1/*
2 * Copyright (c) 2020 iXsystems, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 */
27
28#include <sys/list.h>
29#include <sys/mutex.h>
30#include <sys/procfs_list.h>
31
32typedef struct procfs_list_iter {
33	procfs_list_t *pli_pl;
34	void *pli_elt;
35} pli_t;
36
37void
38seq_printf(struct seq_file *f, const char *fmt, ...)
39{
40	va_list adx;
41
42	va_start(adx, fmt);
43	(void) vsnprintf(f->sf_buf, f->sf_size, fmt, adx);
44	va_end(adx);
45}
46
47static int
48procfs_list_update(kstat_t *ksp, int rw)
49{
50	procfs_list_t *pl = ksp->ks_private;
51
52	if (rw == KSTAT_WRITE)
53		pl->pl_clear(pl);
54
55	return (0);
56}
57
58static int
59procfs_list_data(char *buf, size_t size, void *data)
60{
61	pli_t *p;
62	void *elt;
63	procfs_list_t *pl;
64	struct seq_file f;
65
66	p = data;
67	pl = p->pli_pl;
68	elt = p->pli_elt;
69	free(p, M_TEMP);
70	f.sf_buf = buf;
71	f.sf_size = size;
72	return (pl->pl_show(&f, elt));
73}
74
75static void *
76procfs_list_addr(kstat_t *ksp, loff_t n)
77{
78	procfs_list_t *pl = ksp->ks_private;
79	void *elt = ksp->ks_private1;
80	pli_t *p = NULL;
81
82
83	if (n == 0)
84		ksp->ks_private1 = list_head(&pl->pl_list);
85	else if (elt)
86		ksp->ks_private1 = list_next(&pl->pl_list, elt);
87
88	if (ksp->ks_private1) {
89		p = malloc(sizeof (*p), M_TEMP, M_WAITOK);
90		p->pli_pl = pl;
91		p->pli_elt = ksp->ks_private1;
92	}
93
94	return (p);
95}
96
97void
98procfs_list_install(const char *module,
99    const char *submodule,
100    const char *name,
101    mode_t mode,
102    procfs_list_t *procfs_list,
103    int (*show)(struct seq_file *f, void *p),
104    int (*show_header)(struct seq_file *f),
105    int (*clear)(procfs_list_t *procfs_list),
106    size_t procfs_list_node_off)
107{
108	kstat_t *procfs_kstat;
109
110	mutex_init(&procfs_list->pl_lock, NULL, MUTEX_DEFAULT, NULL);
111	list_create(&procfs_list->pl_list,
112	    procfs_list_node_off + sizeof (procfs_list_node_t),
113	    procfs_list_node_off + offsetof(procfs_list_node_t, pln_link));
114	procfs_list->pl_show = show;
115	procfs_list->pl_show_header = show_header;
116	procfs_list->pl_clear = clear;
117	procfs_list->pl_next_id = 1;
118	procfs_list->pl_node_offset = procfs_list_node_off;
119
120	procfs_kstat =  kstat_create(module, 0, name, submodule,
121	    KSTAT_TYPE_RAW, 0, KSTAT_FLAG_VIRTUAL);
122
123	if (procfs_kstat) {
124		procfs_kstat->ks_lock = &procfs_list->pl_lock;
125		procfs_kstat->ks_ndata = UINT32_MAX;
126		procfs_kstat->ks_private = procfs_list;
127		procfs_kstat->ks_update = procfs_list_update;
128		kstat_set_seq_raw_ops(procfs_kstat, show_header,
129		    procfs_list_data, procfs_list_addr);
130		kstat_install(procfs_kstat);
131		procfs_list->pl_private = procfs_kstat;
132	}
133}
134
135void
136procfs_list_uninstall(procfs_list_t *procfs_list)
137{}
138
139void
140procfs_list_destroy(procfs_list_t *procfs_list)
141{
142	ASSERT(list_is_empty(&procfs_list->pl_list));
143	kstat_delete(procfs_list->pl_private);
144	list_destroy(&procfs_list->pl_list);
145	mutex_destroy(&procfs_list->pl_lock);
146}
147
148#define	NODE_ID(procfs_list, obj) \
149		(((procfs_list_node_t *)(((char *)obj) + \
150		(procfs_list)->pl_node_offset))->pln_id)
151
152void
153procfs_list_add(procfs_list_t *procfs_list, void *p)
154{
155	ASSERT(MUTEX_HELD(&procfs_list->pl_lock));
156	NODE_ID(procfs_list, p) = procfs_list->pl_next_id++;
157	list_insert_tail(&procfs_list->pl_list, p);
158}
159