xref: /illumos-gate/usr/src/uts/common/fs/smbsrv/smb2_session_setup.c (revision 9e6ea9213154ef7c52331a70f1ebe24181db43f1)
1 /*
2  * This file and its contents are supplied under the terms of the
3  * Common Development and Distribution License ("CDDL"), version 1.0.
4  * You may only use this file in accordance with the terms of version
5  * 1.0 of the CDDL.
6  *
7  * A full copy of the text of the CDDL should have accompanied this
8  * source.  A copy of the CDDL is also available via the Internet at
9  * http://www.illumos.org/license/CDDL.
10  */
11 
12 /*
13  * Copyright 2017 Nexenta Systems, Inc.  All rights reserved.
14  */
15 
16 /*
17  * Dispatch function for SMB2_SESSION_SETUP
18  *
19  * Note that the Capabilities supplied in this request are an inferior
20  * subset of those given to us previously in the SMB2 Negotiate request.
21  * We need to remember the full set of capabilities from SMB2 Negotiate,
22  * and therefore ignore the subset of capabilities supplied here.
23  */
24 
25 #include <smbsrv/smb2_kproto.h>
26 
27 static void smb2_ss_adjust_credits(smb_request_t *);
28 
29 smb_sdrc_t
30 smb2_session_setup(smb_request_t *sr)
31 {
32 	smb_arg_sessionsetup_t	*sinfo;
33 	uint16_t StructureSize;
34 	uint8_t  Flags;
35 	uint8_t  SecurityMode;
36 	uint32_t Capabilities;	/* ignored - see above */
37 	uint32_t Channel;
38 	uint16_t SecBufOffset;
39 	uint16_t SecBufLength;
40 	uint64_t PrevSessionId;
41 	uint16_t SessionFlags;
42 	uint32_t status;
43 	int skip;
44 	int rc = 0;
45 
46 	sinfo = smb_srm_zalloc(sr, sizeof (smb_arg_sessionsetup_t));
47 	sr->sr_ssetup = sinfo;
48 
49 	rc = smb_mbc_decodef(
50 	    &sr->smb_data, "wbbllwwq",
51 	    &StructureSize,	/* w */
52 	    &Flags,		/* b */
53 	    &SecurityMode,	/* b */
54 	    &Capabilities,	/* l */
55 	    &Channel,		/* l */
56 	    &SecBufOffset,	/* w */
57 	    &SecBufLength,	/* w */
58 	    &PrevSessionId);	/* q */
59 	if (rc)
60 		return (SDRC_ERROR);
61 
62 	/*
63 	 * We're normally positioned at the security buffer now,
64 	 * but there could be some padding before it.
65 	 */
66 	skip = (SecBufOffset + sr->smb2_cmd_hdr) -
67 	    sr->smb_data.chain_offset;
68 	if (skip < 0)
69 		return (SDRC_ERROR);
70 	if (skip > 0)
71 		(void) smb_mbc_decodef(&sr->smb_data, "#.", skip);
72 
73 	/*
74 	 * Get the security buffer
75 	 */
76 	sinfo->ssi_iseclen = SecBufLength;
77 	sinfo->ssi_isecblob = smb_srm_zalloc(sr, sinfo->ssi_iseclen);
78 	rc = smb_mbc_decodef(&sr->smb_data, "#c",
79 	    sinfo->ssi_iseclen, sinfo->ssi_isecblob);
80 	if (rc)
81 		return (SDRC_ERROR);
82 
83 	/*
84 	 * Decoded everything.  Dtrace probe,
85 	 * then no more early returns.
86 	 */
87 	DTRACE_SMB2_START(op__SessionSetup, smb_request_t *, sr);
88 
89 	/*
90 	 * The real auth. work happens in here.
91 	 */
92 	status = smb_authenticate_ext(sr);
93 
94 	SecBufOffset = SMB2_HDR_SIZE + 8;
95 	SecBufLength = sinfo->ssi_oseclen;
96 	SessionFlags = 0;
97 
98 	switch (status) {
99 
100 	case NT_STATUS_SUCCESS:	/* Authenticated */
101 		if (sr->uid_user->u_flags & SMB_USER_FLAG_GUEST)
102 			SessionFlags |= SMB2_SESSION_FLAG_IS_GUEST;
103 		if (sr->uid_user->u_flags & SMB_USER_FLAG_ANON)
104 			SessionFlags |= SMB2_SESSION_FLAG_IS_NULL;
105 		smb2_ss_adjust_credits(sr);
106 		break;
107 
108 	/*
109 	 * This is not really an error, but tells the client
110 	 * it should send another session setup request.
111 	 * Not smb2_put_error because we send a payload.
112 	 */
113 	case NT_STATUS_MORE_PROCESSING_REQUIRED:
114 		sr->smb2_status = status;
115 		break;
116 
117 	default:
118 		SecBufLength = 0;
119 		sr->smb2_status = status;
120 		break;
121 	}
122 
123 	/* sr->smb2_status set above */
124 	DTRACE_SMB2_DONE(op__SessionSetup, smb_request_t *, sr);
125 
126 	/*
127 	 * SMB2 Session Setup reply
128 	 */
129 
130 	rc = smb_mbc_encodef(
131 	    &sr->reply,
132 	    "wwww#c",
133 	    9,	/* StructSize */	/* w */
134 	    SessionFlags,		/* w */
135 	    SecBufOffset,		/* w */
136 	    SecBufLength,		/* w */
137 	    SecBufLength,		/* # */
138 	    sinfo->ssi_osecblob);	/* c */
139 	if (rc)
140 		sr->smb2_status = NT_STATUS_INTERNAL_ERROR;
141 
142 	return (SDRC_SUCCESS);
143 }
144 
145 /*
146  * After a successful authentication, raise s_max_credits up to the
147  * normal maximum that clients are allowed to request.  Also, if we
148  * haven't yet given them their initial credits, do that now.
149  *
150  * Normally, clients will request some credits with session setup,
151  * but in case they don't request enough to raise s_cur_credits
152  * up to the configured initial_credits, increase the requested
153  * credits of this SR sufficiently to make that happen.  The actual
154  * increase happens in the dispatch code after we return.
155  */
156 static void
157 smb2_ss_adjust_credits(smb_request_t *sr)
158 {
159 	smb_session_t *s = sr->session;
160 
161 	mutex_enter(&s->s_credits_mutex);
162 	s->s_max_credits = s->s_cfg.skc_maximum_credits;
163 
164 	if (s->s_cur_credits < s->s_cfg.skc_initial_credits) {
165 		uint16_t grant;
166 
167 		/* How many credits we want to grant with this SR. */
168 		grant = s->s_cfg.skc_initial_credits - s->s_cur_credits;
169 
170 		/*
171 		 * Do we need to increase the smb2_credit_request?
172 		 * One might prefer to read this expression as:
173 		 *	((credit_request - credit_charge) < grant)
174 		 * but we know credit_charge == 1 and would rather not
175 		 * deal with a possibly negative value on the left,
176 		 * so adding credit_charge to both sides...
177 		 */
178 		if (sr->smb2_credit_request < (grant + 1)) {
179 			sr->smb2_credit_request = (grant + 1);
180 		}
181 	}
182 
183 	mutex_exit(&s->s_credits_mutex);
184 }
185