Linux: Improve privsep code a little

diff --git a/src/privsep-linux.c b/src/privsep-linux.c
index 509b86d63824280e3b206372ff9cb89ca59475fa..0bcd927535ddc3eb679cf1a75df3acf834e8a7fd 100644 (file)
--- a/src/privsep-linux.c
+++ b/src/privsep-linux.c
@@ -29,6 +29,7 @@
 #include <sys/ioctl.h>
 
 #include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
@@ -61,10 +62,10 @@ static ssize_t
 ps_root_dowritepathuint(const void *data, size_t len)
 {
        const char *path = data;
-       FILE *fp;
-       ssize_t r;
        size_t plen;
        unsigned int val;
+       int fd;
+       ssize_t r;
 
        if (len < sizeof(plen)) {
                errno = EINVAL;
@@ -80,11 +81,12 @@ ps_root_dowritepathuint(const void *data, size_t len)
 
        memcpy(&val, path + plen, sizeof(val));
 
-       fp = fopen(path, "w");
-       if (fp == NULL)
+       fd = open(path, O_WRONLY);
+       if (fd == -1)
                return -1;
-       r = fprintf(fp, "%u\n", val);
-       fclose(fp);
+       r = dprintf(fd, "%u", val);
+       close(fd);
+
        return r;
 }
 
@@ -120,7 +122,7 @@ ssize_t
 ps_root_writepathuint(struct dhcpcd_ctx *ctx, const char *path,
     unsigned int val)
 {
-       char buf[PS_BUFLEN];
+       char buf[PS_BUFLEN], *p = buf;
        size_t plen = strlen(path) + 1;
        size_t len = sizeof(plen) + plen + sizeof(val);
 
@@ -129,9 +131,11 @@ ps_root_writepathuint(struct dhcpcd_ctx *ctx, const char *path,
                return -1;
        }
 
-       memcpy(buf, &plen, sizeof(plen));
-       memcpy(buf + sizeof(plen), path, plen);
-       memcpy(buf + sizeof(plen) + plen, &val, sizeof(val));
+       memcpy(p, &plen, sizeof(plen));
+       p += sizeof(plen);
+       memcpy(p, path, plen);
+       p += plen;
+       memcpy(p, &val, sizeof(val));
 
        return ps_sendcmd(ctx, ctx->ps_root_fd, PS_WRITEPATHUINT, 0, buf, len);
 }