1 /* SPDX-License-Identifier: MIT */
2 /*
3 * Description: test io_uring linkat handling
4 */
5 #include <fcntl.h>
6 #include <stdio.h>
7 #include <string.h>
8 #include <sys/stat.h>
9 #include <sys/types.h>
10 #include <unistd.h>
11
12 #include "liburing.h"
13 #include "helpers.h"
14
do_linkat(struct io_uring * ring,int olddirfd,const char * oldname,const char * newname,int flags)15 static int do_linkat(struct io_uring *ring, int olddirfd, const char *oldname,
16 const char *newname, int flags)
17 {
18 struct io_uring_sqe *sqe;
19 struct io_uring_cqe *cqe;
20 int ret;
21
22 sqe = io_uring_get_sqe(ring);
23 if (!sqe) {
24 fprintf(stderr, "sqe get failed\n");
25 return 1;
26 }
27 io_uring_prep_linkat(sqe, olddirfd, oldname, AT_FDCWD, newname, flags);
28
29 ret = io_uring_submit(ring);
30 if (ret != 1) {
31 fprintf(stderr, "submit failed: %d\n", ret);
32 return 1;
33 }
34
35 ret = io_uring_wait_cqes(ring, &cqe, 1, 0, 0);
36 if (ret) {
37 fprintf(stderr, "wait_cqe failed: %d\n", ret);
38 return 1;
39 }
40 ret = cqe->res;
41 io_uring_cqe_seen(ring, cqe);
42 return ret;
43 }
44
files_linked_ok(const char * fn1,const char * fn2)45 static int files_linked_ok(const char* fn1, const char *fn2)
46 {
47 struct stat s1, s2;
48
49 if (stat(fn1, &s1)) {
50 fprintf(stderr, "stat(%s): %s\n", fn1, strerror(errno));
51 return 0;
52 }
53 if (stat(fn2, &s2)) {
54 fprintf(stderr, "stat(%s): %s\n", fn2, strerror(errno));
55 return 0;
56 }
57 if (s1.st_dev != s2.st_dev || s1.st_ino != s2.st_ino) {
58 fprintf(stderr, "linked files have different device / inode numbers\n");
59 return 0;
60 }
61 if (s1.st_nlink != 2 || s2.st_nlink != 2) {
62 fprintf(stderr, "linked files have unexpected links count\n");
63 return 0;
64 }
65 return 1;
66 }
67
main(int argc,char * argv[])68 int main(int argc, char *argv[])
69 {
70 static const char target[] = "io_uring-linkat-test-target";
71 static const char emptyname[] = "io_uring-linkat-test-empty";
72 static const char linkname[] = "io_uring-linkat-test-link";
73 static const char symlinkname[] = "io_uring-linkat-test-symlink";
74 struct io_uring ring;
75 int ret, fd, exit_status = T_EXIT_FAIL;
76
77 if (argc > 1)
78 return T_EXIT_SKIP;
79
80 ret = io_uring_queue_init(8, &ring, 0);
81 if (ret) {
82 fprintf(stderr, "queue init failed: %d\n", ret);
83 return ret;
84 }
85
86 ret = fd = open(target, O_CREAT | O_RDWR | O_EXCL, 0600);
87 if (ret < 0) {
88 perror("open");
89 goto out;
90 }
91 if (write(fd, "linktest", 8) != 8) {
92 close(fd);
93 goto out;
94 }
95 if(geteuid()) {
96 fprintf(stdout, "not root, skipping AT_EMPTY_PATH test\n");
97 } else {
98 ret = do_linkat(&ring, fd, "", emptyname, AT_EMPTY_PATH);
99 if (ret < 0) {
100 if (ret == -EBADF || ret == -EINVAL) {
101 fprintf(stdout, "linkat not supported, skipping\n");
102 exit_status = T_EXIT_SKIP;
103 goto out;
104 }
105 fprintf(stderr, "linkat: %s\n", strerror(-ret));
106 goto out;
107 } else if (ret) {
108 goto out;
109 }
110 if (!files_linked_ok(emptyname, target))
111 goto out;
112 unlinkat(AT_FDCWD, emptyname, 0);
113 }
114 close(fd);
115
116 ret = symlink(target, symlinkname);
117 if (ret < 0) {
118 perror("open");
119 goto out;
120 }
121
122 ret = do_linkat(&ring, AT_FDCWD, target, linkname, 0);
123 if (ret < 0) {
124 if (ret == -EBADF || ret == -EINVAL) {
125 fprintf(stdout, "linkat not supported, skipping\n");
126 exit_status = T_EXIT_SKIP;
127 goto out;
128 }
129 fprintf(stderr, "linkat: %s\n", strerror(-ret));
130 goto out;
131 } else if (ret) {
132 goto out;
133 }
134
135 if (!files_linked_ok(linkname, target))
136 goto out;
137
138 unlinkat(AT_FDCWD, linkname, 0);
139
140 ret = do_linkat(&ring, AT_FDCWD, symlinkname, linkname, AT_SYMLINK_FOLLOW);
141 if (ret < 0) {
142 fprintf(stderr, "linkat: %s\n", strerror(-ret));
143 goto out;
144 } else if (ret) {
145 goto out;
146 }
147
148 if (!files_linked_ok(symlinkname, target))
149 goto out;
150
151 ret = do_linkat(&ring, AT_FDCWD, target, linkname, 0);
152 if (ret != -EEXIST) {
153 fprintf(stderr, "test_linkat linkname already exists failed: %d\n", ret);
154 goto out;
155 }
156
157 ret = do_linkat(&ring, AT_FDCWD, target, "surely/this/does/not/exist", 0);
158 if (ret != -ENOENT) {
159 fprintf(stderr, "test_linkat no parent failed: %d\n", ret);
160 goto out;
161 }
162 exit_status = T_EXIT_PASS;
163 out:
164 unlinkat(AT_FDCWD, symlinkname, 0);
165 unlinkat(AT_FDCWD, linkname, 0);
166 unlinkat(AT_FDCWD, emptyname, 0);
167 unlinkat(AT_FDCWD, target, 0);
168 io_uring_queue_exit(&ring);
169 return exit_status;
170 }
171