xref: /illumos-gate/usr/src/uts/common/io/ppp/sppptun/sppptun_mod.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
1 /*
2  * sppptun_mod.c - modload support for PPP multiplexing tunnel driver.
3  *
4  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
5  * Use is subject to license terms.
6  */
7 
8 
9 #include <sys/types.h>
10 #include <sys/param.h>
11 #include <sys/stat.h>
12 #include <sys/systm.h>
13 #include <sys/socket.h>
14 #include <sys/stream.h>
15 #include <sys/stropts.h>
16 #include <sys/time.h>
17 #include <sys/conf.h>
18 #include <sys/kstat.h>
19 #include <sys/sunddi.h>
20 #include <net/sppptun.h>
21 #include <netinet/in.h>
22 
23 #include "sppptun_mod.h"
24 
25 /*
26  * Descriptions for flags values in cb_flags field:
27  *
28  * D_MTQPAIR:
29  *    An inner perimeter that spans the queue pair.
30  * D_MTOUTPERIM:
31  *    An outer perimeter that spans over all queues in the module.
32  * D_MTOCEXCL:
33  *    Open & close procedures are entered exclusively at outer perimeter.
34  * D_MTPUTSHARED:
35  *    Entry to put procedures are done with SHARED (reader) acess
36  *    and not EXCLUSIVE (writer) access.
37  *
38  * Therefore:
39  *
40  * 1. Open and close procedures are entered with EXCLUSIVE (writer)
41  *    access at the inner perimeter, and with EXCLUSIVE (writer) access at
42  *    the outer perimeter.
43  *
44  * 2. Put procedures are entered with SHARED (reader) access at the inner
45  *    perimeter, and with SHARED (reader) access at the outer perimeter.
46  *
47  * 3. Service procedures are entered with EXCLUSIVE (writer) access at
48  *    the inner perimeter, and with SHARED (reader) access at the
49  *    outer perimeter.
50  *
51  * Do not attempt to modify these flags unless the entire corresponding
52  * driver code is changed to accomodate the newly represented MT-STREAMS
53  * flags. Doing so without making proper modifications to the driver code
54  * will severely impact the intended driver behavior, and thus may affect
55  * the system's stability and performance.
56  */
57 
58 static int	tun_attach(dev_info_t *, ddi_attach_cmd_t);
59 static int	tun_detach(dev_info_t *, ddi_detach_cmd_t);
60 static int	tun_info(dev_info_t *, ddi_info_cmd_t, void *, void **);
61 
62 static dev_info_t *tun_dev_info;
63 
64 DDI_DEFINE_STREAM_OPS(sppptun_ops,			\
65 	nulldev, nulldev,				\
66 	tun_attach, tun_detach, nodev, tun_info,	\
67 	D_NEW | D_MP | D_MTQPAIR | D_MTOUTPERIM | D_MTOCEXCL | D_MTPUTSHARED, \
68 	&sppptun_tab, ddi_quiesce_not_supported);
69 
70 /*
71  * This is the loadable module wrapper.
72  */
73 #include <sys/modctl.h>
74 
75 /*
76  * Module linkage information for the kernel.
77  */
78 static struct fmodsw sppptun_fmodsw = {
79 	PPP_TUN_NAME,
80 	&sppptun_tab,
81 	D_NEW | D_MP | D_MTQPAIR | D_MTOUTPERIM | D_MTOCEXCL | D_MTPUTSHARED
82 };
83 
84 static struct modldrv modldrv = {
85 	&mod_driverops,
86 	(char *)sppptun_driver_description,
87 	&sppptun_ops
88 };
89 
90 static struct modlstrmod modlstrmod = {
91 	&mod_strmodops,
92 	(char *)sppptun_module_description,
93 	&sppptun_fmodsw
94 };
95 
96 static struct modlinkage modlinkage = {
97 	MODREV_1,
98 	(void *)&modlstrmod,
99 	(void *)&modldrv,
100 	NULL
101 };
102 
103 int
104 _init(void)
105 {
106 	int retv;
107 
108 	sppptun_init();
109 	if ((retv = mod_install(&modlinkage)) == 0)
110 		sppptun_tcl_init();
111 	return (retv);
112 }
113 
114 int
115 _fini(void)
116 {
117 	int retv;
118 
119 	if ((retv = sppptun_tcl_fintest()) != 0)
120 		return (retv);
121 	retv = mod_remove(&modlinkage);
122 	if (retv != 0)
123 		return (retv);
124 	sppptun_tcl_fini();
125 	return (0);
126 }
127 
128 int
129 _info(struct modinfo *modinfop)
130 {
131 	return (mod_info(&modlinkage, modinfop));
132 }
133 
134 /*
135  * tun_attach()
136  *
137  * Description:
138  *    Attach a PPP tunnel driver to the system.
139  */
140 static int
141 tun_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
142 {
143 	if (cmd != DDI_ATTACH)
144 		return (DDI_FAILURE);
145 	if (ddi_create_minor_node(dip, PPP_TUN_NAME, S_IFCHR, 0, DDI_PSEUDO,
146 	    CLONE_DEV) == DDI_FAILURE) {
147 		ddi_remove_minor_node(dip, NULL);
148 		return (DDI_FAILURE);
149 	}
150 	tun_dev_info = dip;
151 	return (DDI_SUCCESS);
152 }
153 
154 /*
155  * tun_detach()
156  *
157  * Description:
158  *    Detach an interface to the system.
159  */
160 static int
161 tun_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
162 {
163 	if (cmd != DDI_DETACH)
164 		return (DDI_FAILURE);
165 	tun_dev_info = NULL;
166 	ddi_remove_minor_node(dip, NULL);
167 	return (DDI_SUCCESS);
168 }
169 
170 /*
171  * tun_info()
172  *
173  * Description:
174  *    Translate "dev_t" to a pointer to the associated "dev_info_t".
175  */
176 /* ARGSUSED */
177 static int
178 tun_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
179 	void **result)
180 {
181 	int	rc;
182 
183 	switch (infocmd) {
184 	case DDI_INFO_DEVT2DEVINFO:
185 		if (tun_dev_info == NULL) {
186 			rc = DDI_FAILURE;
187 		} else {
188 			*result = (void *)tun_dev_info;
189 			rc = DDI_SUCCESS;
190 		}
191 		break;
192 	case DDI_INFO_DEVT2INSTANCE:
193 		*result = NULL;
194 		rc = DDI_SUCCESS;
195 		break;
196 	default:
197 		rc = DDI_FAILURE;
198 		break;
199 	}
200 	return (rc);
201 }
202