X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/checkpath/blobdiff_plain/c7ade76f8e82fb51068cfd9e41b8268b35c50b13..972ca7cda65ce3fc9f150c20a56ad4836f3a7414:/checkpath.c?ds=sidebyside

diff --git a/checkpath.c b/checkpath.c
index 95524ae..2cb73cd 100644
--- a/checkpath.c
+++ b/checkpath.c
@@ -68,6 +68,8 @@ struct state {
   pool *p;				/* Allocation pool */
   struct elt *sp;			/* Stack pointer for list */
   dstr path;				/* Current path string */
+  dstr link;				/* Symbolic link target string */
+  dstr msg;				/* Message string */
 };
 
 /*----- Static variables --------------------------------------------------*/
@@ -78,7 +80,8 @@ static const struct elt rootnode = { 0, 0, 0 }; /* Root of the list */
 
 /* --- @splitpath@ --- *
  *
- * Arguments:	@const char *path@ = path string to break apart
+ * Arguments:	@struct state *state@ = pointer to state
+ *		@const char *path@ = path string to break apart
  *		@struct elt *tail@ = tail block to attach to end of list
  *
  * Returns:	Pointer to the new list head.
@@ -88,7 +91,8 @@ static const struct elt rootnode = { 0, 0, 0 }; /* Root of the list */
  *		be pushed onto the directory stack as required.
  */
 
-static struct elt *splitpath(const char *path, struct elt *tail)
+static struct elt *splitpath(struct state *state,
+			     const char *path, struct elt *tail)
 {
   struct elt *head, **ee = &head, *e;
   size_t n;
@@ -111,7 +115,7 @@ static struct elt *splitpath(const char *path, struct elt *tail)
      */
 
     n = strcspn(path, "/");
-    e = xmalloc(sizeof(struct elt) + n + 1);
+    e = pool_alloc(state->p, offsetof(struct elt, e_name) + n + 1);
     memcpy(e->e_name, path, n);
     e->e_name[n] = 0;
     e->e_flags = 0;
@@ -143,7 +147,7 @@ static void pop(struct state *state)
     e = sp->e_link;
     state->path.len = sp->e_offset;
     DPUTZ(&state->path);
-    xfree(state->sp); state->sp = e;
+    state->sp = e;
   }
 }
 
@@ -157,7 +161,7 @@ static void pop(struct state *state)
  */
 
 static void popall(struct state *state)
-  { while (state->sp->e_link) pop(state); }
+  { state->sp = (/*unconst*/ struct elt *)&rootnode; state->path.len = 0; }
 
 /* --- @push@ --- *
  *
@@ -180,7 +184,8 @@ static void push(struct state *state, struct elt *e)
 
 /* --- @report@ --- *
  *
- * Arguments:	@const struct checkpath *cp@ = pointer to query
+ * Arguments:	@struct state *state@ = pointer to state
+ *		@const struct checkpath *cp@ = pointer to query
  *		@unsigned what@ = what sort of report is this?
  *		@int verbose@ = how verbose is this?
  *		@const char *p@ = what path does it refer to?
@@ -191,10 +196,10 @@ static void push(struct state *state, struct elt *e)
  * Use:		Formats and presents messages to the client.
  */
 
-static void report(const struct checkpath *cp, unsigned what, int verbose,
+static void report(struct state *state, const struct checkpath *cp,
+		   unsigned what, int verbose,
 		   const char *p, const char *msg, ...)
 {
-  dstr d = DSTR_INIT;
   va_list ap;
   const char *q = msg;
   const char *s;
@@ -219,56 +224,56 @@ static void report(const struct checkpath *cp, unsigned what, int verbose,
 
