Restrict deep nesting of configfiles

There is no point in restricting the number of included config-
files, but there is a point in restricting the nestinglevel
of configfiles: to avoid recursive inclusions. This is easily
achieved by decrementing the static nesting-variable upon exit
from cgit_read_config().

Also fix some whitespace breakage.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/parsing.c b/parsing.c
index 8e15e5a..36b0f0c 100644
--- a/parsing.c
+++ b/parsing.c
@@ -9,239 +9,241 @@
 #include "cgit.h"
 
 int next_char(FILE *f)
 {
         int c = fgetc(f);
         if (c=='\r') {
                 c = fgetc(f);
                 if (c!='\n') {
                         ungetc(c, f);
                         c = '\r';
                 }
         }
         return c;
 }
 
 void skip_line(FILE *f)
 {
         int c;
 
         while((c=next_char(f)) && c!='\n' && c!=EOF)
                 ;
 }
 
 int read_config_line(FILE *f, char *line, const char **value, int bufsize)
 {
         int i = 0, isname = 0;
 
         *value = NULL;
         while(i<bufsize-1) {
                 int c = next_char(f);
                 if (!isname && (c=='#' || c==';')) {
                         skip_line(f);
                         continue;
                 }
                 if (!isname && isspace(c))
                         continue;
 
                 if (c=='=' && !*value) {
                         line[i] = 0;
                         *value = &line[i+1];
                 } else if (c=='\n' && !isname) {
                         i = 0;
                         continue;
                 } else if (c=='\n' || c==EOF) {
                         line[i] = 0;
                         break;
                 } else {
                         line[i]=c;
                 }
                 isname = 1;
                 i++;
         }
         line[i+1] = 0;
         return i;
 }
 
 int cgit_read_config(const char *filename, configfn fn)
 {
         static int nesting;
         int len;
         char line[256];
         const char *value;
         FILE *f;
 
-        /* cancel the reading of yet another configfile after 16 invocations */
-        if (nesting++ > 16)
+        /* cancel deeply nested include-commands */
+        if (nesting > 8)
                 return -1;
         if (!(f = fopen(filename, "r")))
                 return -1;
+        nesting++;
         while((len = read_config_line(f, line, &value, sizeof(line))) > 0)
                 (*fn)(line, value);
+        nesting--;
         fclose(f);
         return 0;
 }
 
 char *convert_query_hexchar(char *txt)
 {
         int d1, d2;
         if (strlen(txt) < 3) {
                 *txt = '\0';
                 return txt-1;
         }
         d1 = hextoint(*(txt+1));
         d2 = hextoint(*(txt+2));
         if (d1<0 || d2<0) {
                 strcpy(txt, txt+3);
                 return txt-1;
         } else {
                 *txt = d1 * 16 + d2;
                 strcpy(txt+1, txt+3);
                 return txt;
         }
 }
 
 int cgit_parse_query(char *txt, configfn fn)
 {
         char *t, *value = NULL, c;
 
         if (!txt)
                 return 0;
 
         t = txt = xstrdup(txt);
- 
+
         while((c=*t) != '\0') {
                 if (c=='=') {
                         *t = '\0';
                         value = t+1;
                 } else if (c=='+') {
                         *t = ' ';
                 } else if (c=='%') {
                         t = convert_query_hexchar(t);
                 } else if (c=='&') {
                         *t = '\0';
                         (*fn)(txt, value);
                         txt = t+1;
                         value = NULL;
                 }
                 t++;
         }
         if (t!=txt)
                 (*fn)(txt, value);
         return 0;
 }
 
 char *substr(const char *head, const char *tail)
 {
         char *buf;
 
         buf = xmalloc(tail - head + 1);
         strncpy(buf, head, tail - head);
         buf[tail - head] = '\0';
         return buf;
 }
 
 struct commitinfo *cgit_parse_commit(struct commit *commit)
 {
         struct commitinfo *ret;
         char *p = commit->buffer, *t = commit->buffer;
 
         ret = xmalloc(sizeof(*ret));
         ret->commit = commit;
         ret->author = NULL;
         ret->author_email = NULL;
         ret->committer = NULL;
         ret->committer_email = NULL;
         ret->subject = NULL;
         ret->msg = NULL;
 
         if (strncmp(p, "tree ", 5))
                 die("Bad commit: %s", sha1_to_hex(commit->object.sha1));
         else
                 p += 46; // "tree " + hex[40] + "\n"
 
         while (!strncmp(p, "parent ", 7))
                 p += 48; // "parent " + hex[40] + "\n"
 
         if (!strncmp(p, "author ", 7)) {
                 p += 7;
                 t = strchr(p, '<') - 1;
                 ret->author = substr(p, t);
                 p = t;
                 t = strchr(t, '>') + 1;
                 ret->author_email = substr(p, t);
                 ret->author_date = atol(++t);
                 p = strchr(t, '\n') + 1;
         }
 
         if (!strncmp(p, "committer ", 9)) {
                 p += 9;
                 t = strchr(p, '<') - 1;
                 ret->committer = substr(p, t);
                 p = t;
                 t = strchr(t, '>') + 1;
                 ret->committer_email = substr(p, t);
                 ret->committer_date = atol(++t);
                 p = strchr(t, '\n') + 1;
         }
 
         while (*p == '\n')
                 p = strchr(p, '\n') + 1;
 
         t = strchr(p, '\n');
         if (t && *t) {
                 ret->subject = substr(p, t);
                 p = t + 1;
 
                 while (*p == '\n')
                         p = strchr(p, '\n') + 1;
                 ret->msg = p;
         }
         return ret;
 }
 
 
 struct taginfo *cgit_parse_tag(struct tag *tag)
 {
         void *data;
         enum object_type type;
         unsigned long size;
         char *p, *t;
         struct taginfo *ret;
 
         data = read_sha1_file(tag->object.sha1, &type, &size);
         if (!data || type != OBJ_TAG) {
                 free(data);
                 return 0;
         }
-        
+
         ret = xmalloc(sizeof(*ret));
         ret->tagger = NULL;
         ret->tagger_email = NULL;
         ret->tagger_date = 0;
         ret->msg = NULL;
 
         p = data;
 
         while (p && *p) {
                 if (*p == '\n')
                         break;
 
                 if (!strncmp(p, "tagger ", 7)) {
                         p += 7;
                         t = strchr(p, '<') - 1;
                         ret->tagger = substr(p, t);
                         p = t;
                         t = strchr(t, '>') + 1;
                         ret->tagger_email = substr(p, t);
                         ret->tagger_date = atol(++t);
                 }
                 p = strchr(p, '\n') + 1;
         }
 
         while (p && (*p == '\n'))
                 p = strchr(p, '\n') + 1;
         if (p && *p)
                 ret->msg = xstrdup(p);
         free(data);
         return ret;
 }