udhcp: support string user options, closes 10946

function                                             old     new   delta
udhcp_str2optset                                     536     628     +92
packed_usage                                       32757   32760      +3
udhcpc_main                                         2708    2692     -16
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 95/-16)             Total: 79 bytes

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

3 files changed, 50 insertions, 43 deletions

diff --git a/networking/udhcp/common.c b/networking/udhcp/common.c
index d3eea5def..fbf9c6878 100644
--- a/networking/udhcp/common.c
+++ b/networking/udhcp/common.c
@@ -378,34 +378,24 @@ int FAST_FUNC udhcp_str2nip(const char *str, void *arg)
  * Called to parse "udhcpc -x OPTNAME:OPTVAL"
  * and to parse udhcpd.conf's "opt OPTNAME OPTVAL" directives.
  */
-/* helper for the helper */
-static char *allocate_tempopt_if_needed(
+/* helper: add an option to the opt_list */
+static NOINLINE void attach_option(
+                struct option_set **opt_list,
                 const struct dhcp_optflag *optflag,
                 char *buffer,
-                int *length_p)
+                int length)
 {
+        struct option_set *existing;
         char *allocated = NULL;
+
         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_BIN) {
                 const char *end;
                 allocated = xstrdup(buffer); /* more than enough */
                 end = hex2bin(allocated, buffer, 255);
                 if (errno)
                         bb_error_msg_and_die("malformed hex string '%s'", buffer);
-                *length_p = end - allocated;
+                length = end - allocated;
         }
-        return allocated;
-}
-/* helper: add an option to the opt_list */
-static NOINLINE void attach_option(
-                struct option_set **opt_list,
-                const struct dhcp_optflag *optflag,
-                char *buffer,
-                int length)
-{
-        struct option_set *existing;
-        char *allocated;
-
-        allocated = allocate_tempopt_if_needed(optflag, buffer, &length);
 #if ENABLE_FEATURE_UDHCP_RFC3397
         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_DNS_STRING) {
                 /* reuse buffer and length for RFC1035-formatted string */
@@ -463,12 +453,12 @@ static NOINLINE void attach_option(
 int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg, const struct dhcp_optflag *optflags, const char *option_strings)
 {
         struct option_set **opt_list = arg;
-        char *opt, *val;
+        char *opt;
         char *str;
         const struct dhcp_optflag *optflag;
-        struct dhcp_optflag bin_optflag;
+        struct dhcp_optflag userdef_optflag;
         unsigned optcode;
-        int retval, length;
+        int retval;
         /* IP_PAIR needs 8 bytes, STATIC_ROUTES needs 9 max */
         char buffer[9] ALIGNED(4);
         uint16_t *result_u16 = (uint16_t *) buffer;
@@ -476,28 +466,40 @@ int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg, const struct dh
 
         /* Cheat, the only *const* str possible is "" */
         str = (char *) const_str;
-        opt = strtok(str, " \t=");
+        opt = strtok(str, " \t=:");
         if (!opt)
                 return 0;
 
         optcode = bb_strtou(opt, NULL, 0);
         if (!errno && optcode < 255) {
-                /* Raw (numeric) option code */
-                bin_optflag.flags = OPTION_BIN;
-                bin_optflag.code = optcode;
-                optflag = &bin_optflag;
+                /* Raw (numeric) option code.
+                 * Initially assume binary (hex-str), but if "str" or 'str'
+                 * is seen later, switch to STRING.
+                 */
+                userdef_optflag.flags = OPTION_BIN;
+                userdef_optflag.code = optcode;
+                optflag = &userdef_optflag;
         } else {
                 optflag = &optflags[udhcp_option_idx(opt, option_strings)];
         }
 
