xref: /linux/tools/testing/selftests/bpf/progs/verifier_lwt.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Converted from tools/testing/selftests/bpf/verifier/lwt.c */
3 
4 #include <linux/bpf.h>
5 #include <bpf/bpf_helpers.h>
6 #include "bpf_misc.h"
7 
8 SEC("lwt_in")
9 __description("invalid direct packet write for LWT_IN")
10 __failure __msg("cannot write into packet")
11 __naked void packet_write_for_lwt_in(void)
12 {
13 	asm volatile ("					\
14 	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
15 	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
16 	r0 = r2;					\
17 	r0 += 8;					\
18 	if r0 > r3 goto l0_%=;				\
19 	*(u8*)(r2 + 0) = r2;				\
20 l0_%=:	r0 = 0;						\
21 	exit;						\
22 "	:
23 	: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
24 	  __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
25 	: __clobber_all);
26 }
27 
28 SEC("lwt_out")
29 __description("invalid direct packet write for LWT_OUT")
30 __failure __msg("cannot write into packet")
31 __naked void packet_write_for_lwt_out(void)
32 {
33 	asm volatile ("					\
34 	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
35 	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
36 	r0 = r2;					\
37 	r0 += 8;					\
38 	if r0 > r3 goto l0_%=;				\
39 	*(u8*)(r2 + 0) = r2;				\
40 l0_%=:	r0 = 0;						\
41 	exit;						\
42 "	:
43 	: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
44 	  __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
45 	: __clobber_all);
46 }
47 
48 SEC("lwt_xmit")
49 __description("direct packet write for LWT_XMIT")
50 __success __retval(0)
51 __naked void packet_write_for_lwt_xmit(void)
52 {
53 	asm volatile ("					\
54 	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
55 	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
56 	r0 = r2;					\
57 	r0 += 8;					\
58 	if r0 > r3 goto l0_%=;				\
59 	*(u8*)(r2 + 0) = r2;				\
60 l0_%=:	r0 = 0;						\
61 	exit;						\
62 "	:
63 	: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
64 	  __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
65 	: __clobber_all);
66 }
67 
68 SEC("lwt_in")
69 __description("direct packet read for LWT_IN")
70 __success __retval(0)
71 __naked void packet_read_for_lwt_in(void)
72 {
73 	asm volatile ("					\
74 	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
75 	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
76 	r0 = r2;					\
77 	r0 += 8;					\
78 	if r0 > r3 goto l0_%=;				\
79 	r0 = *(u8*)(r2 + 0);				\
80 l0_%=:	r0 = 0;						\
81 	exit;						\
82 "	:
83 	: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
84 	  __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
85 	: __clobber_all);
86 }
87 
88 SEC("lwt_out")
89 __description("direct packet read for LWT_OUT")
90 __success __retval(0)
91 __naked void packet_read_for_lwt_out(void)
92 {
93 	asm volatile ("					\
94 	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
95 	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
96 	r0 = r2;					\
97 	r0 += 8;					\
98 	if r0 > r3 goto l0_%=;				\
99 	r0 = *(u8*)(r2 + 0);				\
100 l0_%=:	r0 = 0;						\
101 	exit;						\
102 "	:
103 	: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
104 	  __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
105 	: __clobber_all);
106 }
107 
108 SEC("lwt_xmit")
109 __description("direct packet read for LWT_XMIT")
110 __success __retval(0)
111 __naked void packet_read_for_lwt_xmit(void)
112 {
113 	asm volatile ("					\
114 	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
