Ensure log filenames are safe for writing.

1 files changed, 27 insertions, 4 deletions

diff --git a/logging.c b/logging.c
index 5b790b1..6e8d9b7 100644
--- a/logging.c
+++ b/logging.c
@@ -77,10 +77,24 @@ int logline(char *str, char *ournick, char *basedir, int type) {
     debugprint(DEBUG_FULL, "logline(): extracted '%s'.\n", tokens[i]);
   }
 
+  // Make "filename safe" copies of from and to names to ensure filename ends up being safe
+  char from[MAXCHAR], to[MAXCHAR];
+  strcpy(from, tokens[0]);
+  strcpy(to, tokens[2]);
+  // Remove unsafe characters (assuming POSIX, just strip "/" and replace with "_")
+  replacechar(from, '/', '_');
+  replacechar(to, '/', '_');
+  // Ensure filename wouldn't be too long
+  if (strlen(from) > NAME_MAX || strlen(to) > NAME_MAX) {
+    debugprint(DEBUG_CRIT, "Filename would be too long if logging either '%s' or '%s', returning!\n", from, to);
+    return 0;
+  }
+
   switch(type) {
     case LOG_PRIVMSG:
       // Extract the username from the prefix
       extractnickfromprefix(tokens[0]);
+      extractnickfromprefix(from);
 
       // Remove the leading ":" from the real message
       stripprefix(str);
@@ -88,10 +102,16 @@ int logline(char *str, char *ournick, char *basedir, int type) {
       // Build the log filename
       // If the message was sent to us, then log it in the sender's log file
       if (strncmp(tokens[2], ournick, strlen(tokens[0])) == 0) {
-        snprintf(filename, MAXCHAR, "%s/logs/%s.log", basedir, tokens[0]);
+        if (!snprintf(filename, MAXCHAR, "%s/logs/%s.log", basedir, from)) {
+          debugprint(DEBUG_CRIT, "Error while log filename for from name, returning!\n");
+          return 0;
+        }
       } else {
         // Otherwise log it in the "to" log file
-        snprintf(filename, MAXCHAR, "%s/logs/%s.log", basedir, tokens[2]);
+        if (!snprintf(filename, MAXCHAR, "%s/logs/%s.log", basedir, to)) {
+          debugprint(DEBUG_CRIT, "Error while log filename for to name, returning!\n");
+          return 0;
+        }
       }
 
       debugprint(DEBUG_FULL, "logline(): Logging PRIVMSG from '%s' to '%s' message '%s' in filename '%s'.\n", tokens[0], tokens[2], str, filename);
@@ -112,7 +132,7 @@ int logline(char *str, char *ournick, char *basedir, int type) {
         return 0;
       }
 
-      snprintf(filename, MAXCHAR, "%s/logs/%s.log", basedir, tokens[2] + pos);
+      snprintf(filename, MAXCHAR, "%s/logs/%s.log", basedir, to + pos);
 
       debugprint(DEBUG_FULL, "logline(): Logging JOIN/PART to/from '%s' in filename '%s'.\n", tokens[2] + pos, filename);
 
@@ -151,7 +171,10 @@ int logline(char *str, char *ournick, char *basedir, int type) {
       // Remove the leading ":" from the topic
       stripprefix(str);
 
-      snprintf(filename, MAXCHAR, "%s/logs/%s.log", basedir, tokens[2]);
+      if (!snprintf(filename, MAXCHAR, "%s/logs/%s.log", basedir, to)) {
+        debugprint(DEBUG_CRIT, "Error while log filename for topic, returning!\n");
+        return 0;
+      }
 
       debugprint(DEBUG_FULL, "logline(): Logging TOPIC for '%s' in filename '%s'.\n", tokens[2], filename);