udhcp: abort if we see unknown option, and show valid options if so

function                                             old     new   delta
udhcp_option_idx                                       -      77     +77
udhcp_str2optset                                     366     351     -15
udhcpc_main                                         2845    2801     -44
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/2 up/down: 77/-59)             Total: 18 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/networking/udhcp/common.c b/networking/udhcp/common.c
index 9316774ffe0a31864920ccb93fb1916463f52013..6e8ec3e64877a343f8fd3e08853bc5465b6dc484 100644 (file)
--- a/networking/udhcp/common.c
+++ b/networking/udhcp/common.c
@@ -146,6 +146,25 @@ static void log_option(const char *pfx, const uint8_t *opt)
 # define log_option(pfx, opt) ((void)0)
 #endif
 
+unsigned FAST_FUNC udhcp_option_idx(const char *name)
+{
+       int n = index_in_strings(dhcp_option_strings, name);
+       if (n >= 0)
+               return n;
+
+       {
+               char buf[sizeof(dhcp_option_strings)];
+               char *d = buf;
+               const char *s = dhcp_option_strings;
+               while (s < dhcp_option_strings + sizeof(dhcp_option_strings) - 2) {
+                       *d++ = (*s == '\0' ? ' ' : *s);
+                       s++;
+               }
+               *d = '\0';
+               bb_error_msg_and_die("unknown option '%s', known options: %s", name, buf);
+       }
+}
+
 /* get an option with bounds checking (warning, result is not aligned). */
 uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code)
 {
@@ -372,7 +391,7 @@ int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg)
        char *opt, *val, *endptr;
        char *str;
        const struct dhcp_option *option;
-       int retval, length, idx;
+       int retval, length;
        char buffer[8] ALIGNED(4);
        uint16_t *result_u16 = (uint16_t *) buffer;
        uint32_t *result_u32 = (uint32_t *) buffer;
@@ -383,10 +402,7 @@ int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg)
        if (!opt)
                return 0;
 
-       idx = index_in_strings(dhcp_option_strings, opt); /* NB: was strcasecmp! */
-       if (idx < 0)
-               return 0;
-       option = &dhcp_options[idx];
+       option = &dhcp_options[udhcp_option_idx(opt)];
 
        retval = 0;
        do {

diff --git a/networking/udhcp/common.h b/networking/udhcp/common.h
index b4e8b5d431ce195e145f2f7210be6c25b449a1f4..1c5afa6f93a9e92499f1b6316e2aaf43e78df7fb 100644 (file)
--- a/networking/udhcp/common.h
+++ b/networking/udhcp/common.h
@@ -169,6 +169,8 @@ extern const struct dhcp_option dhcp_options[];
 extern const char dhcp_option_strings[];
 extern const uint8_t dhcp_option_lengths[];
 
+unsigned FAST_FUNC udhcp_option_idx(const char *name);
+
 uint8_t *udhcp_get_option(struct dhcp_packet *packet, int code) FAST_FUNC;
 int udhcp_end_option(uint8_t *optionptr) FAST_FUNC;
 void udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt) FAST_FUNC;

diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 478ca5c21c1ef8b8592c61db23e3229876b56553..c36d4180bba314c95dcda449d56a90f4efcd5fb9 100644 (file)
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -879,21 +879,17 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                client_config.no_default_options = 1;
        while (list_O) {
                char *optstr = llist_pop(&list_O);
-               int n = index_in_strings(dhcp_option_strings, optstr);
-               if (n < 0)
-                       bb_error_msg_and_die("unknown option '%s'", optstr);
+               unsigned n = udhcp_option_idx(optstr);
                n = dhcp_options[n].code;
                client_config.opt_mask[n >> 3] |= 1 << (n & 7);
        }
        while (list_x) {
-               int n;
+               unsigned n;
                char *optstr = llist_pop(&list_x);
                char *colon = strchr(optstr, ':');
                if (colon)
                        *colon = '\0';
-               n = index_in_strings(dhcp_option_strings, optstr);
-               if (n < 0)
-                       bb_error_msg_and_die("unknown option '%s'", optstr);
+               n = udhcp_option_idx(optstr);
                if (colon)
                        *colon = ' ';
                udhcp_str2optset(optstr, &client_config.options);