commit e3df66af907f6f14b2bd9176285701fa94bac81a
parent 921eb9b5db37cb6e8d463b9a0aee085c8c453c50
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Sun, 4 Jan 2015 18:54:06 +0100
snprintf() truncation checks
Diffstat:
2 files changed, 29 insertions(+), 17 deletions(-)
diff --git a/sfeed.c b/sfeed.c
@@ -360,8 +360,8 @@ parsetime(const char *s, char *buf, size_t bufsiz, time_t *tp)
NULL
};
char *p;
- unsigned int i;
- int tzoffset;
+ size_t i;
+ int tzoffset, r;
memset(&tm, 0, sizeof(tm));
for(i = 0; formats[i]; i++) {
@@ -372,11 +372,14 @@ parsetime(const char *s, char *buf, size_t bufsiz, time_t *tp)
return -1;
if(gettimetz(p, tz, sizeof(tz), &tzoffset) != -1)
t -= tzoffset;
- if(buf)
- snprintf(buf, bufsiz,
+ if(buf) {
+ r = snprintf(buf, bufsiz,
"%04d-%02d-%02d %02d:%02d:%02d %s",
tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec, tz);
+ if(r == -1 || (size_t)r >= bufsiz)
+ return -1; /* truncation */
+ }
if(tp)
*tp = t;
return 0;
diff --git a/sfeed_frames.c b/sfeed_frames.c
@@ -52,6 +52,22 @@ xerr(int eval, const char *fmt, ...)
va_end(ap);
}
+static int
+esnprintf(char *str, size_t size, const char *fmt, ...)
+{
+ va_list ap;
+ int r;
+
+ va_start(ap, fmt);
+ r = vsnprintf(str, size, fmt, ap);
+ va_end(ap);
+
+ if(r == -1 || (size_t)r >= size)
+ xerr(1, "snprintf");
+
+ return r;
+}
+
/* print text, ignore tabs, newline and carriage return etc
* print some HTML 2.0 / XML 1.0 as normal text */
static void
@@ -125,18 +141,14 @@ main(int argc, char *argv[])
basepathlen = strlen(basepath);
if(basepathlen > 0)
mkdir(basepath, S_IRWXU);
-
/* write main index page */
- if(snprintf(dirpath, sizeof(dirpath), "%s/index.html", basepath) <= 0)
- xerr(1, "snprintf");
+ esnprintf(dirpath, sizeof(dirpath), "%s/index.html", basepath);
if(!(fpindex = fopen(dirpath, "w+b")))
xerr(1, "fopen");
- if(snprintf(dirpath, sizeof(dirpath), "%s/menu.html", basepath) <= 0)
- xerr(1, "snprintf");
+ esnprintf(dirpath, sizeof(dirpath), "%s/menu.html", basepath);
if(!(fpmenu = fopen(dirpath, "w+b")))
xerr(1, "fopen: can't write menu.html");
- if(snprintf(dirpath, sizeof(dirpath), "%s/items.html", basepath) <= 0)
- xerr(1, "snprintf");
+ esnprintf(dirpath, sizeof(dirpath), "%s/items.html", basepath);
if(!(fpitems = fopen(dirpath, "w+b")))
xerr(1, "fopen");
fputs("<html><head><link rel=\"stylesheet\" type=\"text/css\" href=\"../style.css\" />"
@@ -160,8 +172,7 @@ main(int argc, char *argv[])
if(!(namelen = makepathname(feedname, name, sizeof(name))))
continue;
- if(snprintf(dirpath, sizeof(dirpath), "%s/%s", basepath, name) <= 0)
- xerr(1, "snprintf");
+ esnprintf(dirpath, sizeof(dirpath), "%s/%s", basepath, name);
/* directory doesn't exist: try to create it. */
if(stat(dirpath, &st) == -1 && mkdir(dirpath, S_IRWXU) == -1)
@@ -198,10 +209,8 @@ main(int argc, char *argv[])
/* write content */
if(!(namelen = makepathname(fields[FieldTitle], name, sizeof(name))))
continue;
- if(snprintf(filepath, sizeof(filepath), "%s/%s.html", dirpath, name) <= 0)
- xerr(1, "snprintf");
- if(snprintf(relfilepath, sizeof(relfilepath), "%s/%s.html", reldirpath, name) <= 0)
- xerr(1, "snprintf");
+ esnprintf(filepath, sizeof(filepath), "%s/%s.html", dirpath, name);
+ esnprintf(relfilepath, sizeof(relfilepath), "%s/%s.html", reldirpath, name);
/* file doesn't exist yet and has write access */
if(access(filepath, F_OK) != 0 && (fpcontent = fopen(filepath, "w+b"))) {
