feat: identify the device with an origin SD-ELEMENT

SolidSyslogOriginSd (RFC 5424 section 7.2) carrying software, swVersion and
enterpriseId. The ip PARAM is left out: the address the collector sees is the one
that reached it.

  Flash      +11,972 B    (+396 on the previous stage)
  RAM         +7,136 B         (+44)
  Log stack     +448 B  (unchanged)
  Service       +736 B  (unchanged)

It lands after the store rather than before it. While a record went straight out,
"who sent this" was implied by the connection it arrived on; once records can
replay hours later that stops being true, and the record has to say so itself.

enterpriseId 32473 is the number reserved for documentation by RFC 5612. A device
shipping for real registers its own with IANA. It is defined in
app/syslog/SyslogEnterprise.h rather than beside the element that carries it,
because the number identifies the vendor and not the logger — anything else this
product puts its own name on wants the same one, and one definition cannot drift
from itself.

The record is now 245 bytes, against the 256-byte cap this device set when its
records were shorter.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: DavidCozens

README.md

@@ -10,16 +10,16 @@ It builds on a baseline that simulates the sort of device you might be adding th
 measures itself: see [docs/baseline.md](docs/baseline.md) for what the baseline is, how the
 figures are made, and how to run it.
 
-## This stage — File store
+## This stage — Origin
 
-Records spool to a block store on the volume the device already mounts — four blocks, one file
-each — instead of being held only in memory. The service task drains the ring into the store and
-sends from there, so a failed send costs a retry rather than the record. The CRC-16 written with
-each record catches corruption at rest, not tampering.
+The record carries an `origin` SD-ELEMENT naming the software, its version and the vendor's IANA
+enterprise number, so it identifies its sender instead of leaving the collector to infer that from
+the source address — which matters once the store replays records hours after the event. The `ip`
+PARAM is left out: the address the collector sees is still the one that reached it.
 
 <!-- STAGE-COST:START (generated by scripts/gen-cost-table.py — do not edit by hand) -->
 
-**Cost above baseline: Flash +11,576 B, RAM +7,092 B.**
+**Cost above baseline: Flash +11,972 B, RAM +7,136 B.**
 
 <!-- STAGE-COST:END -->
 
@@ -44,6 +44,7 @@ committed as [`run-report.md`](run-report.md), and rewritten by every stage.
 | TCP | records the network retransmits instead of dropping, and a send that fails when the collector is gone | +7,320 | +5,856 |
 | Time quality | a timestamp the collector knows how far to trust, and an uptime that tells a reboot from a counter wrap | +7,612 | +5,880 |
 | File store | records that survive a failed send, spooled to disk with a checksum at rest | +11,576 | +7,092 |
+| Origin | the device named in the record itself, not inferred from the source address | +11,972 | +7,136 |
 
 *Deltas are bytes above the baseline, which is itself Flash 350,308 B, RAM 111,192 B.*
 

app/syslog/Syslog.c

@@ -24,10 +24,12 @@
 #include "SolidSyslogLwipRawResolver.h"
 #include "SolidSyslogLwipRawTcpStream.h"
 #include "SolidSyslogMetaSd.h"
+#include "SolidSyslogOriginSd.h"
 #include "SolidSyslogStdAtomicCounter.h"
 #include "SolidSyslogStreamSender.h"
 #include "SolidSyslogTimeQuality.h"
 #include "SolidSyslogTimeQualitySd.h"
+#include "SyslogEnterprise.h"
 #include "SyslogFields.h"
 
 #include "lwip/tcpip.h"
@@ -53,11 +55,14 @@
 #define SYSLOG_STORE_PREFIX "syslog"
 #define SYSLOG_STORE_BLOCKS 4U
 
+#define SYSLOG_SOFTWARE "solid-syslog-example"
+#define SYSLOG_SW_VERSION "0.1.0"
+
 static struct SolidSyslog* s_logger = NULL;
 static uint8_t s_ring[SOLIDSYSLOG_CIRCULAR_BUFFER_RING_BYTES(SYSLOG_BUFFER_RECORDS)];
 
 /* The logger reads these on every record, so they outlive Syslog_Start. */
-static struct SolidSyslogStructuredData* s_sd[2];
+static struct SolidSyslogStructuredData* s_sd[3];
 
 /* One reading at boot, then free-running on the tick — enough to stamp a record,
  * not synchronisation. */
@@ -122,6 +127,15 @@ void Syslog_Start(void)
     s_sd[0] = SolidSyslogMetaSd_Create(&metaConfig);
     s_sd[1] = SolidSyslogTimeQualitySd_Create(SyslogTimeQuality);
 
+    /* No ip: the address the collector sees is the one that reached it, until a
+     * relay makes that untrue. */
+    struct SolidSyslogOriginSdConfig originConfig = {
+        .Software = SYSLOG_SOFTWARE,
+        .SwVersion = SYSLOG_SW_VERSION,
+        .EnterpriseId = SYSLOG_ENTERPRISE_ID,
+    };
+    s_sd[2] = SolidSyslogOriginSd_Create(&originConfig);
+
     /* Oldest discarded when the ceiling is reached: a device that cannot reach its
      * collector should keep the newest evidence, not stop logging. */
     struct SolidSyslogBlockStoreConfig storeConfig = {

app/syslog/SyslogEnterprise.h

@@ -0,0 +1,12 @@
+/* This product's IANA Private Enterprise Number. It identifies the vendor, not
+ * the logger, so it lives on its own rather than beside any one element that
+ * carries it.
+ *
+ * 32473 is reserved for documentation (RFC 5612). Register your own at
+ * https://www.iana.org/assignments/enterprise-numbers/ */
+#ifndef APP_SYSLOG_ENTERPRISE_H
+#define APP_SYSLOG_ENTERPRISE_H
+
+#define SYSLOG_ENTERPRISE_ID "32473"
+
+#endif /* APP_SYSLOG_ENTERPRISE_H */

