Rationalise access to, and content of, backends[] array.

Should be no significant change in behaviour.
(Well, entering usernames containing commas on Plink's command line will be
a little harder now.)

[originally from svn r7628]

be_all.c

@@ -22,10 +22,10 @@ const int be_default_protocol = PROT_TELNET;
 const int be_default_protocol = PROT_SSH;
 #endif
 
-struct backend_list backends[] = {
+Backend *backends[] = {
-    {PROT_SSH, "ssh", &ssh_backend},
+    &ssh_backend,
-    {PROT_TELNET, "telnet", &telnet_backend},
+    &telnet_backend,
-    {PROT_RLOGIN, "rlogin", &rlogin_backend},
+    &rlogin_backend,
-    {PROT_RAW, "raw", &raw_backend},
+    &raw_backend,
-    {0, NULL}
+    NULL
 };

be_all_s.c

@@ -22,11 +22,11 @@ const int be_default_protocol = PROT_TELNET;
 const int be_default_protocol = PROT_SSH;
 #endif
 
-struct backend_list backends[] = {
+Backend *backends[] = {
-    {PROT_SSH, "ssh", &ssh_backend},
+    &ssh_backend,
-    {PROT_TELNET, "telnet", &telnet_backend},
+    &telnet_backend,
-    {PROT_RLOGIN, "rlogin", &rlogin_backend},
+    &rlogin_backend,
-    {PROT_RAW, "raw", &raw_backend},
+    &raw_backend,
-    {PROT_SERIAL, "serial", &serial_backend},
+    &serial_backend,
-    {0, NULL}
+    NULL
 };

be_none.c

@@ -1,16 +1,11 @@
 /*
- * Linking module for PSCP: list the available backends, but
+ * Linking module for programs that do not support selection of backend
- * without accompanying function suites. Used only for name
+ * (such as pscp or pterm).
- * lookups.
  */
 
 #include <stdio.h>
 #include "putty.h"
 
-struct backend_list backends[] = {
+Backend *backends[] = {
-    {PROT_SSH, "ssh", NULL},
+    NULL
-    {PROT_TELNET, "telnet", NULL},
-    {PROT_RLOGIN, "rlogin", NULL},
-    {PROT_RAW, "raw", NULL},
-    {0, NULL}
 };

be_nos_s.c

@@ -10,12 +10,12 @@ const int be_default_protocol = PROT_TELNET;
 
 const char *const appname = "PuTTYtel";
 
-struct backend_list backends[] = {
+Backend *backends[] = {
-    {PROT_TELNET, "telnet", &telnet_backend},
+    &telnet_backend,
-    {PROT_RLOGIN, "rlogin", &rlogin_backend},
+    &rlogin_backend,
-    {PROT_RAW, "raw", &raw_backend},
+    &raw_backend,
-    {PROT_SERIAL, "serial", &serial_backend},
+    &serial_backend,
-    {0, NULL}
+    NULL
 };
 
 /*

be_nossh.c

@@ -10,11 +10,11 @@ const int be_default_protocol = PROT_TELNET;
 
 const char *const appname = "PuTTYtel";
 
-struct backend_list backends[] = {
+Backend *backends[] = {
-    {PROT_TELNET, "telnet", &telnet_backend},
+    &telnet_backend,
-    {PROT_RLOGIN, "rlogin", &rlogin_backend},
+    &rlogin_backend,
-    {PROT_RAW, "raw", &raw_backend},
+    &raw_backend,
-    {0, NULL}
+    NULL
 };
 
 /*

config.c

@@ -15,20 +15,6 @@
 #define HOST_BOX_TITLE "Host Name (or IP address)"
 #define PORT_BOX_TITLE "Port"
 
-/*
- * Convenience function: determine whether this binary supports a
- * given backend.
- */
-static int have_backend(int protocol)
-{
-    struct backend_list *p = backends;
-    for (p = backends; p->name; p++) {
-	if (p->protocol == protocol)
-	    return 1;
-    }
-    return 0;
-}
-
 static void config_host_handler(union control *ctrl, void *dlg,
 				void *data, int event)
 {
@@ -1166,7 +1152,7 @@ void setup_config_box(struct controlbox *b, int midsession,
 	hp->port = c;
 	ctrl_columns(s, 1, 100);
 
