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
13 static int duration;
14
15 static struct {
16 __u32 cnt;
17 char paths[MAX_FILES][MAX_PATH_LEN];
18 } src;
19
set_pathname(int fd,pid_t pid)20 static int set_pathname(int fd, pid_t pid)
21 {
22 char buf[MAX_PATH_LEN];
23
24 snprintf(buf, MAX_PATH_LEN, "/proc/%d/fd/%d", pid, fd);
25 return readlink(buf, src.paths[src.cnt++], MAX_PATH_LEN);
26 }
27
trigger_fstat_events(pid_t pid)28 static int trigger_fstat_events(pid_t pid)
29 {
30 int sockfd = -1, procfd = -1, devfd = -1;
31 int localfd = -1, indicatorfd = -1;
32 int pipefd[2] = { -1, -1 };
33 struct stat fileStat;
34 int ret = -1;
35
36 /* unmountable pseudo-filesystems */
37 if (CHECK(pipe(pipefd) < 0, "trigger", "pipe failed\n"))
38 return ret;
39 /* unmountable pseudo-filesystems */
40 sockfd = socket(AF_INET, SOCK_STREAM, 0);
41 if (CHECK(sockfd < 0, "trigger", "socket failed\n"))
42 goto out_close;
43 /* mountable pseudo-filesystems */
44 procfd = open("/proc/self/comm", O_RDONLY);
45 if (CHECK(procfd < 0, "trigger", "open /proc/self/comm failed\n"))
46 goto out_close;
47 devfd = open("/dev/urandom", O_RDONLY);
48 if (CHECK(devfd < 0, "trigger", "open /dev/urandom failed\n"))
49 goto out_close;
50 localfd = open("/tmp/d_path_loadgen.txt", O_CREAT | O_RDONLY, 0644);
51 if (CHECK(localfd < 0, "trigger", "open /tmp/d_path_loadgen.txt failed\n"))
52 goto out_close;
53 /* bpf_d_path will return path with (deleted) */
54 remove("/tmp/d_path_loadgen.txt");
55 indicatorfd = open("/tmp/", O_PATH);
56 if (CHECK(indicatorfd < 0, "trigger", "open /tmp/ failed\n"))
57 goto out_close;
58
59 ret = set_pathname(pipefd[0], pid);
60 if (CHECK(ret < 0, "trigger", "set_pathname failed for pipe[0]\n"))
61 goto out_close;
62 ret = set_pathname(pipefd[1], pid);
63 if (CHECK(ret < 0, "trigger", "set_pathname failed for pipe[1]\n"))
64 goto out_close;
65 ret = set_pathname(sockfd, pid);
66 if (CHECK(ret < 0, "trigger", "set_pathname failed for socket\n"))
67 goto out_close;
68 ret = set_pathname(procfd, pid);
69 if (CHECK(ret < 0, "trigger", "set_pathname failed for proc\n"))
70 goto out_close;
71 ret = set_pathname(devfd, pid);
72 if (CHECK(ret < 0, "trigger", "set_pathname failed for dev\n"))
73 goto out_close;
74 ret = set_pathname(localfd, pid);
75 if (CHECK(ret < 0, "trigger", "set_pathname failed for file\n"))
76 goto out_close;
77 ret = set_pathname(indicatorfd, pid);
78 if (CHECK(ret < 0, "trigger", "set_pathname failed for dir\n"))
79 goto out_close;
80
81 /* triggers vfs_getattr */
82 fstat(pipefd[0], &fileStat);
83 fstat(pipefd[1], &fileStat);
84 fstat(sockfd, &fileStat);
85 fstat(procfd, &fileStat);
86 fstat(devfd, &fileStat);
87 fstat(localfd, &fileStat);
88 fstat(indicatorfd, &fileStat);
89
90 out_close:
91 /* triggers filp_close */
92 close(pipefd[0]);
93 close(pipefd[1]);
94 close(sockfd);
95 close(procfd);
96 close(devfd);
97 close(localfd);
98 close(indicatorfd);
99 return ret;
100 }
101
test_d_path(void)102 void test_d_path(void)
103 {
104 struct test_d_path__bss *bss;
105 struct test_d_path *skel;
106 int err;
107
108 skel = test_d_path__open_and_load();
109 if (CHECK(!skel, "setup", "d_path skeleton failed\n"))
110 goto cleanup;
111
112 err = test_d_path__attach(skel);
113 if (CHECK(err, "setup", "attach failed: %d\n", err))
114 goto cleanup;
115
116 bss = skel->bss;
117 bss->my_pid = getpid();
118
119 err = trigger_fstat_events(bss->my_pid);
120 if (err < 0)
121 goto cleanup;
122
123 if (CHECK(!bss->called_stat,
124 "stat",
125 "trampoline for security_inode_getattr was not called\n"))
126 goto cleanup;
127
128 if (CHECK(!bss->called_close,
129 "close",
130 "trampoline for filp_close was not called\n"))
131 goto cleanup;
132
133 for (int i = 0; i < MAX_FILES; i++) {
134 CHECK(strncmp(src.paths[i], bss->paths_stat[i], MAX_PATH_LEN),
135 "check",
136 "failed to get stat path[%d]: %s vs %s\n",
137 i, src.paths[i], bss->paths_stat[i]);
138 CHECK(strncmp(src.paths[i], bss->paths_close[i], MAX_PATH_LEN),
139 "check",
140 "failed to get close path[%d]: %s vs %s\n",
141 i, src.paths[i], bss->paths_close[i]);
142 /* The d_path helper returns size plus NUL char, hence + 1 */
143 CHECK(bss->rets_stat[i] != strlen(bss->paths_stat[i]) + 1,
144 "check",
145 "failed to match stat return [%d]: %d vs %zd [%s]\n",
146 i, bss->rets_stat[i], strlen(bss->paths_stat[i]) + 1,
147 bss->paths_stat[i]);
148 CHECK(bss->rets_close[i] != strlen(bss->paths_stat[i]) + 1,
149 "check",
150 "failed to match stat return [%d]: %d vs %zd [%s]\n",
151 i, bss->rets_close[i], strlen(bss->paths_close[i]) + 1,
152 bss->paths_stat[i]);
153 }
154
155 cleanup:
156 test_d_path__destroy(skel);
157 }
158