115 	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
116 	r0 = r2;					\
117 	r0 += 8;					\
118 	if r0 > r3 goto l0_%=;				\
119 	r0 = *(u8*)(r2 + 0);				\
120 l0_%=:	r0 = 0;						\
121 	exit;						\
122 "	:
123 	: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
124 	  __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
125 	: __clobber_all);
126 }
127 
128 SEC("lwt_xmit")
129 __description("overlapping checks for direct packet access")
130 __success __retval(0)
131 __naked void checks_for_direct_packet_access(void)
132 {
133 	asm volatile ("					\
134 	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
135 	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
136 	r0 = r2;					\
137 	r0 += 8;					\
138 	if r0 > r3 goto l0_%=;				\
139 	r1 = r2;					\
140 	r1 += 6;					\
141 	if r1 > r3 goto l0_%=;				\
142 	r0 = *(u16*)(r2 + 6);				\
143 l0_%=:	r0 = 0;						\
144 	exit;						\
145 "	:
146 	: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
147 	  __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
148 	: __clobber_all);
149 }
150 
151 SEC("lwt_xmit")
152 __description("make headroom for LWT_XMIT")
153 __success __retval(0)
154 __naked void make_headroom_for_lwt_xmit(void)
155 {
156 	asm volatile ("					\
157 	r6 = r1;					\
158 	r2 = 34;					\
159 	r3 = 0;						\
160 	call %[bpf_skb_change_head];			\
161 	/* split for s390 to succeed */			\
162 	r1 = r6;					\
163 	r2 = 42;					\
164 	r3 = 0;						\
165 	call %[bpf_skb_change_head];			\
166 	r0 = 0;						\
167 	exit;						\
168 "	:
169 	: __imm(bpf_skb_change_head)
170 	: __clobber_all);
171 }
172 
173 SEC("socket")
174 __description("invalid access of tc_classid for LWT_IN")
175 __failure __msg("invalid bpf_context access")
176 __failure_unpriv
177 __naked void tc_classid_for_lwt_in(void)
178 {
179 	asm volatile ("					\
180 	r0 = *(u32*)(r1 + %[__sk_buff_tc_classid]);	\
181 	exit;						\
182 "	:
183 	: __imm_const(__sk_buff_tc_classid, offsetof(struct __sk_buff, tc_classid))
184 	: __clobber_all);
185 }
186 
187 SEC("socket")
188 __description("invalid access of tc_classid for LWT_OUT")
189 __failure __msg("invalid bpf_context access")
190 __failure_unpriv
191 __naked void tc_classid_for_lwt_out(void)
192 {
193 	asm volatile ("					\
194 	r0 = *(u32*)(r1 + %[__sk_buff_tc_classid]);	\
195 	exit;						\
196 "	:
197 	: __imm_const(__sk_buff_tc_classid, offsetof(struct __sk_buff, tc_classid))
198 	: __clobber_all);
199 }
200 
201 SEC("socket")
202 __description("invalid access of tc_classid for LWT_XMIT")
203 __failure __msg("invalid bpf_context access")
204 __failure_unpriv
205 __naked void tc_classid_for_lwt_xmit(void)
206 {
207 	asm volatile ("					\
208 	r0 = *(u32*)(r1 + %[__sk_buff_tc_classid]);	\
209 	exit;						\
210 "	:
211 	: __imm_const(__sk_buff_tc_classid, offsetof(struct __sk_buff, tc_classid))
212 	: __clobber_all);
213 }
214 
215 SEC("lwt_in")
216 __description("check skb->tc_classid half load not permitted for lwt prog")
217 __failure __msg("invalid bpf_context access")
218 __naked void not_permitted_for_lwt_prog(void)
219 {
220 	asm volatile (
221 	"r0 = 0;"
222 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
223 	"r0 = *(u16*)(r1 + %[__sk_buff_tc_classid]);"
224 #else
225 	"r0 = *(u16*)(r1 + %[__imm_0]);"
226 #endif
227 	"exit;"
228 	:
229 	: __imm_const(__imm_0, offsetof(struct __sk_buff, tc_classid) + 2),
230 	  __imm_const(__sk_buff_tc_classid, offsetof(struct __sk_buff, tc_classid))
231 	: __clobber_all);
232 }
233 
234 char _license[] SEC("license") = "GPL";
235