Added checksum functionality and some documentation in gw.h

diff --git a/cangw.c b/cangw.c
index d8757e3c01bcf07b3838ca9fe9cbeeab2981224d..8f99f9b6b4eb0d006ba10bade552cba8c6f3c0d1 100644 (file)
--- a/cangw.c
+++ b/cangw.c
@@ -135,16 +135,17 @@ void print_cs_xor(struct cgw_csum_xor *cs_xor)
 {
        printf("-x %d:%d:%d:%02X ",
               cs_xor->from_idx, cs_xor->to_idx,
-              cs_xor->result_idx, cs_xor->prefix_value);
+              cs_xor->result_idx, cs_xor->init_xor_val);
 }
 
 void print_cs_crc8(struct cgw_csum_crc8 *cs_crc8)
 {
        int i;
 
-       printf("-c %d:%d:%d:",
+       printf("-c %d:%d:%d:%02X:%02X:",
               cs_crc8->from_idx, cs_crc8->to_idx,
-              cs_crc8->result_idx);
+              cs_crc8->result_idx, cs_crc8->init_crc_val,
+              cs_crc8->final_xor_val);
 
        for (i = 0; i < 256; i++)
                printf("%02X", cs_crc8->crctab[i]);
@@ -246,18 +247,25 @@ int parse_mod(char *optarg, struct modattr *modmsg)
                ptr++;
        }
 
-       if ((sscanf(++ptr, "%lx.%hhd.%16s",
-                   (long unsigned int *)&modmsg->cf.can_id,
-                   (unsigned char *)&modmsg->cf.can_dlc, hexdata) != 3) ||
-           (modmsg->cf.can_dlc > 8))
+       if (sscanf(++ptr, "%lx.%hhx.%16s",
+                  (long unsigned int *)&modmsg->cf.can_id,
+                  (unsigned char *)&modmsg->cf.can_dlc, hexdata) != 3)
                return 5;
 
-       if (strlen(hexdata) != 16)
+       /* 4-bit masks can have values from 0 to 0xF */ 
+       if (modmsg->cf.can_dlc > 0xF)
                return 6;
 
-       if (b64hex(hexdata, &modmsg->cf.data[0], 8))
+       /* but when setting CAN_DLC the value has to be limited to 8 */
+       if (modmsg->instruction == CGW_MOD_SET && modmsg->cf.can_dlc > 8)
                return 7;
 
+       if (strlen(hexdata) != 16)
+               return 8;
+
+       if (b64hex(hexdata, &modmsg->cf.data[0], 8))
+               return 9;
+
        return 0; /* ok */
 }
 
@@ -515,7 +523,7 @@ int main(int argc, char **argv)
                case 'x':
                        if (sscanf(optarg, "%hhd:%hhd:%hhd:%hhx",
                                   &cs_xor.from_idx, &cs_xor.to_idx,
-                                  &cs_xor.result_idx, &cs_xor.prefix_value) == 4) {
+                                  &cs_xor.result_idx, &cs_xor.init_xor_val) == 4) {
                                have_cs_xor = 1;
                        } else {
                                printf("Bad XOR checksum definition '%s'.\n", optarg);
@@ -524,9 +532,10 @@ int main(int argc, char **argv)
                        break;
 
                case 'c':
-                       if ((sscanf(optarg, "%hhd:%hhd:%hhd:%512s",
+                       if ((sscanf(optarg, "%hhd:%hhd:%hhd:%hhx:%hhx:%512s",
                                    &cs_crc8.from_idx, &cs_crc8.to_idx,
-                                   &cs_crc8.result_idx, crc8tab) == 4) &&
+                                   &cs_crc8.result_idx, &cs_crc8.init_crc_val,
+                                   &cs_crc8.final_xor_val, crc8tab) == 6) &&
                            (strlen(crc8tab) == 512) &&
                            (b64hex(crc8tab, (unsigned char *)&cs_crc8.crctab, 256) == 0)) {
                                have_cs_crc8 = 1;
@@ -616,12 +625,12 @@ int main(int argc, char **argv)
        if (have_filter)
                addattr_l(&req.nh, sizeof(req), CGW_FILTER, &filter, sizeof(filter));
 
-       if (have_cs_xor)
-               addattr_l(&req.nh, sizeof(req), CGW_CS_XOR, &cs_xor, sizeof(cs_xor));
-
        if (have_cs_crc8)
                addattr_l(&req.nh, sizeof(req), CGW_CS_CRC8, &cs_crc8, sizeof(cs_crc8));
 
+       if (have_cs_xor)
+               addattr_l(&req.nh, sizeof(req), CGW_CS_XOR, &cs_xor, sizeof(cs_xor));
+
        /*
         * a better example code
         * modmsg.modtype = CGW_MOD_ID;