make a stab at detecting fs layout

packages/00common/src/claim.cgi.c

@@ -11,6 +11,7 @@ main(int argc, char *argv[])
   if (-1 == cgi_init(argv)) {
     return 0;
   }
+  ctf_chdir();
 
   /* Read in team and token */
   while (1) {

packages/00common/src/common.c

@@ -363,6 +363,33 @@ my_snprintf(char *buf, size_t buflen, char *fmt, ...)
   }
 }
 
+
+void
+ctf_chdir()
+{
+    char const *ctf_base = getenv("CTF_BASE");
+    int i;
+
+    if (ctf_base) {
+        /* chdir to CTF_BASE */
+        chdir(ctf_base);
+    }
+
+    /* Keep going up one directory until there's a packages directory */
+    for (i = 0; i < 5; i += 1) {
+        struct stat st;
+
+        if ((0 == stat("packages", &st)) &&
+               S_ISDIR(st.st_mode)) {
+            return;
+        }
+        chdir("..");
+    }
+    fprintf(stderr, "Can not determine CTF_BASE directory: exiting.\n");
+    exit(66);
+}
+
+
 static char *
 mkpath(char const *type, char const *fmt, va_list ap)
 {

packages/00common/src/common.h

@@ -23,6 +23,7 @@ void cgi_page(char *title, char *fmt, ...);
 void cgi_error(char *text);
 
 
+void ctf_chdir();
 int anchored_search(char const *filename, char const *needle, const char anchor);
 void urandom(char *buf, size_t buflen);
 int my_snprintf(char *buf, size_t buflen, char *fmt, ...);

packages/00common/src/pointscli.c

@@ -16,6 +16,7 @@ main(int argc, char *argv[])
                 "Usage: pointscli TEAM CATEGORY POINTS 'COMMENT'\n");
         return EX_USAGE;
     }
+    ctf_chdir();
 
     points = atoi(argv[3]);
     if (0 == points) {

packages/00common/src/puzzler.cgi.c

@@ -15,6 +15,7 @@ main(int argc, char *argv[])
   if (-1 == cgi_init(argv)) {
     return 0;
   }
+  ctf_chdir();
 
   /* Read in team and answer */
   while (1) {

packages/00common/src/puzzles.cgi.c

@@ -57,6 +57,7 @@ main(int argc, char *argv[])
   if (-1 == cgi_init(argv)) {
     return 0;
   }
+  ctf_chdir();
 
   {
     FILE *f = fopen(state_path("points.log"), "r");