[hackers] [quark] Add esnprintf() and refactor some code || Laslo Hunhold

[git]

commit c8401c591fac7fd98349e05e595cdbe861998a90
Author:     Laslo Hunhold <d...@frign.de>
AuthorDate: Mon Mar 5 00:59:37 2018 +0100
Commit:     Laslo Hunhold <d...@frign.de>
CommitDate: Mon Mar 5 00:59:37 2018 +0100

    Add esnprintf() and refactor some code
    
    The (size_t) discards the case where the return value of snprintf is < 0. 
This
    is rather unlikely, but we'll keep it in mind anyway.

diff --git a/http.c b/http.c
index cf08ada..98dfb00 100644
--- a/http.c
+++ b/http.c
@@ -346,8 +346,8 @@ http_send_response(int fd, struct request *r)
 
                /* if we have a vhost prefix, prepend it to the target */
                if (s.vhost[i].prefix) {
-                       if ((size_t)snprintf(realtarget, sizeof(realtarget), 
"%s%s",
-                           s.vhost[i].prefix, realtarget) >= 
sizeof(realtarget)) {
+                       if (esnprintf(realtarget, sizeof(realtarget), "%s%s",
+                                     s.vhost[i].prefix, realtarget)) {
                                return http_send_status(fd, 
S_REQUEST_TOO_LARGE);
                        }
                }
@@ -363,8 +363,8 @@ http_send_response(int fd, struct request *r)
                        }
 
                        /* swap out target prefix */
-                       if ((size_t)snprintf(tmptarget, sizeof(tmptarget), 
"%s%s",
-                           s.map[i].to, realtarget + len) >= 
sizeof(tmptarget)) {
+                       if (esnprintf(tmptarget, sizeof(tmptarget), "%s%s",
+                                     s.map[i].to, realtarget + len)) {
                                return http_send_status(fd, 
S_REQUEST_TOO_LARGE);
                        }
                        memcpy(realtarget, tmptarget, sizeof(realtarget));
@@ -441,8 +441,8 @@ http_send_response(int fd, struct request *r)
 
        if (S_ISDIR(st.st_mode)) {
                /* append docindex to target */
-               if ((size_t)snprintf(realtarget, sizeof(realtarget), "%s%s",
-                   r->target, s.docindex) >= sizeof(realtarget)) {
+               if (esnprintf(realtarget, sizeof(realtarget), "%s%s",
+                             r->target, s.docindex)) {
                        return http_send_status(fd, S_REQUEST_TOO_LARGE);
                }
 
diff --git a/util.c b/util.c
index 1fe9db8..d3db040 100644
--- a/util.c
+++ b/util.c
@@ -61,6 +61,19 @@ timestamp(time_t t, char buf[TIMESTAMP_LEN])
        return buf;
 }
 
+int
+esnprintf(char *str, size_t size, const char *fmt, ...)
+{
+       va_list ap;
+       int ret;
+
+       va_start(ap, fmt);
+       ret = vsnprintf(str, size, fmt, ap);
+       va_end(ap);
+
+       return (ret < 0 || (size_t)ret >= size);
+}
+
 #define        INVALID  1
 #define        TOOSMALL 2
 #define        TOOLARGE 3
diff --git a/util.h b/util.h
index 1f9e107..8408ce3 100644
--- a/util.h
+++ b/util.h
@@ -49,6 +49,7 @@ void die(const char *, ...);
 #define TIMESTAMP_LEN 30
 
 char *timestamp(time_t, char buf[TIMESTAMP_LEN]);
+int esnprintf(char *, size_t, const char *, ...);
 
 void *reallocarray(void *, size_t, size_t);
 long long strtonum(const char *, long long, long long, const char **);