networkd: rework duid_{type,duid_type,duid,duid_len} setting

Separate fields are replaced  with a struct.

Second second duid type field is removed. The first field was used to carry
the result of DUIDType= configuration, and the second was either a copy of
this, or contained the type extracted from DuidRawData. The semantics are changed
so that the type specified in DUIDType is always used. DUIDRawData= no longer
overrides the type setting.

The networkd code is now more constrained than the sd-dhcp code:
DUIDRawData cannot have 0 length, length 0 is treated the same as unsetting.
Likewise, it is not possible to set a DUIDType=0. If it ever becomes necessary
to set type=0 or a zero-length duid, the code can be changed to support that.
Nevertheless, I think that's unlikely.

This addresses #3127 § 1 and 3.

v2:
- rename DUID.duid, DUID.duid_len to DUID.raw_data, DUID.raw_data_len

1 files changed, 14 insertions, 73 deletions

diff --git a/src/network/networkd-conf.c b/src/network/networkd-conf.c
index 70f0121d6d..1b2047f8f4 100644
--- a/src/network/networkd-conf.c
+++ b/src/network/networkd-conf.c
@@ -41,7 +41,7 @@ static const char* const duid_type_table[_DUID_TYPE_MAX] = {
         [DUID_TYPE_LLT]  = "link-layer-time",
         [DUID_TYPE_EN]   = "vendor",
         [DUID_TYPE_LL]   = "link-layer",
-        [DUID_TYPE_UUID] = "uuid"
+        [DUID_TYPE_UUID] = "uuid",
 };
 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING(duid_type, DUIDType);
 DEFINE_CONFIG_PARSE_ENUM(config_parse_duid_type, duid_type, DUIDType, "Failed to parse DUID type");
@@ -58,69 +58,29 @@ int config_parse_duid_rawdata(
                 void *data,
                 void *userdata) {
 
-        int r;
-        char *cbyte;
-        const char *pduid = rvalue;
-        Manager *m = userdata;
-        Network *n = userdata;
-        DUIDType duidtype;
-        uint16_t dhcp_duid_type = 0;
-        uint8_t dhcp_duid[MAX_DUID_LEN];
-        size_t len, count = 0, duid_start_offset = 0, dhcp_duid_len = 0;
+        DUID *ret = data;
+        uint8_t raw_data[MAX_DUID_LEN];
+        unsigned count = 0;
 
         assert(filename);
         assert(lvalue);
         assert(rvalue);
-        assert(userdata);
+        assert(ret);
 
-        duidtype = (ltype == DUID_CONFIG_SOURCE_GLOBAL) ? m->duid_type : n->duid_type;
-
-        if (duidtype == _DUID_TYPE_INVALID)
-                duidtype = DUID_TYPE_RAW;
-
-        switch (duidtype) {
-
-        case DUID_TYPE_LLT:
-                /* RawData contains DUID-LLT link-layer address (offset 6) */
-                duid_start_offset = 6;
-                break;
-
-        case DUID_TYPE_EN:
-                /* RawData contains DUID-EN identifier (offset 4) */
-                duid_start_offset = 4;
-                break;
-
-        case DUID_TYPE_LL:
-                /* RawData contains DUID-LL link-layer address (offset 2) */
-                duid_start_offset = 2;
-                break;
-
-        case DUID_TYPE_UUID:
-                /* RawData specifies UUID (offset 0) - fall thru */
-
-        case DUID_TYPE_RAW:
-                /* First two bytes of RawData is DUID Type - fall thru */
-
-        default:
-                break;
-        }
-
-        if (duidtype != DUID_TYPE_RAW)
-                dhcp_duid_type = (uint16_t) duidtype;
-
-        /* RawData contains DUID in format " NN:NN:NN... " */
+        /* RawData contains DUID in format "NN:NN:NN..." */
         for (;;) {
-                int n1, n2;
+                int n1, n2, len, r;
                 uint32_t byte;
+                char *cbyte;
 
-                r = extract_first_word(&pduid, &cbyte, ":", 0);
+                r = extract_first_word(&rvalue, &cbyte, ":", 0);
                 if (r < 0) {
                         log_syntax(unit, LOG_ERR, filename, line, r, "Failed to read DUID, ignoring assignment: %s.", rvalue);
                         return 0;
                 }
                 if (r == 0)
                         break;
-                if (duid_start_offset + dhcp_duid_len >= MAX_DUID_LEN) {
+                if (count >= MAX_DUID_LEN) {
                         log_syntax(unit, LOG_ERR, filename, line, 0, "Max DUID length exceeded, ignoring assignment: %s.", rvalue);
                         return 0;
                 }
@@ -142,30 +102,11 @@ int config_parse_duid_rawdata(
                 }
 
                 byte = ((uint8_t) n1 << (4 * (len-1))) | (uint8_t) n2;
-
-                /* If DUID_TYPE_RAW, first two bytes hold DHCP DUID type code */
-                if (duidtype == DUID_TYPE_RAW && count < 2) {
-                        dhcp_duid_type |= (byte << (8 * (1 - count)));
-                        count++;
-                        continue;
-                }
-
-                dhcp_duid[duid_start_offset + dhcp_duid_len] = byte;
-                dhcp_duid_len++;
-        }
-
-        if (ltype == DUID_CONFIG_SOURCE_GLOBAL) {
-                m->duid_type = duidtype;
-                m->dhcp_duid_type = dhcp_duid_type;
-                m->dhcp_duid_len = dhcp_duid_len;
-                memcpy(&m->dhcp_duid[duid_start_offset], dhcp_duid, dhcp_duid_len);
-        } else {
-                /* DUID_CONFIG_SOURCE_NETWORK */
-                n->duid_type = duidtype;
-                n->dhcp_duid_type = dhcp_duid_type;
-                n->dhcp_duid_len = dhcp_duid_len;
-                memcpy(&n->dhcp_duid[duid_start_offset], dhcp_duid, dhcp_duid_len);
+                raw_data[count++] = byte;
         }
 
+        assert_cc(sizeof(raw_data) == sizeof(ret->raw_data));
+        memcpy(ret->raw_data, raw_data, count);
+        ret->raw_data_len = count;
         return 0;
 }