-	if (!have_backend(PROT_SSH)) {
+	if (!backend_from_proto(PROT_SSH)) {
 	    ctrl_radiobuttons(s, "Connection type:", NO_SHORTCUT, 3,
 			      HELPCTX(session_hostname),
 			      config_protocolbuttons_handler, P(hp),
@@ -1257,7 +1243,7 @@ void setup_config_box(struct controlbox *b, int midsession,
     {
 	char *sshlogname, *sshrawlogname;
 	if ((midsession && protocol == PROT_SSH) ||
-	    (!midsession && have_backend(PROT_SSH))) {
+	    (!midsession && backend_from_proto(PROT_SSH))) {
 	    sshlogname = "SSH packets";
 	    sshrawlogname = "SSH packets and raw data";
         } else {
@@ -1293,7 +1279,7 @@ void setup_config_box(struct controlbox *b, int midsession,
 		 dlg_stdcheckbox_handler, I(offsetof(Config,logflush)));
 
     if ((midsession && protocol == PROT_SSH) ||
-	(!midsession && have_backend(PROT_SSH))) {
+	(!midsession && backend_from_proto(PROT_SSH))) {
 	s = ctrl_getset(b, "Session/Logging", "ssh",
 			"Options specific to SSH packet logging");
 	ctrl_checkbox(s, "Omit known password fields", 'k',
@@ -1912,7 +1898,7 @@ void setup_config_box(struct controlbox *b, int midsession,
      * when we're not doing SSH.
      */
 
-    if (have_backend(PROT_SSH) && (!midsession || protocol == PROT_SSH)) {
+    if (backend_from_proto(PROT_SSH) && (!midsession || protocol == PROT_SSH)) {
 
 	/*
 	 * The Connection/SSH panel.

mac/mac.c

@@ -210,13 +210,10 @@ static void mac_startup(void) {
     default_protocol = be_default_protocol;
     /* Find the appropriate default port. */
     {
-	int i;
+	Backend *b = backend_from_proto(default_protocol);
 	default_port = 0; /* illegal */
-	for (i = 0; backends[i].backend != NULL; i++)
+	if (b)
-	    if (backends[i].protocol == default_protocol) {
+	    default_port = b->default_port;
-		default_port = backends[i].backend->default_port;
-		break;
-	    }
     }
     flags = FLAG_INTERACTIVE;
 

mac/macterm.c

@@ -115,12 +115,7 @@ void mac_startsession(Session *s)
      * Select protocol. This is farmed out into a table in a
      * separate file to enable an ssh-free variant.
      */
-    s->back = NULL;
+    s->back = backend_from_proto(s->cfg.protocol);
-    for (i = 0; backends[i].backend != NULL; i++)
-	if (backends[i].protocol == s->cfg.protocol) {
-	    s->back = backends[i].backend;
-	    break;
-	}
     if (s->back == NULL)
 	fatalbox("Unsupported protocol number found");
 

macosx/osxwin.m

@@ -232,15 +232,9 @@
     /*
      * Set up a backend.
      */
-    {
+    back = backend_from_proto(cfg.protocol);
-	int i;
+    if (!back)
 	back = &pty_backend;
-	for (i = 0; backends[i].backend != NULL; i++)
-	    if (backends[i].protocol == cfg.protocol) {
-		back = backends[i].backend;
-		break;
-	    }
-    }
 
     {
 	const char *error;

putty.h

@@ -389,14 +389,12 @@ struct backend_tag {
      */
     void (*unthrottle) (void *handle, int);
     int (*cfg_info) (void *handle);
+    char *name;
+    int protocol;
     int default_port;
 };
 
-extern struct backend_list {
+extern Backend *backends[];
-    int protocol;
-    char *name;
-    Backend *backend;
-} backends[];
 
