[MEDIUM] Handle long lines properly

Currently, there is a hidden line length limit in the haproxy, set
to 256-1 chars. With large acls (for example many hdr(host) matches)
it may be not enough and which is even worse, error message may
be totally confusing as everything above this limit is treated
as a next line:

echo -ne "frontend aqq 1.2.3.4:80\nmode http\nacl e hdr(host) -i X X X X X X X www.xx.example.com stats\n"|
 sed s/X/www.some-host-name.example.com/g > ha.cfg && haproxy -c -f ./ha.cfg

[WARNING] 300/163906 (11342) : parsing [./ha.cfg:4] : 'stats' ignored because frontend 'aqq' has no backend capability.

Recently I hit simmilar problem and it took me a while to find why
requests for "stats" are not handled properly.

This patch:
 - makes the limit configurable (LINESIZE)
 - increases default line length limit from 256 to 2048
 - increases MAX_LINE_ARGS from 40 to 64
 - fixes hidden assignment in fgets()
 - moves arg/end/args/line inside the loop, making code auditing easier
 - adds a check that shows error if the limit is reached
 - changes "*line++ = 0;" to "*line++ = '\0';" (cosmetics)

With this patch, when LINESIZE is defined to 256, above example produces:
[ALERT] 300/164724 (27364) : parsing [/tmp/ha.cfg:3]: line too long, limit: 255.
[ALERT] 300/164724 (27364) : Error reading configuration file : /tmp/ha.cfg

diff --git a/include/common/defaults.h b/include/common/defaults.h
index 2c757d2f585174690c156a573e0741054216057f..2be753d0e46e9e8d7e2547ab1a1b5524bf767653 100644 (file)
--- a/include/common/defaults.h
+++ b/include/common/defaults.h
@@ -43,8 +43,13 @@
 #define REQURI_LEN      1024
 #define CAPTURE_LEN     64
 
+// maximum line size when parsing config
+#ifndef LINESIZE
+#define LINESIZE       2048
+#endif
+
 // max # args on a configuration line
-#define MAX_LINE_ARGS   40
+#define MAX_LINE_ARGS   64
 
 // max # of added headers per request
 #define MAX_NEWHDR      10

diff --git a/src/cfgparse.c b/src/cfgparse.c
index 4cb71113e975aa3362ee0346a9e85777ad68cde5..8313a3544465818d33a58f7af2b8747a76cbd23f 100644 (file)
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -2268,13 +2268,9 @@ int cfg_parse_listen(const char *file, int linenum, char **args)
  */
 int readcfgfile(const char *file)
 {
-       char thisline[256];
-       char *line;
+       char thisline[LINESIZE];
        FILE *f;
        int linenum = 0;
-       char *end;
-       char *args[MAX_LINE_ARGS + 1];
-       int arg;
        int cfgerr = 0;
        int confsect = CFG_NONE;
 
@@ -2286,11 +2282,25 @@ int readcfgfile(const char *file)
 
        init_default_instance();
 
-       while (fgets(line = thisline, sizeof(thisline), f) != NULL) {
+       while (fgets(thisline, sizeof(thisline), f) != NULL) {
+               int arg;
+               char *end;
+               char *args[MAX_LINE_ARGS + 1];
+               char *line = thisline;
+
                linenum++;
 
                end = line + strlen(line);
 
+               if (end-line == sizeof(thisline)-1 && *(end-1) != '\n') {
+                       /* Check if we reached the limit and the last char is not \n.
+                        * Watch out for the last line without the terminating '\n'!
+                        */
+                       Alert("parsing [%s:%d]: line too long, limit: %d.\n",
+                               file, linenum, sizeof(thisline)-1);
+                       return -1;
+               }
+
                /* skip leading spaces */
                while (isspace((unsigned char)*line))
                        line++;
@@ -2348,7 +2358,7 @@ int readcfgfile(const char *file)
                        }
                        else if (isspace((unsigned char)*line)) {
                                /* a non-escaped space is an argument separator */
-                               *line++ = 0;
+                               *line++ = '\0';
                                while (isspace((unsigned char)*line))
                                        line++;
                                args[++arg] = line;