   /* --- Format the message nicely --- */
 
+  dstr_reset(&state->msg);
   va_start(ap, msg);
   if (verbose > 1)
-    dstr_puts(&d, "[ ");
+    dstr_puts(&state->msg, "[ ");
   if (p)
-    dstr_putf(&d, "Path: %s: ", p);
+    dstr_putf(&state->msg, "Path: %s: ", p);
   while (*q) {
     if (*q == '%') {
       q++;
       switch (*q) {
 	case 'e':
-	  dstr_puts(&d, strerror(e));
+	  dstr_puts(&state->msg, strerror(e));
 	  break;
 	case 'u':
-	  u = (uid_t)va_arg(ap, int);
+	  u = (uid_t)va_arg(ap, long);
 	  if ((pw = getpwuid(u)) != 0)
-	    dstr_putf(&d, "`%s'", pw->pw_name);
+	    dstr_putf(&state->msg, "`%s'", pw->pw_name);
 	  else
-	    dstr_putf(&d, "%i", (int)u);
+	    dstr_putf(&state->msg, "#%ld", (long)u);
 	  break;
 	case 'g':
-	  g = (gid_t)va_arg(ap, int);
+	  g = (gid_t)va_arg(ap, long);
 	  if ((gr = getgrgid(g)) != 0)
-	    dstr_putf(&d, "`%s'", gr->gr_name);
+	    dstr_putf(&state->msg, "`%s'", gr->gr_name);
 	  else
-	    dstr_putf(&d, "%i", (int)g);
+	    dstr_putf(&state->msg, "#%ld", (long)g);
 	  break;
 	case 's':
 	  s = va_arg(ap, const char *);
-	  dstr_puts(&d, s);
+	  dstr_puts(&state->msg, s);
 	  break;
 	case '%':
-	  dstr_putc(&d, '%');
+	  dstr_putc(&state->msg, '%');
 	  break;
 	default:
-	  dstr_putc(&d, '%');
-	  dstr_putc(&d, *q);
+	  dstr_putc(&state->msg, '%');
+	  dstr_putc(&state->msg, *q);
 	  break;
       }
       q++;
     } else {
       n = strcspn(q, "%");
-      DPUTM(&d, q, n);
+      DPUTM(&state->msg, q, n);
       q += n;
     }
   }
   if (verbose > 1)
-    dstr_puts(&d, " ]");
-  DPUTZ(&d);
-  cp->cp_report(what, verbose, p, d.buf, cp->cp_arg);
-  dstr_destroy(&d);
+    dstr_puts(&state->msg, " ]");
+  DPUTZ(&state->msg);
+  cp->cp_report(what, verbose, p, state->msg.buf, cp->cp_arg);
   va_end(ap);
 }
 
@@ -276,6 +281,7 @@ static void report(const struct checkpath *cp, unsigned what, int verbose,
  *
  * Arguments:	@const char *p@ = name of directory to check
  *		@struct stat *st@ = pointer to @stat@(2) block for it
+ *		@struct state *state@ = pointer to state
  *		@const struct checkpath *cp@ = pointer to query
  *		@unsigned f@ = various flags (@SF_...@)
  *
@@ -289,7 +295,8 @@ static void report(const struct checkpath *cp, unsigned what, int verbose,
 #define SF_LAST 1u			/* This is the final item to check */
 
 static unsigned sanity(const char *p, struct stat *st,
-		       const struct checkpath *cp, unsigned f)
+		       struct state *state, const struct checkpath *cp,
+		       unsigned f)
 {
   unsigned bad = 0;
   int stickyok = 0;
@@ -305,7 +312,7 @@ static unsigned sanity(const char *p, struct stat *st,
   if ((cp->cp_what & CP_WRWORLD) &&
       (st->st_mode & (S_IWOTH | stickyok)) == S_IWOTH) {
     bad |= CP_WRWORLD;
-    report(cp, CP_WRWORLD, 1, p, "** world writable **");
+    report(state, cp, CP_WRWORLD, 1, p, "** world writable **");
   }
 
   /* --- Check for group-writability --- */
@@ -323,8 +330,8 @@ static unsigned sanity(const char *p, struct stat *st,
     }
     if (b) {
       bad |= b;
-      report(cp, b, 1, p, "writable by %sgroup %g",
-	     (b == CP_WROTHGRP) ? "other " : "", st->st_gid);
+      report(state, cp, b, 1, p, "writable by %sgroup %g",
+	     (b == CP_WROTHGRP) ? "other " : "", (long)st->st_gid);
     }
   }
 
@@ -334,7 +341,8 @@ static unsigned sanity(const char *p, struct stat *st,
       st->st_uid != cp->cp_uid &&
       st->st_uid != 0) {
     bad |= CP_WROTHUSR;
-    report(cp, CP_WROTHUSR, 1, p, "owner is user %u", st->st_uid);
+    report(state, cp, CP_WROTHUSR, 1, p,
+	   "owner is user %u", (long)st->st_uid);
   }
 
   /* --- Done sanity check --- */
@@ -361,7 +369,6 @@ unsigned checkpath(const char *p, const struct checkpath *cp)
   pool *pp;
   struct stat st;
   unsigned bad = 0;
-  dstr buf = DSTR_INIT;
   int i;
 
   /* --- Initialize the state --- */
@@ -371,29 +378,31 @@ unsigned checkpath(const char *p, const struct checkpath *cp)
   state->p = pp;
   state->sp = (/*unconst*/ struct elt *)&rootnode;
   dstr_create(&state->path);
+  dstr_create(&state->link);
+  dstr_create(&state->msg);
 
   /* --- Try to find the current directory --- */
 
   if (!getcwd(cwd, sizeof(cwd))) {
-    report(cp, CP_ERROR, 0, 0, "can't find current directory: %e");
+    report(state, cp, CP_ERROR, 0, 0, "can't find current directory: %e");
     return (CP_ERROR);
   }
 
   /* --- Check that the root directory is OK --- */
 
   if (stat("/", &st)) {
-    report(cp, CP_ERROR, 0, 0, "can't stat root directory: %e");
+    report(state, cp, CP_ERROR, 0, 0, "can't stat root directory: %e");
     return (CP_ERROR);
   }
 