 /*
  * Suggested default protocol provided by the backend link module.
@@ -778,6 +776,8 @@ void random_destroy_seed(void);
 /*
  * Exports from settings.c.
  */
+Backend *backend_from_name(const char *name);
+Backend *backend_from_proto(int proto);
 char *save_settings(char *section, Config * cfg);
 void save_open_settings(void *sesskey, Config *cfg);
 void load_settings(char *section, Config * cfg);

raw.c

@@ -278,5 +278,7 @@ Backend raw_backend = {
     raw_provide_logctx,
     raw_unthrottle,
     raw_cfg_info,
+    "raw",
+    PROT_RAW,
     1
 };

rlogin.c

@@ -349,5 +349,7 @@ Backend rlogin_backend = {
     rlogin_provide_logctx,
     rlogin_unthrottle,
     rlogin_cfg_info,
+    "rlogin",
+    PROT_RLOGIN,
     1
 };

settings.c

@@ -52,6 +52,29 @@ const char *const ttymodes[] = {
     "CS8",	"PARENB",   "PARODD",	NULL
 };
 
+/*
+ * Convenience functions to access the backends[] array
+ * (which is only present in tools that manage settings).
+ */
+
+Backend *backend_from_name(const char *name)
+{
+    Backend **p;
+    for (p = backends; *p != NULL; p++)
+	if (!strcmp((*p)->name, name))
+	    return *p;
+    return NULL;
+}
+
+Backend *backend_from_proto(int proto)
+{
+    Backend **p;
+    for (p = backends; *p != NULL; p++)
+	if ((*p)->protocol == proto)
+	    return *p;
+    return NULL;
+}
+
 static void gpps(void *handle, const char *name, const char *def,
 		 char *val, int len)
 {
@@ -259,11 +282,11 @@ void save_open_settings(void *sesskey, Config *cfg)
     write_setting_i(sesskey, "SSHLogOmitPasswords", cfg->logomitpass);
     write_setting_i(sesskey, "SSHLogOmitData", cfg->logomitdata);
     p = "raw";
-    for (i = 0; backends[i].name != NULL; i++)
+    {
-	if (backends[i].protocol == cfg->protocol) {
+	const Backend *b = backend_from_proto(cfg->protocol);
-	    p = backends[i].name;
+	if (b)
-	    break;
+	    p = b->name;
-	}
+    }
     write_setting_s(sesskey, "Protocol", p);
     write_setting_i(sesskey, "PortNumber", cfg->port);
     /* The CloseOnExit numbers are arranged in a different order from
@@ -476,12 +499,13 @@ void load_open_settings(void *sesskey, Config *cfg)
     gpps(sesskey, "Protocol", "default", prot, 10);
     cfg->protocol = default_protocol;
     cfg->port = default_port;
-    for (i = 0; backends[i].name != NULL; i++)
+    {
-	if (!strcmp(prot, backends[i].name)) {
+	const Backend *b = backend_from_name(prot);
-	    cfg->protocol = backends[i].protocol;
+	if (b) {
+	    cfg->protocol = b->protocol;
 	    gppi(sesskey, "PortNumber", default_port, &cfg->port);
-	    break;
 	}
+    }
 
     /* Address family selection */
     gppi(sesskey, "AddressFamily", ADDRTYPE_UNSPEC, &cfg->addressfamily);

ssh.c

@@ -9146,5 +9146,7 @@ Backend ssh_backend = {
     ssh_provide_logctx,
     ssh_unthrottle,
     ssh_cfg_info,
+    "ssh",
+    PROT_SSH,
     22
 };

telnet.c

@@ -1106,5 +1106,7 @@ Backend telnet_backend = {
     telnet_provide_logctx,
     telnet_unthrottle,
     telnet_cfg_info,
+    "telnet",
+    PROT_TELNET,
     23
 };

testback.c

@@ -59,14 +59,14 @@ Backend null_backend = {
     null_init, null_free, null_reconfig, null_send, null_sendbuffer, null_size,
     null_special, null_get_specials, null_connected, null_exitcode, null_sendok,
     null_ldisc, null_provide_ldisc, null_provide_logctx, null_unthrottle,
-    null_cfg_info, 0
+    null_cfg_info, "null", -1, 0
 };
 
