1 // SPDX-License-Identifier: GPL-2.0
2 #define _GNU_SOURCE
3 #include <test_progs.h>
4 #include <sys/stat.h>
5 #include <linux/sched.h>
6 #include <sys/syscall.h>
7
8 #define MAX_PATH_LEN 128
9 #define MAX_FILES 7
10
11 #include "test_d_path.skel.h"
12 #include "test_d_path_check_rdonly_mem.skel.h"
13 #include "test_d_path_check_types.skel.h"
14
15 /* sys_close_range is not around for long time, so let's
16 * make sure we can call it on systems with older glibc
17 */
18 #ifndef __NR_close_range
19 #ifdef __alpha__
20 #define __NR_close_range 546
21 #else
22 #define __NR_close_range 436
23 #endif
24 #endif
25
26 static int duration;
27
28 static struct {
29 __u32 cnt;
30 char paths[MAX_FILES][MAX_PATH_LEN];
31 } src;
32
33 static int set_pathname(int fd, pid_t pid)
34 {
35 char buf[MAX_PATH_LEN];
36
37 snprintf(buf, MAX_PATH_LEN, "/proc/%d/fd/%d", pid, fd);
38 return readlink(buf, src.paths[src.cnt++], MAX_PATH_LEN);
39 }
40
41 static int trigger_fstat_events(pid_t pid)
42 {
43 int sockfd = -1, procfd = -1, devfd = -1;
44 int localfd = -1, indicatorfd = -1;
45 int pipefd[2] = { -1, -1 };
46 struct stat fileStat;
47 int ret = -1;
48
49 /* unmountable pseudo-filesystems */
50 if (CHECK(pipe(pipefd) < 0, "trigger", "pipe failed\n"))
51 return ret;
52 /* unmountable pseudo-filesystems */
53 sockfd = socket(AF_INET, SOCK_STREAM, 0);
54 if (CHECK(sockfd < 0, "trigger", "socket failed\n"))
55 goto out_close;
56 /* mountable pseudo-filesystems */
57 procfd = open("/proc/self/comm", O_RDONLY);
58 if (CHECK(procfd < 0, "trigger", "open /proc/self/comm failed\n"))
59 goto out_close;
60 devfd = open("/dev/urandom", O_RDONLY);
61 if (CHECK(devfd < 0, "trigger", "open /dev/urandom failed\n"))
62 goto out_close;
63 localfd = open("/tmp/d_path_loadgen.txt", O_CREAT | O_RDONLY, 0644);
64 if (CHECK(localfd < 0, "trigger", "open /tmp/d_path_loadgen.txt failed\n"))
65 goto out_close;
66 /* bpf_d_path will return path with (deleted) */
67 remove("/tmp/d_path_loadgen.txt");
68 indicatorfd = open("/tmp/", O_PATH);
69 if (CHECK(indicatorfd < 0, "trigger", "open /tmp/ failed\n"))
70 goto out_close;
71
72 ret = set_pathname(pipefd[0], pid);
73 if (CHECK(ret < 0, "trigger", "set_pathname failed for pipe[0]\n"))
74 goto out_close;
75 ret = set_pathname(pipefd[1], pid);
76 if (CHECK(ret < 0, "trigger", "set_pathname failed for pipe[1]\n"))
77 goto out_close;
78 ret = set_pathname(sockfd, pid);
79 if (CHECK(ret < 0, "trigger", "set_pathname failed for socket\n"))
80 goto out_close;
81 ret = set_pathname(procfd, pid);
82 if (CHECK(ret < 0, "trigger", "set_pathname failed for proc\n"))
83 goto out_close;
84 ret = set_pathname(devfd, pid);
85 if (CHECK(ret < 0, "trigger", "set_pathname failed for dev\n"))
86 goto out_close;
87 ret = set_pathname(localfd, pid);
88 if (CHECK(ret < 0, "trigger", "set_pathname failed for file\n"))
89 goto out_close;
90 ret = set_pathname(indicatorfd, pid);
91 if (CHECK(ret < 0, "trigger", "set_pathname failed for dir\n"))
92 goto out_close;
93
94 /* triggers vfs_getattr */
95 fstat(pipefd[0], &fileStat);
96 fstat(pipefd[1], &fileStat);
97 fstat(sockfd, &fileStat);