-  report(cp, CP_REPORT, 3, p, "begin scan");
-  bad |= sanity("/", &st, cp, 0);
+  report(state, cp, CP_REPORT, 3, p, "begin scan");
+  bad |= sanity("/", &st, state, cp, 0);
 
   /* --- Get the initial list of things to process --- */
 
-  ee = splitpath(p, 0);
+  ee = splitpath(state, p, 0);
   if (*p != '/')
-    ee = splitpath(cwd, ee);
+    ee = splitpath(state, cwd, ee);
 
   /* --- While there are list items which still need doing --- */
 
@@ -403,7 +412,6 @@ unsigned checkpath(const char *p, const struct checkpath *cp)
     /* --- Strip off simple `.' elements --- */
 
     if (strcmp(ee->e_name, ".") == 0) {
-      xfree(ee);
       ee = e;
       continue;
     }
@@ -412,7 +420,6 @@ unsigned checkpath(const char *p, const struct checkpath *cp)
 
     else if (strcmp(ee->e_name, "..") == 0) {
       pop(state);
-      xfree(ee);
       ee = e;
       continue;
     }
@@ -425,7 +432,7 @@ unsigned checkpath(const char *p, const struct checkpath *cp)
     /* --- Find out what sort of a thing this is --- */
 
     if (lstat(state->path.buf, &st)) {
-      report(cp, CP_ERROR, 0, state->path.buf, "can't stat: %e");
+      report(state, cp, CP_ERROR, 0, state->path.buf, "can't stat: %e");
       bad |= CP_ERROR;
       break;
     }
@@ -436,15 +443,18 @@ unsigned checkpath(const char *p, const struct checkpath *cp)
 
       /* --- Resolve the link --- */
 
-      dstr_reset(&buf);
-      dstr_ensure(&buf, st.st_size + 1);
-      if ((i = readlink(state->path.buf, buf.buf, buf.sz)) < 0) {
-	report(cp, CP_ERROR, 0, state->path.buf, "can't readlink: %e");
+      dstr_reset(&state->link);
+      dstr_ensure(&state->link, st.st_size + 1);
+      if ((i = readlink(state->path.buf,
+			state->link.buf, state->link.sz)) < 0) {
+	report(state, cp, CP_ERROR, 0, state->path.buf,
+	       "can't readlink: %e");
 	bad |= CP_ERROR;
 	break;
       }
-      buf.buf[i] = 0;
-      report(cp, CP_SYMLINK, 2, state->path.buf, "symlink -> `%s'", buf.buf);
+      state->link.buf[i] = 0;
+      report(state, cp, CP_SYMLINK, 2, state->path.buf,
+	     "symlink -> `%s'", state->link.buf);
 
       /* --- Handle sticky parents --- *
        *
@@ -457,28 +467,28 @@ unsigned checkpath(const char *p, const struct checkpath *cp)
 	  (state->sp->e_link->e_flags & EF_STICKY) &&
 	  st.st_uid != cp->cp_uid && st.st_uid != 0) {
 	bad |= CP_WROTHUSR;
-	report(cp, CP_WROTHUSR, 1, state->path.buf,
-	       "symlink modifiable by user %u", st.st_uid);
+	report(state, cp, CP_WROTHUSR, 1, state->path.buf,
+	       "symlink modifiable by user %u", (long)st.st_uid);
       }
 
       /* --- Sort out what to do from here --- */
 
-      if (buf.buf[0] == '/')
+      if (state->link.buf[0] == '/')
 	popall(state);
       else
 	pop(state);
-      ee = splitpath(buf.buf, ee);
+      ee = splitpath(state, state->link.buf, ee);
       continue;
     }
 
     /* --- Run the sanity check on this path element --- */
 
-    bad |= sanity(state->path.buf, &st, cp, ee ? 0 : SF_LAST);
+    bad |= sanity(state->path.buf, &st, state, cp, ee ? 0 : SF_LAST);
 
     if (S_ISDIR(st.st_mode)) {
       if (st.st_mode & S_ISVTX)
 	state->sp->e_flags |= EF_STICKY;
-      report(cp, CP_REPORT, 4, state->path.buf, "directory");
+      report(state, cp, CP_REPORT, 4, state->path.buf, "directory");
       continue;
     }
 
@@ -491,17 +501,16 @@ unsigned checkpath(const char *p, const struct checkpath *cp)
 
   if (ee) {
     if (!(bad & CP_ERROR))
-      report(cp, CP_ERROR, 0, 0, "junk left over after reaching leaf");
+      report(state, cp, CP_ERROR, 0, 0, "junk left over after reaching leaf");
     while (ee) {
       e = ee->e_link;
-      xfree(ee);
       ee = e;
     }
   }
 
-  popall(state);
   dstr_destroy(&state->path);
-  dstr_destroy(&buf);
+  dstr_destroy(&state->link);
+  dstr_destroy(&state->msg);
   pool_destroy(state->p);
   return (bad);
 }