 Backend loop_backend = {
     loop_init, loop_free, null_reconfig, loop_send, null_sendbuffer, null_size,
     null_special, null_get_specials, null_connected, null_exitcode, null_sendok,
     null_ldisc, null_provide_ldisc, null_provide_logctx, null_unthrottle,
-    null_cfg_info, 0
+    null_cfg_info, "loop", -1, 0
 };
 
 struct loop_state {

unix/uxplink.c

@@ -596,15 +596,11 @@ int main(int argc, char **argv)
 	 * Override the default protocol if PLINK_PROTOCOL is set.
 	 */
 	char *p = getenv("PLINK_PROTOCOL");
-	int i;
 	if (p) {
-	    for (i = 0; backends[i].backend != NULL; i++) {
+	    const Backend *b = backend_from_name(p);
-		if (!strcmp(backends[i].name, p)) {
+	    if (b) {
-		    default_protocol = cfg.protocol = backends[i].protocol;
+		default_protocol = cfg.protocol = b->protocol;
-		    default_port = cfg.port =
+		default_port = cfg.port = b->default_port;
-			backends[i].backend->default_port;
-		    break;
-		}
 	    }
 	}
     }
@@ -681,19 +677,14 @@ int main(int argc, char **argv)
 		     */
 		    r = strchr(p, ',');
 		    if (r) {
-			int i, j;
+			const Backend *b;
-			for (i = 0; backends[i].backend != NULL; i++) {
+			*r = '\0';
-			    j = strlen(backends[i].name);
+			b = backend_from_name(p);
-			    if (j == r - p &&
+			if (b) {
-				!memcmp(backends[i].name, p, j)) {
+			    default_protocol = cfg.protocol = b->protocol;
-				default_protocol = cfg.protocol =
+			    portnumber = b->default_port;
-				    backends[i].protocol;
-				portnumber =
-				    backends[i].backend->default_port;
-				p = r + 1;
-				break;
-			    }
 			}
+			p = r + 1;
 		    }
 
 		    /*
@@ -836,19 +827,11 @@ int main(int argc, char **argv)
      * Select protocol. This is farmed out into a table in a
      * separate file to enable an ssh-free variant.
      */
-    {
+    back = backend_from_proto(cfg.protocol);
-	int i;
+    if (back == NULL) {
-	back = NULL;
+	fprintf(stderr,
-	for (i = 0; backends[i].backend != NULL; i++)
+		"Internal fault: Unsupported protocol found\n");
-	    if (backends[i].protocol == cfg.protocol) {
+	return 1;
-		back = backends[i].backend;
-		break;
-	    }
-	if (back == NULL) {
-	    fprintf(stderr,
-		    "Internal fault: Unsupported protocol found\n");
-	    return 1;
-	}
     }
 
     /*

unix/uxpty.c

@@ -1085,5 +1085,7 @@ Backend pty_backend = {
     pty_provide_logctx,
     pty_unthrottle,
     pty_cfg_info,
+    "pty",
+    -1,
     1
 };

unix/uxputty.c

@@ -33,13 +33,7 @@ void cleanup_exit(int code)
 
 Backend *select_backend(Config *cfg)
 {
-    int i;
+    Backend *back = backend_from_proto(cfg->protocol);
-    Backend *back = NULL;
-    for (i = 0; backends[i].backend != NULL; i++)
-	if (backends[i].protocol == cfg->protocol) {
-	    back = backends[i].backend;
-	    break;
-	}
     assert(back != NULL);
     return back;
 }
@@ -137,13 +131,10 @@ int main(int argc, char **argv)
     default_protocol = be_default_protocol;
     /* Find the appropriate default port. */
     {
-	int i;
+	Backend *b = backend_from_proto(default_protocol);
 	default_port = 0; /* illegal */
-	for (i = 0; backends[i].backend != NULL; i++)
+	if (b)
-	    if (backends[i].protocol == default_protocol) {
+	    default_port = b->default_port;
-		default_port = backends[i].backend->default_port;
-		break;
-	    }
     }
     return pt_main(argc, argv);
 }

