If we are locked return an error. */ + if ( IS_LOCKED (ctrl) ) + return gpg_error (GPG_ERR_EBUSY); /* Skip over options. */ while ( *line == '-' && line[1] == '-' ) @@ -1004,7 +1119,7 @@ cmd_genkey (assuan_context_t ctx, char *line) static int cmd_random (assuan_context_t ctx, char *line) { - CTRL ctrl = assuan_get_pointer (ctx); + ctrl_t ctrl = assuan_get_pointer (ctx); int rc; size_t nbytes; unsigned char *buffer; @@ -1044,12 +1159,13 @@ cmd_random (assuan_context_t ctx, char *line) static int cmd_passwd (assuan_context_t ctx, char *line) { - CTRL ctrl = assuan_get_pointer (ctx); + ctrl_t ctrl = assuan_get_pointer (ctx); int rc; char *chvnostr; int reset_mode = has_option (line, "--reset"); - /* FIXME: If we are locked return an error. */ + if ( IS_LOCKED (ctrl) ) + return gpg_error (GPG_ERR_EBUSY); /* Skip over options. */ while (*line == '-' && line[1] == '-') @@ -1091,11 +1207,12 @@ cmd_passwd (assuan_context_t ctx, char *line) static int cmd_checkpin (assuan_context_t ctx, char *line) { - CTRL ctrl = assuan_get_pointer (ctx); + ctrl_t ctrl = assuan_get_pointer (ctx); int rc; char *keyidstr; - /* FIXME: If we are locked return an error. */ + if ( IS_LOCKED (ctrl) ) + return gpg_error (GPG_ERR_EBUSY); if ((rc = open_card (ctrl, NULL))) return rc; @@ -1122,15 +1239,83 @@ cmd_checkpin (assuan_context_t ctx, char *line) } +/* LOCK [--wait] + + Grant exclusive card access to this session. Note that there is + no lock counter used and a second lock from the same session will + get ignore. A single unlock (or RESET) unlocks the session. + Return GPG_ERR_EBUSY if another session has locked the reader. + + If the option --wait is given the command will wait until a + lock has been released. + */ +static int +cmd_lock (assuan_context_t ctx, char *line) +{ + ctrl_t ctrl = assuan_get_pointer (ctx); + int rc = 0; + + retry: + if (locked_session) + { + if (locked_session != ctrl->server_local) + rc = gpg_error (GPG_ERR_EBUSY); + } + else + locked_session = ctrl->server_local; + +#ifdef USE_GNU_PTH + if (rc && has_option (line, "--wait")) + { + pth_sleep (1); /* Better implement an event mechanism. However, + for card operations this should be + sufficient. */ + goto retry; + } +#endif /*USE_GNU_PTH*/ + + if (rc) + log_error ("cmd_lock failed: %s\n", gpg_strerror (rc)); + return map_to_assuan_status (rc); +} + + +/* UNLOCK + + Release exclusive card access. + */ +static int +cmd_unlock (assuan_context_t ctx, char *line) +{ + ctrl_t ctrl = assuan_get_pointer (ctx); + int rc = 0; + + if (locked_session) + { + if (locked_session != ctrl->server_local) + rc = gpg_error (GPG_ERR_EBUSY); + else + locked_session = NULL; + } + else + rc = gpg_error (GPG_ERR_NOT_LOCKED); + + if (rc) + log_error ("cmd_unlock failed: %s\n", gpg_strerror (rc)); + return map_to_assuan_status (rc); +} + + + /* Tell the assuan library about our commands */ static int -register_commands (ASSUAN_CONTEXT ctx) +register_commands (assuan_context_t ctx) { static struct { const char *name; - int (*handler)(ASSUAN_CONTEXT, char *line); + int (*handler)(assuan_context_t, char *line); } table[] = { { "SERIALNO", cmd_serialno }, { "LEARN", cmd_learn }, @@ -1148,6 +1333,8 @@ register_commands (ASSUAN_CONTEXT ctx) { "RANDOM", cmd_random }, { "PASSWD", cmd_passwd }, { "CHECKPIN", cmd_checkpin }, + { "LOCK", cmd_lock }, + { "UNLOCK", cmd_unlock }, { NULL } }; int i, rc; @@ -1172,7 +1359,7 @@ void scd_command_handler (int listen_fd) { int rc; - ASSUAN_CONTEXT ctx; + assuan_context_t ctx; struct server_control_s ctrl; memset (&ctrl, 0, sizeof ctrl); @@ -1204,20 +1391,24 @@ scd_command_handler (int listen_fd) scd_exit (2); } assuan_set_pointer (ctx, &ctrl); + + /* Allocate and initialize the server object. Put it into the list + of active sessions. */ ctrl.server_local = xcalloc (1, sizeof *ctrl.server_local); + ctrl.server_local->next_session = session_list; + session_list = ctrl.server_local; + ctrl.server_local->ctrl_backlink = &ctrl; ctrl.server_local->assuan_ctx = ctx; if (DBG_ASSUAN) assuan_set_log_stream (ctx, log_get_stream ()); - /* Store the primary connection's assuan context. */ - if (!primary_connection) - primary_connection = &ctrl; - /* We open the reader right at startup so that the ticker is able to update the status file. */ if (ctrl.reader_slot == -1) - ctrl.reader_slot = apdu_open_reader (opt.reader_port); + { + ctrl.reader_slot = get_reader_slot (); + } /* Command processing loop. */ for (;;) @@ -1241,13 +1432,26 @@ scd_command_handler (int listen_fd) } } - /* The next client will be the primary conenction if this one - terminates. */ - if (primary_connection == &ctrl) - primary_connection = NULL; + /* Cleanup. */ + do_reset (&ctrl, 1); - do_reset (&ctrl, 1); /* Cleanup. */ + /* Release the server object. */ + if (session_list == ctrl.server_local) + session_list = ctrl.server_local->next_session; + else + { + struct server_local_s *sl; + + for (sl=session_list; sl->next_session; sl = sl->next_session) + if (sl->next_session == ctrl.server_local) + break; + if (!sl->next_session) + BUG (); + sl->next_session = ctrl.server_local->next_session; + } + xfree (ctrl.server_local); + /* Release the Assuan context. */ assuan_deinit_server (ctx); } @@ -1256,14 +1460,14 @@ scd_command_handler (int listen_fd) buffers. The variable elements are pairs of (char *, size_t), terminated with a (NULL, 0). */ void -send_status_info (CTRL ctrl, const char *keyword, ...) +send_status_info (ctrl_t ctrl, const char *keyword, ...) { va_list arg_ptr; const unsigned char *value; size_t valuelen; char buf[950], *p; size_t n; - ASSUAN_CONTEXT ctx = ctrl->server_local->assuan_ctx; + assuan_context_t ctx = ctrl->server_local->assuan_ctx; va_start (arg_ptr, keyword); @@ -1299,7 +1503,7 @@ send_status_info (CTRL ctrl, const char *keyword, ...) } -/* This fucntion is called by the ticker thread to check for changes +/* This function is called by the ticker thread to check for changes of the reader stati. It updates the reader status files and if requested by the caller also send a signal to the caller. */ void @@ -1328,6 +1532,7 @@ scd_update_reader_status_file (void) char *fname; char templ[50]; FILE *fp; + struct server_local_s *sl; log_info ("updating status of slot %d to 0x%04X\n", slot, status); @@ -1344,33 +1549,31 @@ scd_update_reader_status_file (void) } xfree (fname); - /* Set the card removed flag. We will set this on any - card change because a reset or SERIALNO request must be - done in any case. */ - if (primary_connection && primary_connection->server_local - && last[slot].any ) - primary_connection->server_local->card_removed = 1; + /* Set the card removed flag for all current sessions. We + will set this on any card change because a reset or + SERIALNO request must be done in any case. */ + if (last[slot].any) + update_card_removed (slot, 1); last[slot].any = 1; last[slot].status = status; last[slot].changed = changed; - /* Send a signal to the primary client, if any. */ - if (primary_connection && primary_connection->server_local - && primary_connection->server_local->assuan_ctx) - { - pid_t pid = assuan_get_pid (primary_connection - ->server_local->assuan_ctx); - int signo = primary_connection->server_local->event_signal; - - log_info ("client pid is %d, sending signal %d\n", pid, signo); + /* Send a signal to all clients who applied for it. */ + for (sl=session_list; sl; sl = sl->next_session) + if (sl->event_signal && sl->assuan_ctx) + { + pid_t pid = assuan_get_pid (sl->assuan_ctx); + int signo = sl->event_signal; + log_info ("client pid is %d, sending signal %d\n", + pid, signo); #ifndef HAVE_W32_SYSTEM - if (pid != (pid_t)(-1) && pid && signo > 0) - kill (pid, signo); + if (pid != (pid_t)(-1) && pid && signo > 0) + kill (pid, signo); #endif - } + } } } } |