snmp: add helper functions to read data from rtu

Added functions were copied from rtu_stat Signed-off-by: Michal Wasiak <michal.wasiak@gmail.com>

snmp: add helper functions to read data from rtu
Added functions were copied from rtu_stat Signed-off-by: Michal Wasiak <michal.wasiak@gmail.com>
d82cfc23 · Michal Wasiak · Adam Wujek · 0633d243 · d82cfc23 · d82cfc23
Commit d82cfc23 authored Oct 08, 2020 by Michal Wasiak Committed by Adam Wujek Oct 29, 2020
Hide whitespace changes
Inline Side-by-side

Showing with 99 additions and 1 deletion

snmp_shmem.c userspace/snmpd/snmp_shmem.c +91 -0

snmp_shmem.h userspace/snmpd/snmp_shmem.h +8 -1

No files found.
--- a/userspace/snmpd/snmp_shmem.c
+++ b/userspace/snmpd/snmp_shmem.c
@@ -244,3 +244,94 @@ void init_shm(void){
 		sleep(1);
 	}
 }
+
+int shmem_rtu_read_vlans(struct rtu_vlan_table_entry *vlan_tab_local)
+{
+	unsigned ii;
+	unsigned retries = 0;
+	struct rtu_vlan_table_entry *vlan_tab_shm;
+	struct rtu_shmem_header *rtu_hdr;
+
+	rtu_hdr = (void *)rtud_head + rtud_head->data_off;
+	vlan_tab_shm = wrs_shm_follow(rtud_head, rtu_hdr->vlans);
+	if (!vlan_tab_shm)
+		return -2;
+	/* read data, with the sequential lock to have all data consistent */
+	while (1) {
+		ii = wrs_shm_seqbegin(rtud_head);
+		memcpy(vlan_tab_local, vlan_tab_shm,
+		       NUM_VLANS * sizeof(*vlan_tab_shm));
+		retries++;
+		if (retries > 100)
+			return -1;
+		if (!wrs_shm_seqretry(rtud_head, ii))
+			break; /* consistent read */
+		usleep(1000);
+	}
+
+	return 0;
+}
+
+/* Read filtes from rtud's shm, convert hashtable to regular table */
+int shmem_rtu_read_htab(struct rtu_filtering_entry *rtu_htab_local, int *read_entries)
+{
+	unsigned ii;
+	unsigned retries = 0;
+	struct rtu_filtering_entry *htab_shm;
+	struct rtu_shmem_header *rtu_hdr;
+	struct rtu_filtering_entry *empty;
+
+	rtu_hdr = (void *)rtud_head + rtud_head->data_off;
+	htab_shm = wrs_shm_follow(rtud_head, rtu_hdr->filters);
+	if (!htab_shm)
+		return -2;
+
+	/* Read data, with the sequential lock to have all data consistent */
+	while (1) {
+		ii = wrs_shm_seqbegin(rtud_head);
+		memcpy(rtu_htab_local, htab_shm,
+		       RTU_BUCKETS * HTAB_ENTRIES * sizeof(*htab_shm));
+		retries++;
+		if (retries > 100)
+			return -1;
+		if (!wrs_shm_seqretry(rtud_head, ii))
+			break; /* consistent read */
+		usleep(1000);
+	}
+
+	/* Convert hash table to ordered table. Table will be qsorted later,
+	 * no need to qsort entire table */
+	*read_entries = 0;
+	empty = rtu_htab_local;
+	for (ii = 0; ii < RTU_BUCKETS * HTAB_ENTRIES; ii++) {
+		if (rtu_htab_local[ii].valid) {
+			memcpy(empty, &rtu_htab_local[ii], sizeof(*htab_shm));
+			empty++;
+			(*read_entries)++;
+		}
+	}
+
+	return 0;
+}
+
+/* Compare entries by by MAC */
+int cmp_rtu_entries_mac(const void *p1, const void *p2)
+{
+	const struct rtu_filtering_entry *e1 = p1;
+	const struct rtu_filtering_entry *e2 = p2;
+
+	return memcmp(e1->mac, e2->mac, 6);
+}
+
+/* Compare rtu entries by FID then by MAC */
+int cmp_rtu_entries_fid_mac(const void *p1, const void *p2)
+{
+	const struct rtu_filtering_entry *e1 = p1;
+	const struct rtu_filtering_entry *e2 = p2;
+
+	if (e1->fid > e2->fid)
+	    return 1;
+	else if (e1->fid < e2->fid)
+	    return -1;
+	return memcmp(e1->mac, e2->mac, 6);
+}
--- a/userspace/snmpd/snmp_shmem.h
+++ b/userspace/snmpd/snmp_shmem.h
@@ -21,11 +21,18 @@ extern parentDS_t *ppsi_parentDS;
 extern defaultDS_t *ppsi_defaultDS;

 /* RTUd */
-struct wrs_shm_head *rtud_head;
+extern struct wrs_shm_head *rtud_head;

 void init_shm();
 int shmem_ready_hald(void);
 int shmem_ready_ppsi(void);
 int shmem_ready_rtud(void);
+int shmem_rtu_read_htab(struct rtu_filtering_entry *rtu_htab_local, int *read_entries);
+int shmem_rtu_read_vlans(struct rtu_vlan_table_entry *vlan_tab_local);
+/* Compare entries by by MAC */
+int cmp_rtu_entries_mac(const void *p1, const void *p2);
+/* Compare rtu entries by FID then by MAC */
+int cmp_rtu_entries_fid_mac(const void *p1, const void *p2);
+

 #endif /* WRS_SNMP_SHMEM_H */