unix/uxser.c

@@ -536,5 +536,7 @@ Backend serial_backend = {
     serial_provide_logctx,
     serial_unthrottle,
     serial_cfg_info,
+    "serial",
+    PROT_SERIAL,
     1
 };

windows/window.c

@@ -219,12 +219,7 @@ static void start_backend(void)
      * Select protocol. This is farmed out into a table in a
      * separate file to enable an ssh-free variant.
      */
-    back = NULL;
+    back = backend_from_proto(cfg.protocol);
-    for (i = 0; backends[i].backend != NULL; i++)
-	if (backends[i].protocol == cfg.protocol) {
-	    back = backends[i].backend;
-	    break;
-	}
     if (back == NULL) {
 	char *str = dupprintf("%s Internal Error", appname);
 	MessageBox(NULL, "Unsupported protocol number found",
@@ -369,13 +364,10 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
 	default_protocol = be_default_protocol;
 	/* Find the appropriate default port. */
 	{
-	    int i;
+	    Backend *b = backend_from_proto(default_protocol);
 	    default_port = 0; /* illegal */
-	    for (i = 0; backends[i].backend != NULL; i++)
+	    if (b)
-		if (backends[i].protocol == default_protocol) {
+		default_port = b->default_port;
-		    default_port = backends[i].backend->default_port;
-		    break;
-		}
 	}
 	cfg.logtype = LGTYP_NONE;
 

windows/winplink.c

@@ -307,13 +307,10 @@ int main(int argc, char **argv)
 	char *p = getenv("PLINK_PROTOCOL");
 	int i;
 	if (p) {
-	    for (i = 0; backends[i].backend != NULL; i++) {
+	    const Backend *b = backend_from_name(p);
-		if (!strcmp(backends[i].name, p)) {
+	    if (b) {
-		    default_protocol = cfg.protocol = backends[i].protocol;
+		default_protocol = cfg.protocol = b->protocol;
-		    default_port = cfg.port =
+		default_port = cfg.port = b->default_port;
-			backends[i].backend->default_port;
-		    break;
-		}
 	    }
 	}
     }
@@ -380,19 +377,14 @@ int main(int argc, char **argv)
 		     */
 		    r = strchr(p, ',');
 		    if (r) {
-			int i, j;
+			const Backend *b;
-			for (i = 0; backends[i].backend != NULL; i++) {
+			*r = '\0';
-			    j = strlen(backends[i].name);
+			b = backend_from_name(p);
-			    if (j == r - p &&
+			if (b) {
-				!memcmp(backends[i].name, p, j)) {
+			    default_protocol = cfg.protocol = b->protocol;
-				default_protocol = cfg.protocol =
+			    portnumber = b->default_port;
-				    backends[i].protocol;
-				portnumber =
-				    backends[i].backend->default_port;
-				p = r + 1;
-				break;
-			    }
 			}
+			p = r + 1;
 		    }
 
 		    /*
@@ -535,19 +527,11 @@ int main(int argc, char **argv)
      * Select protocol. This is farmed out into a table in a
      * separate file to enable an ssh-free variant.
      */
-    {
+    back = backend_from_proto(cfg.protocol);
-	int i;
+    if (back == NULL) {
-	back = NULL;
+	fprintf(stderr,
-	for (i = 0; backends[i].backend != NULL; i++)
+		"Internal fault: Unsupported protocol found\n");
-	    if (backends[i].protocol == cfg.protocol) {
+	return 1;
-		back = backends[i].backend;
-		break;
-	    }
-	if (back == NULL) {
-	    fprintf(stderr,
-		    "Internal fault: Unsupported protocol found\n");
-	    return 1;
-	}
     }
 
     /*

windows/winser.c

@@ -454,5 +454,7 @@ Backend serial_backend = {
     serial_provide_logctx,
     serial_unthrottle,
     serial_cfg_info,
+    "serial",
+    PROT_SERIAL,
     1
 };