Pointer parameter could be declared as pointing to const (callback)

channel.h

@@ -84,7 +84,7 @@ struct Channel {
 	int flushing;
 	/* Used by client chansession to handle ~ escaping, NULL ignored otherwise */
-	void (*read_mangler)(struct Channel*, unsigned char* bytes, int *len);
+	void (*read_mangler)(const struct Channel*, const unsigned char* bytes, int *len);
 	const struct ChanType* type;
@@ -98,7 +98,7 @@ struct ChanType {
 	int (*inithandler)(struct Channel*);
 	int (*check_close)(struct Channel*);
 	void (*reqhandler)(struct Channel*);
-	void (*closehandler)(struct Channel*);
+	void (*closehandler)(const struct Channel*);
 };
 /* Callback for connect_remote */

cli-chansession.c

@@ -35,12 +35,12 @@
 #include "chansession.h"
 #include "agentfwd.h"
-static void cli_closechansess(struct Channel *channel);
+static void cli_closechansess(const struct Channel *channel);
 static int cli_initchansess(struct Channel *channel);
 static void cli_chansessreq(struct Channel *channel);
 static void send_chansess_pty_req(const struct Channel *channel);
 static void send_chansess_shell_req(const struct Channel *channel);
-static void cli_escape_handler(struct Channel *channel, unsigned char* buf, int *len);
+static void cli_escape_handler(const struct Channel *channel, const unsigned char* buf, int *len);
 static int cli_init_netcat(struct Channel *channel);
 static void cli_tty_setup(void);
@@ -83,7 +83,7 @@ out:
 	
 /* If the main session goes, we close it up */
-static void cli_closechansess(struct Channel *UNUSED(channel)) {
+static void cli_closechansess(const struct Channel *UNUSED(channel)) {
 	cli_tty_cleanup(); /* Restore tty modes etc */
 	/* This channel hasn't gone yet, so we have > 1 */
@@ -452,7 +452,7 @@ do_escape(unsigned char c) {
 }
 static
-void cli_escape_handler(struct Channel* UNUSED(channel), unsigned char* buf, int *len) {
+void cli_escape_handler(const struct Channel* UNUSED(channel), const unsigned char* buf, int *len) {
 	char c;
 	int skip_char = 0;

cli-main.c

@@ -142,7 +142,7 @@ static void cli_dropbear_log(int priority,
 	fflush(stderr);
 }
-static void exec_proxy_cmd(void *user_data_cmd) {
+static void exec_proxy_cmd(const void *user_data_cmd) {
 	const char *cmd = user_data_cmd;
 	char *usershell;

dbutil.c

@@ -241,7 +241,7 @@ int connect_unix(const char* path) {
  * it will be run after the child has fork()ed, and is passed exec_data.
  * If ret_errfd == NULL then stderr will not be captured.
  * ret_pid can be passed as  NULL to discard the pid. */
-int spawn_command(void(*exec_fn)(void *user_data), void *exec_data,
+int spawn_command(void(*exec_fn)(const void *user_data), const void *exec_data,
 		int *ret_writefd, int *ret_readfd, int *ret_errfd, pid_t *ret_pid) {
 	int infds[2];
 	int outfds[2];

dbutil.h

@@ -56,7 +56,7 @@ extern int debug_trace;
 char * stripcontrol(const char * text);
-int spawn_command(void(*exec_fn)(void *user_data), void *exec_data,
+int spawn_command(void(*exec_fn)(const void *user_data), const void *exec_data,
 		int *writefd, int *readfd, int *errfd, pid_t *pid);
 void run_shell_command(const char* cmd, unsigned int maxfd, char* usershell);
 #ifdef ENABLE_CONNECT_UNIX

listener.c

@@ -78,8 +78,8 @@ void handle_listeners(const fd_set * readfds) {
  * cleanup(void* typedata) happens when cleaning up */
 struct Listener* new_listener(const int socks[], unsigned int nsocks,
 		int type, void* typedata, 
-		void (*acceptor)(struct Listener* listener, int sock), 
-		void (*cleanup)(struct Listener*)) {
+		void (*acceptor)(const struct Listener* listener, int sock),
+		void (*cleanup)(const struct Listener*)) {
 	unsigned int i, j;
 	struct Listener *newlisten = NULL;
@@ -132,8 +132,8 @@ struct Listener* new_listener(const int socks[], unsigned int nsocks,
 /* Return the first listener which matches the type-specific comparison
  * function. Particularly needed for global requests, like tcp */
-struct Listener * get_listener(int type, void* typedata,
-		int (*match)(void*, void*)) {
+struct Listener * get_listener(int type, const void* typedata,
+		int (*match)(const void*, const void*)) {
 	unsigned int i;
 	struct Listener* listener;