98 fstat(procfd, &fileStat);
99 fstat(devfd, &fileStat);
100 fstat(localfd, &fileStat);
101 fstat(indicatorfd, &fileStat);
102
103 out_close:
104 /* sys_close no longer triggers filp_close, but we can
105 * call sys_close_range instead which still does
106 */
107 #define close(fd) syscall(__NR_close_range, fd, fd, 0)
108
109 close(pipefd[0]);
110 close(pipefd[1]);
111 close(sockfd);
112 close(procfd);
113 close(devfd);
114 close(localfd);
115 close(indicatorfd);
116
117 #undef close
118 return ret;
119 }
120
121 static void test_d_path_basic(void)
122 {
123 struct test_d_path__bss *bss;
124 struct test_d_path *skel;
125 int err;
126
127 skel = test_d_path__open_and_load();
128 if (CHECK(!skel, "setup", "d_path skeleton failed\n"))
129 goto cleanup;
130
131 err = test_d_path__attach(skel);
132 if (CHECK(err, "setup", "attach failed: %d\n", err))
133 goto cleanup;
134
135 bss = skel->bss;
136 bss->my_pid = getpid();
137
138 err = trigger_fstat_events(bss->my_pid);
139 if (err < 0)
140 goto cleanup;
141
142 if (CHECK(!bss->called_stat,
143 "stat",
144 "trampoline for security_inode_getattr was not called\n"))
145 goto cleanup;
146
147 if (CHECK(!bss->called_close,
148 "close",
149 "trampoline for filp_close was not called\n"))
150 goto cleanup;
151
152 for (int i = 0; i < MAX_FILES; i++) {
153 CHECK(strncmp(src.paths[i], bss->paths_stat[i], MAX_PATH_LEN),
154 "check",
155 "failed to get stat path[%d]: %s vs %s\n",
156 i, src.paths[i], bss->paths_stat[i]);
157 CHECK(strncmp(src.paths[i], bss->paths_close[i], MAX_PATH_LEN),
158 "check",
159 "failed to get close path[%d]: %s vs %s\n",
160 i, src.paths[i], bss->paths_close[i]);
161 /* The d_path helper returns size plus NUL char, hence + 1 */
162 CHECK(bss->rets_stat[i] != strlen(bss->paths_stat[i]) + 1,
163 "check",
164 "failed to match stat return [%d]: %d vs %zd [%s]\n",
165 i, bss->rets_stat[i], strlen(bss->paths_stat[i]) + 1,
166 bss->paths_stat[i]);
167 CHECK(bss->rets_close[i] != strlen(bss->paths_stat[i]) + 1,
168 "check",
169 "failed to match stat return [%d]: %d vs %zd [%s]\n",
170 i, bss->rets_close[i], strlen(bss->paths_close[i]) + 1,
171 bss->paths_stat[i]);
172 }
173
174 cleanup:
175 test_d_path__destroy(skel);
176 }
177
178 static void test_d_path_check_rdonly_mem(void)
179 {
180 struct test_d_path_check_rdonly_mem *skel;
181
182 skel = test_d_path_check_rdonly_mem__open_and_load();
183 ASSERT_ERR_PTR(skel, "unexpected_load_overwriting_rdonly_mem");
184
185 test_d_path_check_rdonly_mem__destroy(skel);
186 }
187
188 static void test_d_path_check_types(void)
189 {
190 struct test_d_path_check_types *skel;
191
192 skel = test_d_path_check_types__open_and_load();
193 ASSERT_ERR_PTR(skel, "unexpected_load_passing_wrong_type");
194
195 test_d_path_check_types__destroy(skel);
196 }
197
198 void test_d_path(void)
199 {
200 if (test__start_subtest("basic"))
201 test_d_path_basic();
202
203 if (test__start_subtest("check_rdonly_mem"))
204 test_d_path_check_rdonly_mem();
205
206 if (test__start_subtest("check_alloc_mem"))
207 test_d_path_check_types();
208 }
209
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