]> andersk Git - openssh.git/blobdiff - serverloop.c
- (djm) Stop shadow expiry checking from preventing logins with NIS. Based
[openssh.git] / serverloop.c
index 1a76b8da808b5af935c471bbf87a776f0b4f344e..311a285c3541354cdf8d174c9dd7c3b33b4e2021 100644 (file)
@@ -23,6 +23,7 @@
 #include "ssh2.h"
 #include "session.h"
 #include "dispatch.h"
+#include "auth-options.h"
 
 static Buffer stdin_buffer;    /* Buffer for stdin data. */
 static Buffer stdout_buffer;   /* Buffer for stdout data. */
@@ -85,7 +86,6 @@ sigchld_handler2(int sig)
        int save_errno = errno;
        debug("Received SIGCHLD.");
        child_terminated = 1;
-       signal(SIGCHLD, sigchld_handler2);
        errno = save_errno;
 }
 
@@ -165,33 +165,37 @@ retry_select:
 
        /* Initialize select() masks. */
        FD_ZERO(readset);
+       FD_ZERO(writeset);
 
-       /*
-        * Read packets from the client unless we have too much buffered
-        * stdin or channel data.
-        */
        if (compat20) {
-               // wrong: bad conditionXXX
+               /* wrong: bad condition XXX */
                if (channel_not_very_much_buffered_data())
                        FD_SET(connection_in, readset);
        } else {
-               if (buffer_len(&stdin_buffer) < 4096 &&
+               /*
+                * Read packets from the client unless we have too much
+                * buffered stdin or channel data.
+                */
+               if (buffer_len(&stdin_buffer) < buffer_high &&
                    channel_not_very_much_buffered_data())
                        FD_SET(connection_in, readset);
+               /*
+                * If there is not too much data already buffered going to
+                * the client, try to get some more data from the program.
+                */
+               if (packet_not_very_much_data_to_write()) {
+                       if (!fdout_eof)
+                               FD_SET(fdout, readset);
+                       if (!fderr_eof)
+                               FD_SET(fderr, readset);
+               }
+               /*
+                * If we have buffered data, try to write some of that data
+                * to the program.
+                */
+               if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
+                       FD_SET(fdin, writeset);
        }
-
-       /*
-        * If there is not too much data already buffered going to the
-        * client, try to get some more data from the program.
-        */
-       if (!compat20 && packet_not_very_much_data_to_write()) {
-               if (!fdout_eof)
-                       FD_SET(fdout, readset);
-               if (!fderr_eof)
-                       FD_SET(fderr, readset);
-       }
-       FD_ZERO(writeset);
-
        /* Set masks for channel descriptors. */
        channel_prepare_select(readset, writeset);
 
@@ -202,11 +206,6 @@ retry_select:
        if (packet_have_data_to_write())
                FD_SET(connection_out, writeset);
 
-       /* If we have buffered data, try to write some of that data to the
-          program. */
-       if (!compat20 && fdin != -1 && buffer_len(&stdin_buffer) > 0)
-               FD_SET(fdin, writeset);
-
        /* Update the maximum descriptor number if appropriate. */
        if (channel_max_fd() > max_fd)
                max_fd = channel_max_fd();
@@ -259,20 +258,15 @@ process_input(fd_set * readset)
                if (len == 0) {
                        verbose("Connection closed by remote host.");
                        fatal_cleanup();
+               } else if (len < 0) {
+                       if (errno != EINTR && errno != EAGAIN) {
+                               verbose("Read error from remote host: %.100s", strerror(errno));
+                               fatal_cleanup();
+                       }
+               } else {
+                       /* Buffer any received data. */
+                       packet_process_incoming(buf, len);
                }
-               /*
-                * There is a kernel bug on Solaris that causes select to
-                * sometimes wake up even though there is no data available.
-                */
-               if (len < 0 && errno == EAGAIN)
-                       len = 0;
-
-               if (len < 0) {
-                       verbose("Read error from remote host: %.100s", strerror(errno));
-                       fatal_cleanup();
-               }
-               /* Buffer any received data. */
-               packet_process_incoming(buf, len);
        }
        if (compat20)
                return;
@@ -280,9 +274,11 @@ process_input(fd_set * readset)
        /* Read and buffer any available stdout data from the program. */
        if (!fdout_eof && FD_ISSET(fdout, readset)) {
                len = read(fdout, buf, sizeof(buf));
-               if (len <= 0)
+               if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
+                       /* do nothing */
+               } else if (len <= 0) {
                        fdout_eof = 1;
-               else {
+               else {
                        buffer_append(&stdout_buffer, buf, len);
                        fdout_bytes += len;
                }
@@ -290,10 +286,13 @@ process_input(fd_set * readset)
        /* Read and buffer any available stderr data from the program. */
        if (!fderr_eof && FD_ISSET(fderr, readset)) {
                len = read(fderr, buf, sizeof(buf));
-               if (len <= 0)
+               if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
+                       /* do nothing */
+               } else if (len <= 0) {
                        fderr_eof = 1;
-               else
+               } else {
                        buffer_append(&stderr_buffer, buf, len);
+               }
        }
 }
 