listener.h

@@ -35,8 +35,8 @@ struct Listener {
 	int index; /* index in the array of listeners */
-	void (*acceptor)(struct Listener*, int sock);
-	void (*cleanup)(struct Listener*);
+	void (*acceptor)(const struct Listener*, int sock);
+	void (*cleanup)(const struct Listener*);
 	int type; /* CHANNEL_ID_X11, CHANNEL_ID_AGENT, 
 				 CHANNEL_ID_TCPDIRECT (for clients),
@@ -52,11 +52,11 @@ void set_listener_fds(fd_set * readfds);
 struct Listener* new_listener(const int socks[], unsigned int nsocks,
 		int type, void* typedata, 
-		void (*acceptor)(struct Listener* listener, int sock), 
-		void (*cleanup)(struct Listener*));
-struct Listener * get_listener(int type, void* typedata,
-		int (*match)(void*, void*));
+		void (*acceptor)(const struct Listener* listener, int sock),
+		void (*cleanup)(const struct Listener*));
+struct Listener * get_listener(int type, const void* typedata,
+		int (*match)(const void*, const void*));
 void remove_listener(struct Listener* listener);

svr-agentfwd.c

@@ -45,7 +45,7 @@
 static int send_msg_channel_open_agent(int fd);
 static int bindagent(int fd, struct ChanSess * chansess);
-static void agentaccept(struct Listener * listener, int sock);
+static void agentaccept(const struct Listener * listener, int sock);
 /* Handles client requests to start agent forwarding, sets up listening socket.
  * Returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
@@ -100,7 +100,7 @@ fail:
 /* accepts a connection on the forwarded socket and opens a new channel for it
  * back to the client */
 /* returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
-static void agentaccept(struct Listener *UNUSED(listener), int sock) {
+static void agentaccept(const struct Listener *UNUSED(listener), int sock) {
 	int fd;

svr-chansession.c

@@ -47,10 +47,10 @@ static int sessionsignal(const struct ChanSess *chansess);
 static int noptycommand(struct Channel *channel, struct ChanSess *chansess);
 static int ptycommand(struct Channel *channel, struct ChanSess *chansess);
 static int sessionwinchange(const struct ChanSess *chansess);
-static void execchild(void *user_data_chansess);
+static void execchild(const void *user_data_chansess);
 static void addchildpid(struct ChanSess *chansess, pid_t pid);
 static void sesssigchild_handler(int val);
-static void closechansess(struct Channel *channel);
+static void closechansess(const struct Channel *channel);
 static int newchansess(struct Channel *channel);
 static void chansessionrequest(struct Channel *channel);
 static int sesscheckclose(const struct Channel *channel);
@@ -281,7 +281,7 @@ chansess_login_alloc(const struct ChanSess *chansess) {
 }
 /* clean a session channel */
-static void closechansess(struct Channel *channel) {
+static void closechansess(const struct Channel *channel) {
 	struct ChanSess *chansess;
 	unsigned int i;
@@ -898,7 +898,7 @@ static void addchildpid(struct ChanSess *chansess, pid_t pid) {
 /* Clean up, drop to user privileges, set up the environment and execute
  * the command/shell. This function does not return. */
-static void execchild(void *user_data) {
+static void execchild(const void *user_data) {
 	struct ChanSess *chansess = user_data;
 	char *usershell = NULL;

svr-tcpfwd.c

@@ -107,7 +107,7 @@ out:
 	TRACE(("leave recv_msg_global_request"))
 }
-static int matchtcp(void* typedata1, void* typedata2) {
+static int matchtcp(const void* typedata1, const void* typedata2) {
 	const struct TCPListener *info1 = (struct TCPListener*)typedata1;
 	const struct TCPListener *info2 = (struct TCPListener*)typedata2;

svr-x11fwd.c

@@ -38,7 +38,7 @@
 #define X11BASEPORT 6000
 #define X11BINDBASE 6010
-static void x11accept(struct Listener* listener, int sock);
+static void x11accept(const struct Listener* listener, int sock);
 static int bindport(int fd);
 static int send_msg_channel_open_x11(int fd, const struct sockaddr_in* addr);
@@ -126,7 +126,7 @@ fail:
 /* accepts a new X11 socket */
 /* returns DROPBEAR_FAILURE or DROPBEAR_SUCCESS */
-static void x11accept(struct Listener* listener, int sock) {
+static void x11accept(const struct Listener* listener, int sock) {
 	int fd;
 	struct sockaddr_in addr;

tcp-accept.c

@@ -35,7 +35,7 @@
 #if DROPBEAR_TCP_ACCEPT
-static void cleanup_tcp(struct Listener *listener) {
+static void cleanup_tcp(const struct Listener *listener) {
 	struct TCPListener *tcpinfo = (struct TCPListener*)(listener->typedata);
@@ -52,7 +52,7 @@ int tcp_prio_inithandler(struct Channel* channel)
 	return 0;
 }
-static void tcp_acceptor(struct Listener *listener, int sock) {
+static void tcp_acceptor(const struct Listener *listener, int sock) {
 	int fd;
 	struct sockaddr_storage sa;