From: Martijn van Duren Subject: Re: snmpd: move smi_getticks to appl_sysuptime To: tech@openbsd.org Date: Tue, 28 Oct 2025 09:11:35 +0100 ping On Wed, 2025-10-08 at 12:27 +0200, Martijn van Duren wrote: > ping > > On Mon, 2024-03-18 at 18:22 +0100, Martijn van Duren wrote: > > smi_getticks is snmpd's current way of supplying the sysUpTime. SMI > > doesn't define the sysUpTime (that would be SNMPv2-MIB), so this > > placing is wrong. Another issue with it is that it uses gettimeofday, > > where CLOCK_MONOTONIC would be a better fit. > > > > The definition of sysUpTime is: > > "The time (in hundredths of a second) since the > > network management portion of the system was last > > re-initialized." > > Where I wasn't able to find a clear definition of "network management > > portion". However, the AgentX RFC2741 states in section 6.2.16: > > res.sysUpTime > > > > This field contains the current value of sysUpTime for the > > context indicated within the PDU to which this PDU is a > > response. > > Implying that the sysUpTime is at the very least on a per context basis. > > For this reason I went with placing the information in appl_context. > > > > Because of this the start time should be set when the context is > > created, implying that the context should be created during appl_init, > > instead of relying on a random query creating it (either AgentX setup, > > or an SNMP packet). > > > > As for the 'struct appl_context *' vs 'const char *', I've stuck > > with 'const char *' for consistency and keep things a bit more in > > line with the SNMP/AgentX protocol point of view. > > > > While here fix the types of sysORLastChange and sysORUpTime. > > > > OK? > > > > martijn@ > > > Index: application.c =================================================================== RCS file: /cvs/src/usr.sbin/snmpd/application.c,v diff -u -r1.43 application.c --- application.c 8 Feb 2024 17:34:09 -0000 1.43 +++ application.c 28 Oct 2025 08:10:38 -0000 @@ -28,6 +28,7 @@ #include #include #include +#include #include "application.h" #include "log.h" @@ -48,7 +49,7 @@ uint32_t aa_index; struct ber_oid aa_oid; char aa_descr[256]; - int aa_uptime; + uint32_t aa_uptime; TAILQ_ENTRY(appl_agentcap) aa_entry; }; @@ -57,9 +58,12 @@ char ac_name[APPL_CONTEXTNAME_MAX + 1]; RB_HEAD(appl_regions, appl_region) ac_regions; + TAILQ_HEAD(, appl_agentcap) ac_agentcaps; int ac_agentcap_lastid; - int ac_agentcap_lastchange; + uint32_t ac_agentcap_lastchange; + + struct timespec ac_starttime; TAILQ_ENTRY(appl_context) ac_entries; }; @@ -179,6 +183,8 @@ void appl_init(void) { + if (appl_context(NULL, 1) == NULL) + fatal("Failed to create default context"); appl_blocklist_init(); appl_internal_init(); appl_agentx_init(); @@ -220,7 +226,7 @@ } /* Always allow the default namespace */ - if (!create && name[0] != '\0') { + if (!create) { errno = ENOENT; return NULL; } @@ -235,6 +241,9 @@ ctx->ac_agentcap_lastchange = 0; TAILQ_INSERT_TAIL(&contexts, ctx, ac_entries); + + if (clock_gettime(CLOCK_MONOTONIC, &ctx->ac_starttime) == -1) + fatal("clock_gettime"); return ctx; } @@ -271,7 +280,7 @@ cap->aa_context = ctx; cap->aa_index = ++ctx->ac_agentcap_lastid; cap->aa_oid = *oid; - cap->aa_uptime = smi_getticks(); + cap->aa_uptime = appl_sysuptime(ctxname); if (strlcpy(cap->aa_descr, descr, sizeof(cap->aa_descr)) >= sizeof(cap->aa_descr)) { log_info("%s: Can't add agent capabilities %s: " @@ -331,8 +340,25 @@ appl_agentcap_free(struct appl_agentcap *cap) { TAILQ_REMOVE(&(cap->aa_context->ac_agentcaps), cap, aa_entry); - cap->aa_context->ac_agentcap_lastchange = smi_getticks(); + cap->aa_context->ac_agentcap_lastchange = + appl_sysuptime(cap->aa_context->ac_name); free(cap); +} + +uint32_t +appl_sysuptime(const char *ctxname) +{ + struct appl_context *ctx; + struct timespec now, uptime; + + if ((ctx = appl_context(ctxname, 0)) == NULL) + return 0; + + if (clock_gettime(CLOCK_MONOTONIC, &now) == -1) + fatal("clock_gettime"); + + timespecsub(&now, &ctx->ac_starttime, &uptime); + return uptime.tv_sec * 100 + uptime.tv_nsec / 10000000; } struct ber_element * Index: application.h =================================================================== RCS file: /cvs/src/usr.sbin/snmpd/application.h,v diff -u -r1.13 application.h --- application.h 12 Nov 2023 16:07:34 -0000 1.13 +++ application.h 28 Oct 2025 08:10:38 -0000 @@ -123,6 +123,7 @@ void appl_init(void); void appl_shutdown(void); struct appl_context *appl_context(const char *, int); +uint32_t appl_sysuptime(const char *); enum appl_error appl_addagentcaps(const char *, struct ber_oid *, const char *, struct appl_backend *); enum appl_error appl_removeagentcaps(const char *, struct ber_oid *, Index: application_agentx.c =================================================================== RCS file: /cvs/src/usr.sbin/snmpd/application_agentx.c,v diff -u -r1.16 application_agentx.c --- application_agentx.c 6 Feb 2024 12:44:27 -0000 1.16 +++ application_agentx.c 28 Oct 2025 08:10:38 -0000 @@ -423,7 +423,8 @@ case AX_PDU_TYPE_PING: ax_response(conn->conn_ax, pdu->ap_header.aph_sessionid, pdu->ap_header.aph_transactionid, - pdu->ap_header.aph_packetid, smi_getticks(), + pdu->ap_header.aph_packetid, + appl_sysuptime(pdu->ap_context.aos_string), APPL_ERROR_NOERROR, 0, NULL, 0); event_add(&(conn->conn_wev), NULL); break; @@ -433,7 +434,8 @@ ax_pdutype2string(pdu->ap_header.aph_type)); ax_response(conn->conn_ax, pdu->ap_header.aph_sessionid, pdu->ap_header.aph_transactionid, - pdu->ap_header.aph_packetid, smi_getticks(), + pdu->ap_header.aph_packetid, + appl_sysuptime(pdu->ap_context.aos_string), APPL_ERROR_PROCESSINGERROR, 1, pdu->ap_payload.ap_vbl.ap_varbind, pdu->ap_payload.ap_vbl.ap_nvarbind); @@ -455,8 +457,8 @@ fail: ax_response(conn->conn_ax, pdu->ap_header.aph_sessionid, pdu->ap_header.aph_transactionid, - pdu->ap_header.aph_packetid, smi_getticks(), - error, 0, NULL, 0); + pdu->ap_header.aph_packetid, + appl_sysuptime(pdu->ap_context.aos_string), error, 0, NULL, 0); event_add(&(conn->conn_wev), NULL); ax_pdu_free(pdu); @@ -565,13 +567,14 @@ ax_response(conn->conn_ax, session->sess_id, pdu->ap_header.aph_transactionid, pdu->ap_header.aph_packetid, - smi_getticks(), APPL_ERROR_NOERROR, 0, NULL, 0); + appl_sysuptime(NULL), APPL_ERROR_NOERROR, 0, NULL, 0); event_add(&(conn->conn_wev), NULL); return; fail: ax_response(conn->conn_ax, 0, pdu->ap_header.aph_transactionid, - pdu->ap_header.aph_packetid, 0, error, 0, NULL, 0); + pdu->ap_header.aph_packetid, appl_sysuptime(NULL), + error, 0, NULL, 0); event_add(&(conn->conn_wev), NULL); if (session != NULL) free(session->sess_descr.aos_string); @@ -597,7 +600,7 @@ ax_response(conn->conn_ax, pdu->ap_header.aph_sessionid, pdu->ap_header.aph_transactionid, pdu->ap_header.aph_packetid, - smi_getticks(), error, 0, NULL, 0); + appl_sysuptime(NULL), error, 0, NULL, 0); event_add(&(conn->conn_wev), NULL); if (error == APPL_ERROR_NOERROR) return; @@ -676,7 +679,7 @@ fail: ax_response(session->sess_conn->conn_ax, session->sess_id, pdu->ap_header.aph_transactionid, pdu->ap_header.aph_packetid, - smi_getticks(), error, 0, NULL, 0); + appl_sysuptime(pdu->ap_context.aos_string), error, 0, NULL, 0); event_add(&(session->sess_conn->conn_wev), NULL); } @@ -703,7 +706,7 @@ fail: ax_response(session->sess_conn->conn_ax, session->sess_id, pdu->ap_header.aph_transactionid, pdu->ap_header.aph_packetid, - smi_getticks(), error, 0, NULL, 0); + appl_sysuptime(pdu->ap_context.aos_string), error, 0, NULL, 0); event_add(&(session->sess_conn->conn_wev), NULL); } @@ -835,7 +838,7 @@ fail: ax_response(session->sess_conn->conn_ax, session->sess_id, pdu->ap_header.aph_transactionid, pdu->ap_header.aph_packetid, - smi_getticks(), error, 0, NULL, 0); + appl_sysuptime(pdu->ap_context.aos_string), error, 0, NULL, 