@@ -309,7 +308,9 @@ process_output(fd_set * writeset)
        if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
                len = write(fdin, buffer_ptr(&stdin_buffer),
                    buffer_len(&stdin_buffer));
-               if (len <= 0) {
+               if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
+                       /* do nothing */
+               } else if (len <= 0) {
 #ifdef USE_PIPES
                        close(fdin);
 #else
@@ -376,6 +377,7 @@ process_buffered_input_packets()
 void
 server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
 {
+       fd_set readset, writeset;
        int wait_status;        /* Status returned by wait(). */
        pid_t wait_pid;         /* pid returned by wait(). */
        int waiting_termination = 0;    /* Have displayed waiting close message. */
@@ -396,6 +398,14 @@ server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
        fdin = fdin_arg;
        fdout = fdout_arg;
        fderr = fderr_arg;
+
+       /* nonblocking IO */
+       set_nonblock(fdin);
+       set_nonblock(fdout);
+       /* we don't have stderr for interactive terminal sessions, see below */
+       if (fderr != -1)
+               set_nonblock(fderr);
+
        connection_in = packet_get_connection_in();
        connection_out = packet_get_connection_out();
 
@@ -436,7 +446,6 @@ server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
 
        /* Main loop of the server for the interactive session mode. */
        for (;;) {
-               fd_set readset, writeset;
 
                /* Process buffered packets from the client. */
                process_buffered_input_packets();
@@ -640,6 +649,7 @@ server_loop2(void)
                        while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
                                session_close_by_pid(pid, status);
                        child_terminated = 0;
+                       signal(SIGCHLD, sigchld_handler2);
                }
                channel_after_select(&readset, &writeset);
                process_input(&readset);
@@ -707,7 +717,16 @@ input_direct_tcpip(void)
        originator = packet_get_string(NULL);
        originator_port = packet_get_int();
        packet_done();
+
+       debug("open direct-tcpip: from %s port %d to %s port %d",
+          originator, originator_port, target, target_port);
+
        /* XXX check permission */
+       if (! no_port_forwarding_flag) {
+               xfree(target);
+               xfree(originator);
+               return -1;
+       }
        sock = channel_connect_to(target, target_port);
        xfree(target);
        xfree(originator);
@@ -733,7 +752,7 @@ server_input_channel_open(int type, int plen)
        rwindow = packet_get_int();
        rmaxpack = packet_get_int();
 
-       log("channel_input_open: ctype %s rchan %d win %d max %d",
+       debug("channel_input_open: ctype %s rchan %d win %d max %d",
            ctype, rchan, rwindow, rmaxpack);
 
        if (strcmp(ctype, "session") == 0) {
@@ -758,7 +777,6 @@ server_input_channel_open(int type, int plen)
                        channel_free(id);
                }
        } else if (strcmp(ctype, "direct-tcpip") == 0) {
-               debug("open direct-tcpip");
                id = input_direct_tcpip();
                if (id >= 0)
                        c = channel_lookup(id);
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