1 /*
2  * lib/route/link/ppp.c		PPP Link Module
3  *
4  *	This library is free software; you can redistribute it and/or
5  *	modify it under the terms of the GNU Lesser General Public
6  *	License as published by the Free Software Foundation version 2.1
7  *	of the License.
8  *
9  * Copyright (c) 2016 Jonas Johansson <jonasj76@gmail.com>
10  */
11 
12 /**
13  * @ingroup link
14  * @defgroup ppp PPP
15  *
16  * @details
17  * \b Link Type Name: "ppp"
18  *
19  * @route_doc{link_ppp, PPP Documentation}
20  * @{
21  */
22 
23 #include <netlink/route/link/ppp.h>
24 
25 #include <netlink-private/netlink.h>
26 #include <netlink/netlink.h>
27 #include <netlink-private/route/link/api.h>
28 
29 /** @cond SKIP */
30 #define PPP_ATTR_FD		(1<<0)
31 
32 struct ppp_info
33 {
34 	int32_t			pi_fd;
35 	uint32_t		ce_mask;
36 };
37 
38 /** @endcond */
39 
40 static struct nla_policy ppp_nl_policy[IFLA_PPP_MAX+1] = {
41 	[IFLA_PPP_DEV_FD]	= { .type = NLA_S32 },
42 };
43 
ppp_alloc(struct rtnl_link * link)44 static int ppp_alloc(struct rtnl_link *link)
45 {
46 	struct ppp_info *info;
47 
48 	if (link->l_info)
49 		memset(link->l_info, 0, sizeof(*info));
50 	else {
51 		if ((info = calloc(1, sizeof(*info))) == NULL)
52 			return -NLE_NOMEM;
53 
54 		link->l_info = info;
55 	}
56 
57 	return 0;
58 }
59 
ppp_parse(struct rtnl_link * link,struct nlattr * data,struct nlattr * xstats)60 static int ppp_parse(struct rtnl_link *link, struct nlattr *data,
61                          struct nlattr *xstats)
62 {
63 	struct nlattr *tb[IFLA_PPP_MAX+1];
64 	struct ppp_info *info;
65 	int err;
66 
67 	NL_DBG(3, "Parsing PPP link info\n");
68 
69 	if ((err = nla_parse_nested(tb, IFLA_PPP_MAX, data, ppp_nl_policy)) < 0)
70 		goto errout;
71 
72 	if ((err = ppp_alloc(link)) < 0)
73 		goto errout;
74 
75 	info = link->l_info;
76 
77 	if (tb[IFLA_PPP_DEV_FD]) {
78 		info->pi_fd = nla_get_s32(tb[IFLA_PPP_DEV_FD]);
79 		info->ce_mask |= PPP_ATTR_FD;
80 	}
81 
82 	err = 0;
83 errout:
84 	return err;
85 }
86 
ppp_free(struct rtnl_link * link)87 static void ppp_free(struct rtnl_link *link)
88 {
89 	free(link->l_info);
90 	link->l_info = NULL;
91 }
92 
ppp_clone(struct rtnl_link * dst,struct rtnl_link * src)93 static int ppp_clone(struct rtnl_link *dst, struct rtnl_link *src)
94 {
95 	struct ppp_info *vdst, *vsrc = src->l_info;
96 	int err;
97 
98 	dst->l_info = NULL;
99 	if ((err = rtnl_link_set_type(dst, "ppp")) < 0)
100 		return err;
101 	vdst = dst->l_info;
102 
103 	if (!vdst || !vsrc)
104 		return -NLE_NOMEM;
105 
106 	memcpy(vdst, vsrc, sizeof(struct ppp_info));
107 
108 	return 0;
109 }
110 
ppp_put_attrs(struct nl_msg * msg,struct rtnl_link * link)111 static int ppp_put_attrs(struct nl_msg *msg, struct rtnl_link *link)
112 {
113 	struct ppp_info *info = link->l_info;
114 	struct nlattr *data;
115 
116 	if (!(data = nla_nest_start(msg, IFLA_INFO_DATA)))
117 		return -NLE_MSGSIZE;
118 
119 	if (info->ce_mask & PPP_ATTR_FD)
120 		NLA_PUT_S32(msg, IFLA_PPP_DEV_FD, info->pi_fd);
121 
122 	nla_nest_end(msg, data);
123 
124 nla_put_failure:
125 
126 	return 0;
127 }
128 
129 static struct rtnl_link_info_ops ppp_info_ops = {
130 	.io_name		= "ppp",
131 	.io_alloc		= ppp_alloc,
132 	.io_parse		= ppp_parse,
133 	.io_clone		= ppp_clone,
134 	.io_put_attrs		= ppp_put_attrs,
135 	.io_free		= ppp_free,
136 };
137 
138 /** @cond SKIP */
139 #define IS_PPP_LINK_ASSERT(link) \
140 	if ((link)->l_info_ops != &ppp_info_ops) { \
141 		APPBUG("Link is not a PPP link. set type \"ppp\" first."); \
142 		return -NLE_OPNOTSUPP; \
143 	}
144 /** @endcond */
145 
146 /**
147  * @name PPP Object
148  * @{
149  */
150 
151 /**
152  * Allocate link object of type PPP
153  *
154  * @return Allocated link object or NULL.
155  */
rtnl_link_ppp_alloc(void)156 struct rtnl_link *rtnl_link_ppp_alloc(void)
157 {
158 	struct rtnl_link *link;
159 	int err;
160 
161 	if (!(link = rtnl_link_alloc()))
162 		return NULL;
163 
164 	if ((err = rtnl_link_set_type(link, "ppp")) < 0) {
165 		rtnl_link_put(link);
166 		return NULL;
167 	}
168 
169 	return link;
170 }
171 
172 /**
173  * Set PPP file descriptor
174  * @arg link		Link object
175  * @arg flags		PPP file descriptor
176  *
177  * @return 0 on success or a negative error code.
178  */
rtnl_link_ppp_set_fd(struct rtnl_link * link,int32_t fd)179 int rtnl_link_ppp_set_fd(struct rtnl_link *link, int32_t fd)
180 {
181 	struct ppp_info *info = link->l_info;
182 
183 	IS_PPP_LINK_ASSERT(link);
184 
185 	info->pi_fd |= fd;
186 	info->ce_mask |= PPP_ATTR_FD;
187 
188 	return 0;
189 }
190 
191 /**
192  * Get PPP file descriptor
193  * @arg link		Link object
194  *
195  * @return PPP file descriptor, 0 if not set or a negative error code.
196  */
rtnl_link_ppp_get_fd(struct rtnl_link * link,int32_t * fd)197 int rtnl_link_ppp_get_fd(struct rtnl_link *link, int32_t *fd)
198 {
199 	struct ppp_info *info = link->l_info;
200 
201 	IS_PPP_LINK_ASSERT(link);
202 
203 	if (!(info->ce_mask & PPP_ATTR_FD))
204 		return -NLE_NOATTR;
205 
206 	if (fd)
207 		*fd = info->pi_fd;
208 
209 	return 0;
210 }
211 
212 /** @} */
213 
ppp_init(void)214 static void __init ppp_init(void)
215 {
216 	rtnl_link_register_info(&ppp_info_ops);
217 }
218 
ppp_exit(void)219 static void __exit ppp_exit(void)
220 {
221 	rtnl_link_unregister_info(&ppp_info_ops);
222 }
223 
224 /** @} */
225