measurements/origin.csv

@@ -0,0 +1,13 @@
+# origin figures (bytes) — captured by scripts/run.sh (CAPTURE=1).
+# The device reads measurements/Baseline.csv as its frozen baseline and reports current-minus-Baseline.
+flash_text,361640
+flash_data,640
+static_bss,117688
+heap_used,4440
+mbedtls_peak,21336
+mbedtls_free,11432
+lwip_mem_free,7576
+lwip_pbufs_free,13
+stack_log,568
+stack_service,788
+stack_harness,2848

measurements/stages.tsv

@@ -21,3 +21,4 @@ buffered	Buffered	logging that returns immediately, with the send moved off the
 tcp	TCP	records the network retransmits instead of dropping, and a send that fails when the collector is gone
 time-quality	Time quality	a timestamp the collector knows how far to trust, and an uptime that tells a reboot from a counter wrap
 file-store	File store	records that survive a failed send, spooled to disk with a checksum at rest
+origin	Origin	the device named in the record itself, not inferred from the source address

run-report.md

@@ -1,4 +1,4 @@
-# solid-syslog-example — run (file-store)
+# solid-syslog-example — run (origin)
 
 ## Device (self-measured)
 
@@ -10,14 +10,14 @@
 [device]   first record logged: yes
 [report] --- SolidSyslog cost above baseline (simulated existing application) ---
 [report] key,current,baseline,used_above_baseline
-[report] flash_text,361252,349992,11260
-[report] flash_data,632,316,316
-[report] static_bss,117652,110876,6776
+[report] flash_text,361640,349992,11648
+[report] flash_data,640,316,324
+[report] static_bss,117688,110876,6812
 [report] heap_used,4440,4440,0
-[report] mbedtls_peak,21276,21332,-56
-[report] mbedtls_free,11492,11436,56
+[report] mbedtls_peak,21336,21332,4
+[report] mbedtls_free,11432,11436,-4
 [report] lwip_mem_free,7576,7576,0
-[report] lwip_pbufs_free,14,14,0
+[report] lwip_pbufs_free,13,14,-1
 [report] stack_log,568,120,448
 [report] stack_service,788,52,736
 [report] stack_harness,2848,2840,8
@@ -29,7 +29,7 @@
 
 ```text
    text	   data	    bss	    dec	    hex	filename
- 361244	    640	 117652	 479536	  75130	/w/build/baseline-cross/baseline.elf
+ 361632	    648	 117688	 479968	  752e0	/w/build/baseline-cross/baseline.elf
 ```
 
 ## Listeners (proved before the device ran)
@@ -47,21 +47,21 @@
 ## Collector (syslog-ng) received
 
 ```text
-wire   <134>1 2026-07-29T08:06:15.410000Z 10.0.2.15 solid-syslog-example - BOOT [meta sequenceId="1" sysUpTime="241"][timeQuality tzKnown="1" isSynced="0"] device started
-parsed PRIORITY=134 TIMESTAMP=2026-07-29T08:06:15+00:00 HOSTNAME=10.0.2.15 APP_NAME=solid-syslog-example PROCID= MSGID=BOOT STRUCTURED_DATA=[meta sequenceId="1" sysUpTime="241"][timeQuality tzKnown="1" isSynced="0"] MSG=device started
+wire   <134>1 2026-07-29T08:21:38.360000Z 10.0.2.15 solid-syslog-example - BOOT [meta sequenceId="1" sysUpTime="236"][timeQuality tzKnown="1" isSynced="0"][origin software="solid-syslog-example" swVersion="0.1.0" enterpriseId="32473"] device started
+parsed PRIORITY=134 TIMESTAMP=2026-07-29T08:21:38+00:00 HOSTNAME=10.0.2.15 APP_NAME=solid-syslog-example PROCID= MSGID=BOOT STRUCTURED_DATA=[meta sequenceId="1" sysUpTime="236"][timeQuality tzKnown="1" isSynced="0"][origin software="solid-syslog-example" swVersion="0.1.0" enterpriseId="32473"] MSG=device started
 ```
 
-## Self-check (vs measurements/file-store.csv)
+## Self-check (vs measurements/origin.csv)
 
 ```text
-  OK    flash_text: 361252 (expected 361252, Δ0)
-  OK    flash_data: 632 (expected 632, Δ0)
-  OK    static_bss: 117652 (expected 117652, Δ0)
+  OK    flash_text: 361640 (expected 361640, Δ0)
+  OK    flash_data: 640 (expected 640, Δ0)
+  OK    static_bss: 117688 (expected 117688, Δ0)
   OK    heap_used: 4440 (expected 4440, Δ0)
-  OK    mbedtls_peak: 21276 (expected 21276, Δ0)
-  OK    mbedtls_free: 11492 (expected 11492, Δ0)
+  OK    mbedtls_peak: 21336 (expected 21336, Δ0)
+  OK    mbedtls_free: 11432 (expected 11432, Δ0)
   OK    lwip_mem_free: 7576 (expected 7576, Δ0)
-  OK    lwip_pbufs_free: 14 (expected 14, Δ0)
+  OK    lwip_pbufs_free: 13 (expected 13, Δ0)
   OK    stack_log: 568 (expected 568, Δ0)
   OK    stack_service: 788 (expected 788, Δ0)
   OK    stack_harness: 2848 (expected 2848, Δ0)