0); event_add(&(session->sess_conn->conn_wev), NULL); } @@ -860,7 +863,7 @@ fail: ax_response(session->sess_conn->conn_ax, session->sess_id, pdu->ap_header.aph_transactionid, pdu->ap_header.aph_packetid, - smi_getticks(), error, 0, NULL, 0); + appl_sysuptime(pdu->ap_context.aos_string), error, 0, NULL, 0); event_add(&(session->sess_conn->conn_wev), NULL); } Index: application_internal.c =================================================================== RCS file: /cvs/src/usr.sbin/snmpd/application_internal.c,v diff -u -r1.12 application_internal.c --- application_internal.c 6 Feb 2024 12:44:27 -0000 1.12 +++ application_internal.c 28 Oct 2025 08:10:39 -0000 @@ -577,7 +577,7 @@ else if (ober_oid_cmp(&OID(MIB_sysOID, 0), oid) == 0) return ober_add_oid(NULL, &s->sys_oid); else if (ober_oid_cmp(&OID(MIB_sysUpTime, 0), oid) == 0) { - value = ober_add_integer(NULL, smi_getticks()); + value = ober_add_integer(NULL, appl_sysuptime(NULL)); ober_set_header(value, BER_CLASS_APPLICATION, SNMP_T_TIMETICKS); } else if (ober_oid_cmp(&OID(MIB_sysContact, 0), oid) == 0) return ober_add_string(NULL, s->sys_contact); Index: smi.c =================================================================== RCS file: /cvs/src/usr.sbin/snmpd/smi.c,v diff -u -r1.40 smi.c --- smi.c 6 Feb 2024 12:44:27 -0000 1.40 +++ smi.c 28 Oct 2025 08:10:39 -0000 @@ -62,23 +62,6 @@ RB_PROTOTYPE(keytree, oid, o_keyword, smi_key_cmp); struct keytree smi_keytree; -u_long -smi_getticks(void) -{ - struct timeval now, run; - u_long ticks; - - gettimeofday(&now, NULL); - if (timercmp(&now, &snmpd_env->sc_starttime, <=)) - return (0); - timersub(&now, &snmpd_env->sc_starttime, &run); - ticks = run.tv_sec * 100; - if (run.tv_usec) - ticks += run.tv_usec / 10000; - - return (ticks); -} - char * smi_oid2string(struct ber_oid *o, char *buf, size_t len, size_t skip) { Index: smi.h =================================================================== RCS file: /cvs/src/usr.sbin/snmpd/smi.h,v diff -u -r1.4 smi.h --- smi.h 21 Dec 2023 12:43:31 -0000 1.4 +++ smi.h 28 Oct 2025 08:10:39 -0000 @@ -22,6 +22,5 @@ struct ber_oid; char *smi_oid2string(struct ber_oid *, char *, size_t, size_t); -u_long smi_getticks(void); char *smi_print_element(struct ber_element *); char *smi_print_element_legacy(struct ber_element *); Index: snmpd.c =================================================================== RCS file: /cvs/src/usr.sbin/snmpd/snmpd.c,v diff -u -r1.52 snmpd.c --- snmpd.c 12 Apr 2024 14:17:42 -0000 1.52 +++ snmpd.c 28 Oct 2025 08:10:39 -0000 @@ -218,7 +218,6 @@ log_init(debug, LOG_DAEMON); log_setverbose(verbose); - gettimeofday(&env->sc_starttime, NULL); env->sc_engine_boots = 0; proc_init(ps, procs, nitems(procs), debug, argc0, argv0, proc_id); Index: snmpd.h =================================================================== RCS file: /cvs/src/usr.sbin/snmpd/snmpd.h,v diff -u -r1.120 snmpd.h --- snmpd.h 21 May 2024 05:00:48 -0000 1.120 +++ snmpd.h 28 Oct 2025 08:10:39 -0000 @@ -22,7 +22,6 @@ #include #include -#include #include #include #include @@ -402,7 +401,6 @@ const char *sc_confpath; struct addresslist sc_addresses; struct axmasterlist sc_agentx_masters; - struct timeval sc_starttime; u_int32_t sc_engine_boots; char sc_rdcommunity[SNMPD_MAXCOMMUNITYLEN]; Index: trap.c =================================================================== RCS file: /cvs/src/usr.sbin/snmpd/trap.c,v diff -u -r1.43 trap.c --- trap.c 6 Feb 2024 15:36:11 -0000 1.43 +++ trap.c 28 Oct 2025 08:10:39 -0000 @@ -24,9 +24,9 @@ #include #include +#include "application.h" #include "log.h" #include "mib.h" -#include "smi.h" #include "snmp.h" #include "snmpd.h" @@ -60,7 +60,7 @@ /* Add mandatory varbind elements */ trap = ober_add_sequence(NULL); vblist = ober_printf_elements(trap, "{Odt}{OO}", - &uptime, smi_getticks(), + &uptime, appl_sysuptime(NULL), BER_CLASS_APPLICATION, SNMP_T_TIMETICKS, &trapoid, oid); if (elm != NULL)