Allow a path to be specified for the chansrv log

This is useful for NFS-mounted home directories, where hosts
may otherwise produce colliding chansrv log file names

(cherry picked from commit cfc2e362b47103bc2c786252f331bb26b6ddecb5)

docs/man/sesman.ini.5.in

@@ -409,6 +409,28 @@ Sets the duration(msec). Sound data is not send to client during \fInumber\fR
 millisecond(s) after close message is sent, when AAC/MP3 is selected.
 If set to 0, all the data is sent. If not specified, defaults to \fI1000\fR.
 
+.TP
+\fBLogFilePath\fR=\fIstring\fR
+Directory for storing the chansrv log file
+Created if it doesn't exist.
+If first character is not a '/', this is relative to $HOME.
+.P
+.RS
+The following substitutions are made in this string:-
+    %U - Username
+    %u - Numeric UID
+    %% - Percent character
+.P
+This is most useful if you are using NFS-mounted home directories, and
+wish to move the chansrv log file to the local disk.
+
+If this isn't specified, the log file is stored in one of the following
+locations :-
+    -   $CHANSRV_LOG_PATH
+    -   $XDG_DATA_HOME/xrdp
+    -   $HOME/.local/share/xrdp
+.RE
+
 .SH "SESSIONS VARIABLES"
 All entries in the \fB[SessionVariables]\fR section are set as
 environment variables in the user's session.

sesman/chansrv/chansrv.c

@@ -1694,20 +1694,32 @@ get_log_path(char *path, int bytes)
     int rv;
 
     rv = 1;
-    log_path = g_getenv("CHANSRV_LOG_PATH");
-    if (log_path == 0)
+    if (g_cfg->log_file_path != NULL && g_cfg->log_file_path[0] != '\0')
     {
-        log_path = g_getenv("XDG_DATA_HOME");
-        if (log_path != 0)
+        char uidstr[64];
+        char username[64];
+        const struct info_string_tag map[] =
         {
-            g_snprintf(path, bytes, "%s%s", log_path, "/xrdp");
-            if (g_directory_exist(path) || (g_mkdir(path) == 0))
-            {
-                rv = 0;
-            }
+            {'u', uidstr},
+            {'U', username},
+            INFO_STRING_END_OF_LIST
+        };
+
+        int uid = g_getuid();
+        g_snprintf(uidstr, sizeof(uidstr), "%d", uid);
+        if (g_getlogin(username, sizeof(username)) != 0)
+        {
+            /* Fall back to UID */
+            g_strncpy(username, uidstr, sizeof(username) - 1);
+        }
+
+        (void)g_format_info_string(path, bytes, g_cfg->log_file_path, map);
+        if (g_directory_exist(path) || (g_mkdir(path) == 0))
+        {
+            rv = 0;
         }
     }
-    else
+    else if ((log_path = g_getenv("CHANSRV_LOG_PATH")) != 0)
     {
         g_snprintf(path, bytes, "%s", log_path);
         if (g_directory_exist(path) || (g_mkdir(path) == 0))
@@ -1715,6 +1727,16 @@ get_log_path(char *path, int bytes)
             rv = 0;
         }
     }
+    else if ((log_path = g_getenv("XDG_DATA_HOME")) != 0)
+    {
+        g_snprintf(path, bytes, "%s%s", log_path, "/xrdp");
+        if (g_directory_exist(path) || (g_mkdir(path) == 0))
+        {
+            rv = 0;
+        }
+    }
+
+    // Always fall back to the home directory
     if (rv != 0)
     {
         log_path = g_getenv("HOME");
@@ -1830,14 +1852,6 @@ main(int argc, char **argv)
     g_init("xrdp-chansrv"); /* os_calls */
     g_memset(g_drdynvcs, 0, sizeof(g_drdynvcs));
 
-    log_path[255] = 0;
-    if (get_log_path(log_path, 255) != 0)
-    {
-        g_writeln("error reading CHANSRV_LOG_PATH and HOME environment variable");
-        main_cleanup();
-        return 1;
-    }
-
     display_text = g_getenv("DISPLAY");
     if (display_text == NULL)
     {
@@ -1864,6 +1878,13 @@ main(int argc, char **argv)
     }
     config_dump(g_cfg);
 