+        /* Loop to handle OPTION_LIST case, else execute just once */
         retval = 0;
         do {
-                val = strtok(NULL, ", \t");
+                int length;
+                char *val;
+
+                if (optflag->flags == OPTION_BIN)
+                        val = trim(strtok(NULL, "")); /* do not split "'q w e'" */
+                else
+                        val = strtok(NULL, ", \t");
                 if (!val)
                         break;
+
                 length = dhcp_option_lengths[optflag->flags & OPTION_TYPE_MASK];
                 retval = 0;
                 opt = buffer; /* new meaning for variable opt */
+
                 switch (optflag->flags & OPTION_TYPE_MASK) {
                 case OPTION_IP:
                         retval = udhcp_str2nip(val, buffer);
@@ -510,6 +512,7 @@ int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg, const struct dh
                         if (retval)
                                 retval = udhcp_str2nip(val, buffer + 4);
                         break;
+case_OPTION_STRING:
                 case OPTION_STRING:
                 case OPTION_STRING_HOST:
 #if ENABLE_FEATURE_UDHCP_RFC3397
@@ -577,12 +580,26 @@ int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg, const struct dh
                         }
                         break;
                 }
-                case OPTION_BIN: /* handled in attach_option() */
+                case OPTION_BIN:
+                        /* Raw (numeric) option code. Is it a string? */
+                        if (val[0] == '"' || val[0] == '\'') {
+                                char delim = val[0];
+                                char *end = last_char_is(val + 1, delim);
+                                if (end) {
+                                        *end = '\0';
+                                        val++;
+                                        userdef_optflag.flags = OPTION_STRING;
+                                        goto case_OPTION_STRING;
+                                }
+                        }
+                        /* No: hex-str option, handled in attach_option() */
                         opt = val;
                         retval = 1;
+                        break;
                 default:
                         break;
                 }
+
                 if (retval)
                         attach_option(opt_list, optflag, opt, length);
         } while (retval && (optflag->flags & OPTION_LIST));
diff --git a/networking/udhcp/d6_dhcpc.c b/networking/udhcp/d6_dhcpc.c
index 289df66ee..85d9da724 100644
--- a/networking/udhcp/d6_dhcpc.c
+++ b/networking/udhcp/d6_dhcpc.c
@@ -1063,6 +1063,7 @@ static void client_background(void)
 //usage:     "\n                        -x hostname:bbox - option 12"
 //usage:     "\n                        -x lease:3600 - option 51 (lease time)"
 //usage:     "\n                        -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
+//usage:     "\n                        -x 14:'\"dumpfile\"' - option 14 (shell-quoted)"
 //usage:        IF_UDHCP_VERBOSE(
 //usage:     "\n        -v              Verbose"
 //usage:        )
@@ -1155,15 +1156,9 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
                 }
         }
         while (list_x) {
-                char *optstr = llist_pop(&list_x);
-                char *colon = strchr(optstr, ':');
-                if (colon)
-                        *colon = ' ';
-                /* now it looks similar to udhcpd's config file line:
-                 * "optname optval", using the common routine: */
+                char *optstr = xstrdup(llist_pop(&list_x));
                 udhcp_str2optset(optstr, &client_config.options, d6_optflags, d6_option_strings);
-                if (colon)
-                        *colon = ':'; /* restore it for NOMMU reexec */
+                free(optstr);
         }
 
         if (d6_read_interface(client_config.interface,
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 90b07bf4b..bd9e8fdc2 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -1224,6 +1224,7 @@ static void client_background(void)
 //usage:     "\n                        -x hostname:bbox - option 12"
 //usage:     "\n                        -x lease:3600 - option 51 (lease time)"
 //usage:     "\n                        -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
+//usage:     "\n                        -x 14:'\"dumpfile\"' - option 14 (shell-quoted)"
 //usage:     "\n        -F NAME         Ask server to update DNS mapping for NAME"
 //usage:     "\n        -V VENDOR       Vendor identifier (default 'udhcp VERSION')"
 //usage:     "\n        -C              Don't send MAC as client identifier"
@@ -1335,15 +1336,9 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                 }
         }
         while (list_x) {
-                char *optstr = llist_pop(&list_x);
-                char *colon = strchr(optstr, ':');
-                if (colon)
-                        *colon = ' ';
-                /* now it looks similar to udhcpd's config file line:
-                 * "optname optval", using the common routine: */
+                char *optstr = xstrdup(llist_pop(&list_x));
                 udhcp_str2optset(optstr, &client_config.options, dhcp_optflags, dhcp_option_strings);
-                if (colon)
-                        *colon = ':'; /* restore it for NOMMU reexec */
+                free(optstr);
         }
 
         if (udhcp_read_interface(client_config.interface,