options: Define parse_nstring and use it

Makes the code easier to read.
While here, use sizeof rather than size constants to make it
more clear of the length of the property we're copying to.

diff --git a/src/if-options.c b/src/if-options.c
index 4fc706109fbd20a0e0295d80aab3a433d4526cf0..b30264912af1c608fdf0c149e8db6063cb50ac63 100644 (file)
--- a/src/if-options.c
+++ b/src/if-options.c
@@ -287,6 +287,7 @@ add_environ(char ***array, const char *value, int uniq)
 #define PARSE_STRING_NULL      1
 #define PARSE_HWADDR           2
 #define parse_string(a, b, c) parse_str((a), (b), (c), PARSE_STRING)
+#define parse_nstring(a, b, c) parse_str((a), (b), (c), PARSE_STRING_NULL)
 #define parse_hwaddr(a, b, c) parse_str((a), (b), (c), PARSE_HWADDR)
 static ssize_t
 parse_str(char *sbuf, size_t slen, const char *str, int flags)
@@ -723,7 +724,7 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
                ARG_REQUIRED;
                if (ifo->script != default_script)
                        free(ifo->script);
-               s = parse_str(NULL, 0, arg, PARSE_STRING_NULL);
+               s = parse_nstring(NULL, 0, arg);
                if (s == 0) {
                        ifo->script = NULL;
                        break;
@@ -734,7 +735,7 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
                        logerr(__func__);
                        return -1;
                }
-               s = parse_str(ifo->script, dl, arg, PARSE_STRING_NULL);
+               s = parse_nstring(ifo->script, dl, arg);
                if (s == -1 ||
                    ifo->script[0] == '\0' ||
                    strcmp(ifo->script, "/dev/null") == 0)
@@ -755,7 +756,7 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
                        ifo->options |= DHCPCD_HOSTNAME;
                        break;
                }
-               s = parse_string(ifo->hostname, HOSTNAME_MAX_LEN, arg);
+               s = parse_nstring(ifo->hostname, sizeof(ifo->hostname), arg);
                if (s == -1) {
                        logerr("%s: hostname", __func__);
                        return -1;
@@ -764,7 +765,6 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
                        logerrx("hostname cannot begin with .");
                        return -1;
                }
-               ifo->hostname[s] = '\0';
                if (ifo->hostname[0] == '\0')
                        ifo->options &= ~DHCPCD_HOSTNAME;
                else
@@ -882,9 +882,9 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
                }
                break;
        case 'u':
-               s = USERCLASS_MAX_LEN - ifo->userclass[0] - 1;
+               dl = sizeof(ifo->userclass) - ifo->userclass[0] - 1;
                s = parse_string((char *)ifo->userclass +
-                   ifo->userclass[0] + 2, (size_t)s, arg);
+                   ifo->userclass[0] + 2, dl, arg);
                if (s == -1) {
                        logerr("userclass");
                        return -1;