Attachment 979 Details for Bug 1090 – rework patch based on comments #2 and #3.

[patch] rework patch based on comments #2 and #3.

openssh-maxsessions.patch (text/plain), 6.94 KB, created by Darren Tucker on 2005-10-03 14:39:00 AEST

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Creator: Darren Tucker

Created: 2005-10-03 14:39:00 AEST

Size: 6.94 KB

patch

obsolete

>Index: servconf.c
>===================================================================
>RCS file: /usr/local/src/security/openssh/cvs/openssh_cvs/servconf.c,v
>retrieving revision 1.134
>diff -u -p -r1.134 servconf.c
>--- servconf.c	12 Aug 2005 12:11:37 -0000	1.134
>+++ servconf.c	3 Oct 2005 03:41:30 -0000
>@@ -98,6 +98,7 @@ initialize_server_options(ServerOptions 
> 	options->use_dns = -1;
> 	options->client_alive_interval = -1;
> 	options->client_alive_count_max = -1;
>+	options->max_sessions = -1;
> 	options->authorized_keys_file = NULL;
> 	options->authorized_keys_file2 = NULL;
> 	options->num_accept_env = 0;
>@@ -220,6 +221,8 @@ fill_default_server_options(ServerOption
> 		options->client_alive_interval = 0;
> 	if (options->client_alive_count_max == -1)
> 		options->client_alive_count_max = 3;
>+	if (options->max_sessions == -1)
>+		options->max_sessions = 64;
> 	if (options->authorized_keys_file2 == NULL) {
> 		/* authorized_keys_file2 falls back to authorized_keys_file */
> 		if (options->authorized_keys_file != NULL)
>@@ -272,6 +275,7 @@ typedef enum {
> 	sClientAliveCountMax, sAuthorizedKeysFile, sAuthorizedKeysFile2,
> 	sGssAuthentication, sGssCleanupCreds, sAcceptEnv,
> 	sUsePrivilegeSeparation,
>+	sMaxSessions,
> 	sDeprecated, sUnsupported
> } ServerOpCodes;
> 
>@@ -373,6 +377,7 @@ static struct {
> 	{ "authorizedkeysfile2", sAuthorizedKeysFile2 },
> 	{ "useprivilegeseparation", sUsePrivilegeSeparation},
> 	{ "acceptenv", sAcceptEnv },
>+	{ "maxsessions", sMaxSessions },
> 	{ NULL, sBadOption }
> };
> 
>@@ -949,6 +954,10 @@ parse_flag:
> 		intptr = &options->client_alive_count_max;
> 		goto parse_int;
> 
>+	case sMaxSessions:
>+		intptr = &options->max_sessions;
>+		goto parse_int;
>+
> 	case sAcceptEnv:
> 		while ((arg = strdelim(&cp)) && *arg != '\0') {
> 			if (strchr(arg, '=') != NULL)
>Index: servconf.h
>===================================================================
>RCS file: /usr/local/src/security/openssh/cvs/openssh_cvs/servconf.h,v
>retrieving revision 1.63
>diff -u -p -r1.63 servconf.h
>--- servconf.h	19 Jan 2005 23:57:56 -0000	1.63
>+++ servconf.h	3 Oct 2005 03:41:30 -0000
>@@ -133,6 +133,7 @@ typedef struct {
> 
> 	char   *authorized_keys_file;	/* File containing public keys */
> 	char   *authorized_keys_file2;
>+	int	max_sessions;		/* Maximum number of sessions */
> 	int	use_pam;		/* Enable auth via PAM */
> }       ServerOptions;
> 
>Index: session.c
>===================================================================
>RCS file: /usr/local/src/security/openssh/cvs/openssh_cvs/session.c,v
>retrieving revision 1.306
>diff -u -p -r1.306 session.c
>--- session.c	31 Aug 2005 16:59:49 -0000	1.306
>+++ session.c	3 Oct 2005 04:33:58 -0000
>@@ -104,8 +104,8 @@ extern Buffer loginmsg;
> const char *original_command = NULL;
> 
> /* data */
>-#define MAX_SESSIONS 10
>-Session	sessions[MAX_SESSIONS];
>+static Session	*sessions = NULL;
>+static int num_sessions = 0;
> 
> #ifdef HAVE_LOGIN_CAP
> login_cap_t *lc;
>@@ -1623,28 +1623,55 @@ Session *
> session_new(void)
> {
> 	int i;
>-	static int did_init = 0;
>-	if (!did_init) {
>+	Session *s = NULL, *n = NULL;
>+
>+	if (sessions == NULL) {
> 		debug("session_new: init");
>-		for (i = 0; i < MAX_SESSIONS; i++) {
>+		sessions = calloc(1, sizeof(sessions[0]));
>+		if (sessions == NULL) {
>+			error("session_new: can't allocate initial session: %s",
>+			    strerror(errno));
>+			return NULL;
>+		}
>+		num_sessions = 1;
>+		for (i = 0; i < num_sessions; i++) {
>+			/* XXX: unnecessary since calloc zeroes? */