+    if (get_log_path(log_path, sizeof(log_path)) != 0)
+    {
+        g_writeln("error reading CHANSRV_LOG_PATH and HOME environment variable");
+        main_cleanup();
+        return 1;
+    }
+
     pid = g_getpid();
 
     /* starting logging subsystem */

sesman/chansrv/chansrv_config.c

@@ -46,6 +46,7 @@
 #define DEFAULT_NUM_SILENT_FRAMES_AAC       4
 #define DEFAULT_NUM_SILENT_FRAMES_MP3       2
 #define DEFAULT_MSEC_DO_NOT_SEND            1000
+#define DEFAULT_LOG_FILE_PATH               ""
 /**
  * Type used for passing a logging function about
  */
@@ -243,6 +244,17 @@ read_config_chansrv(log_func_t logmsg,
         {
             cfg->msec_do_not_send = strtoul(value, NULL, 0);
         }
+        else if (g_strcasecmp(name, "LogFilePath") == 0)
+        {
+            g_free(cfg->log_file_path);
+            cfg->log_file_path = g_strdup(value);
+            if (cfg->log_file_path == NULL)
+            {
+                logmsg(LOG_LEVEL_ERROR, "Can't alloc LogFilePath");
+                error = 1;
+                break;
+            }
+        }
     }
 
     return error;
@@ -259,9 +271,11 @@ new_config(void)
     /* Do all the allocations at the beginning, then check them together */
     struct config_chansrv *cfg = g_new0(struct config_chansrv, 1);
     char *fuse_mount_name = g_strdup(DEFAULT_FUSE_MOUNT_NAME);
-    if (cfg == NULL || fuse_mount_name == NULL)
+    char *log_file_path = g_strdup(DEFAULT_LOG_FILE_PATH);
+    if (cfg == NULL || fuse_mount_name == NULL || log_file_path == NULL)
     {
         /* At least one memory allocation failed */
+        g_free(log_file_path);
         g_free(fuse_mount_name);
         g_free(cfg);
         cfg = NULL;
@@ -279,6 +293,7 @@ new_config(void)
         cfg->num_silent_frames_aac = DEFAULT_NUM_SILENT_FRAMES_AAC;
         cfg->num_silent_frames_mp3 = DEFAULT_NUM_SILENT_FRAMES_MP3;
         cfg->msec_do_not_send = DEFAULT_MSEC_DO_NOT_SEND;
+        cfg->log_file_path = log_file_path;
     }
 
     return cfg;
@@ -375,6 +390,8 @@ config_dump(struct config_chansrv *config)
     g_writeln("    FileMask:                  0%o", config->file_umask);
     g_writeln("    Nautilus 3 Flist Format:   %s",
               g_bool2text(config->use_nautilus3_flist_format));
+    g_writeln("    LogFilePath            :   %s",
+              (config->log_file_path) ? config->log_file_path : "<default>");
 }
 
 /******************************************************************************/
@@ -385,6 +402,7 @@ config_free(struct config_chansrv *cc)
     {
         g_free(cc->listen_port);
         g_free(cc->fuse_mount_name);
+        g_free(cc->log_file_path);
         g_free(cc);
     }
 }

sesman/chansrv/chansrv_config.h

@@ -50,6 +50,9 @@ struct config_chansrv
     unsigned int num_silent_frames_mp3;
     /** Do net send sound data afer SNDC_CLOSE is sent. unit is millisecond, setting from sesman.ini */
     unsigned int msec_do_not_send;
+
+    /** LogFilePath from sesman.ini */
+    char *log_file_path;
 };
 
 

sesman/sesman.ini.in

@@ -191,6 +191,11 @@ FileUmask=077
 #SoundNumSilentFramesAAC=4
 #SoundNumSilentFramesMP3=2
 #SoundMsecDoNotSend=1000
+; Log file path
+; Set this to move the log file away from its default location. You may want
+; to do this for (e.g.) NFS-mounted home directories
+; See sesman.ini(5) for the format of this parameter
+#LogFilePath=/run/user/%u/xrdp
 
 [ChansrvLogging]
 ; Note: one log file is created per display and the LogFile config value