vsio: Allow zero length options

The spec allows it and this is an oversight.

diff --git a/src/if-options.c b/src/if-options.c
index 9d644827a79cafde0c237689401ad7f3fa19210d..0984db918db0d2f07ab86643d4edb4ac567735ce 100644 (file)
--- a/src/if-options.c
+++ b/src/if-options.c
@@ -940,19 +940,18 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
 
                if (fp != NULL)
                        fp = strskipwhite(fp);
-               if (fp != NULL)
-                       p = strchr(fp, ',');
-               else
-                       p = NULL;
-               if (p == NULL || p[1] == '\0') {
+               if (fp == NULL) {
                        logerrx("invalid vendor format: %s", arg);
                        return -1;
                }
 
                /* Strip and preserve the comma */
-               *p = '\0';
+               p = strchr(fp, ',');
+               if (p != NULL)
+                       *p = '\0';
                i = (int)strtoi(fp, NULL, 0, 1, (intmax_t)opt_max, &e);
-               *p = ',';
+               if (p != NULL)
+                       *p = ',';
                if (e) {
                        logerrx("vendor option should be between"
                                " 1 and %zu inclusive",
@@ -960,9 +959,12 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
                        return -1;
                }
 
-               fp = p + 1;
+               if (p != NULL)
+                       fp = p + 1;
+               else
+                       fp = NULL;
 
-               if (fp) {
+               if (fp != NULL && *fp != '\0') {
                        if (inet_pton(AF_INET, fp, &addr) == 1) {
                                s = sizeof(addr.s_addr);
                                dl = (size_t)s;
@@ -988,12 +990,16 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
                                        return -1;
                                }
                                dl = (size_t)s;
-                               np = malloc(dl);
-                               if (np == NULL) {
-                                       logerr(__func__);
-                                       return -1;
+                               if (dl == 0)
+                                       np = NULL;
+                               else {
+                                       np = malloc(dl);
+                                       if (np == NULL) {
+                                               logerr(__func__);
+                                               return -1;
+                                       }
+                                       parse_string(np, dl, fp);
                                }
-                               parse_string(np, dl, fp);
                        }
                } else {
                        dl = 0;
@@ -1023,7 +1029,7 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
                    sl++, vsio_so++)
                        opt_max -= opt_header + vsio_so->len;
                if (opt_header + dl > opt_max) {
-                       logerrx("vsio is too big: %s", fp);
+                       logerrx("vsio is too big: %s", arg);
                        free(np);
                        return -1;
                }