> 			sessions[i].used = 0;
> 		}
>-		did_init = 1;
> 	}
>-	for (i = 0; i < MAX_SESSIONS; i++) {
>-		Session *s = &sessions[i];
>-		if (! s->used) {
>-			memset(s, 0, sizeof(*s));
>-			s->chanid = -1;
>-			s->ptyfd = -1;
>-			s->ttyfd = -1;
>-			s->used = 1;
>-			s->self = i;
>-			s->x11_chanids = NULL;
>-			debug("session_new: session %d", i);
>-			return s;
>-		}
>+	for (i = 0; i < num_sessions; i++) {
>+		s = &sessions[i];
>+		if (!s->used)
>+			break;
>+	}
>+	/* if we reached the end of the array and are within limits, expand */
>+	if (num_sessions == i && num_sessions < INT_MAX && \
>+	    (options.max_sessions == 0 ||
>+	    num_sessions < options.max_sessions)) {
>+		debug("session_new: realloc");
>+		n = realloc(sessions, (num_sessions + 1) * sizeof(*sessions));
>+		if (n == NULL) {
>+			error("session_new: realloc sessions failed: %s",
>+			    strerror(errno));
>+			return NULL;
>+		}
>+		sessions = n;
>+		num_sessions++;
>+		s = &sessions[i];
>+		s->used = 0;
>+	}
>+	if (!s->used) {
>+		memset(s, 0, sizeof(*s));
>+		s->chanid = -1;
>+		s->ptyfd = -1;
>+		s->ttyfd = -1;
>+		s->used = 1;
>+		s->self = i;
>+		s->x11_chanids = NULL;
>+		debug("session_new: session %d", i);
>+		return s;
> 	}
>+	debug("session_new: no room");
> 	return NULL;
> }
> 
>@@ -1652,7 +1679,7 @@ static void
> session_dump(void)
> {
> 	int i;
>-	for (i = 0; i < MAX_SESSIONS; i++) {
>+	for (i = 0; i < num_sessions; i++) {
> 		Session *s = &sessions[i];
> 		debug("dump: used %d session %d %p channel %d pid %ld",
> 		    s->used,
>@@ -1685,7 +1712,7 @@ Session *
> session_by_tty(char *tty)
> {
> 	int i;
>-	for (i = 0; i < MAX_SESSIONS; i++) {
>+	for (i = 0; i < num_sessions; i++) {
> 		Session *s = &sessions[i];
> 		if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
> 			debug("session_by_tty: session %d tty %s", i, tty);
>@@ -1701,7 +1728,7 @@ static Session *
> session_by_channel(int id)
> {
> 	int i;
>-	for (i = 0; i < MAX_SESSIONS; i++) {
>+	for (i = 0; i < num_sessions; i++) {
> 		Session *s = &sessions[i];
> 		if (s->used && s->chanid == id) {
> 			debug("session_by_channel: session %d channel %d", i, id);
>@@ -1718,7 +1745,7 @@ session_by_x11_channel(int id)
> {
> 	int i, j;
> 
>-	for (i = 0; i < MAX_SESSIONS; i++) {
>+	for (i = 0; i < num_sessions; i++) {
> 		Session *s = &sessions[i];
> 
> 		if (s->x11_chanids == NULL || !s->used)
>@@ -1741,7 +1768,7 @@ session_by_pid(pid_t pid)
> {
> 	int i;
> 	debug("session_by_pid: pid %ld", (long)pid);
>-	for (i = 0; i < MAX_SESSIONS; i++) {
>+	for (i = 0; i < num_sessions; i++) {
> 		Session *s = &sessions[i];
> 		if (s->used && s->pid == pid)
> 			return s;
>@@ -2283,7 +2310,7 @@ void
> session_destroy_all(void (*closefunc)(Session *))
> {
> 	int i;
>-	for (i = 0; i < MAX_SESSIONS; i++) {
>+	for (i = 0; i < num_sessions; i++) {
> 		Session *s = &sessions[i];
> 		if (s->used) {
> 			if (closefunc != NULL)
>@@ -2302,7 +2329,7 @@ session_tty_list(void)
> 	char *cp;
> 
> 	buf[0] = '\0';
>-	for (i = 0; i < MAX_SESSIONS; i++) {
>+	for (i = 0; i < num_sessions; i++) {
> 		Session *s = &sessions[i];
> 		if (s->used && s->ttyfd != -1) {
> 
>Index: sshd_config.5
>===================================================================
>RCS file: /usr/local/src/security/openssh/cvs/openssh_cvs/sshd_config.5,v
>retrieving revision 1.49
>diff -u -p -r1.49 sshd_config.5
>--- sshd_config.5	26 Jul 2005 11:54:57 -0000	1.49
>+++ sshd_config.5	3 Oct 2005 03:42:21 -0000
>@@ -439,6 +439,9 @@ connection.
> Once the number of failures reaches half this value,
> additional failures are logged.
> The default is 6.
>+.It Cm MaxSessions
>+Defines the maximum number of sessions that a server will permit.
>+The default is 64.
> .It Cm MaxStartups
> Specifies the maximum number of concurrent unauthenticated connections to the
> .Nm sshd

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Attachments on bug 1090: 963 | 979 | 1473 | 1483