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#include "kernel/param.h"
#include "kernel/types.h"
#include "kernel/stat.h"
#include "kernel/riscv.h"
#include "kernel/fcntl.h"
#include "kernel/spinlock.h"
#include "kernel/sleeplock.h"
#include "kernel/fs.h"
#include "kernel/file.h"
#include "user/user.h"
#define fail(msg) do {printf("FAILURE: " msg "\n"); failed = 1; goto done;} while (0);
static int failed = 0;
static void testsymlink(void);
static void concur(void);
static void cleanup(void);
int
main(int argc, char *argv[])
{
cleanup();
testsymlink();
concur();
exit(failed);
}
static void
cleanup(void)
{
unlink("/testsymlink/a");
unlink("/testsymlink/b");
unlink("/testsymlink/c");
unlink("/testsymlink/1");
unlink("/testsymlink/2");
unlink("/testsymlink/3");
unlink("/testsymlink/4");
unlink("/testsymlink/z");
unlink("/testsymlink/y");
unlink("/testsymlink");
}
// stat a symbolic link using O_NOFOLLOW
static int
stat_slink(char *pn, struct stat *st)
{
int fd = open(pn, O_RDONLY | O_NOFOLLOW);
if(fd < 0)
return -1;
if(fstat(fd, st) != 0)
return -1;
return 0;
}
static void
testsymlink(void)
{
int r, fd1 = -1, fd2 = -1;
char buf[4] = {'a', 'b', 'c', 'd'};
char c = 0, c2 = 0;
struct stat st;
printf("Start: test symlinks\n");
mkdir("/testsymlink");
fd1 = open("/testsymlink/a", O_CREATE | O_RDWR);
if(fd1 < 0) fail("failed to open a");
r = symlink("/testsymlink/a", "/testsymlink/b");
if(r < 0)
fail("symlink b -> a failed");
if(write(fd1, buf, sizeof(buf)) != 4)
fail("failed to write to a");
if (stat_slink("/testsymlink/b", &st) != 0)
fail("failed to stat b");
if(st.type != T_SYMLINK)
fail("b isn't a symlink");
fd2 = open("/testsymlink/b", O_RDWR);
if(fd2 < 0)
fail("failed to open b");
read(fd2, &c, 1);
if (c != 'a')
fail("failed to read bytes from b");
unlink("/testsymlink/a");
if(open("/testsymlink/b", O_RDWR) >= 0)
fail("Should not be able to open b after deleting a");
r = symlink("/testsymlink/b", "/testsymlink/a");
if(r < 0)
fail("symlink a -> b failed");
r = open("/testsymlink/b", O_RDWR);
if(r >= 0)
fail("Should not be able to open b (cycle b->a->b->..)\n");
r = symlink("/testsymlink/nonexistent", "/testsymlink/c");
if(r != 0)
fail("Symlinking to nonexistent file should succeed\n");
r = symlink("/testsymlink/2", "/testsymlink/1");
if(r) fail("Failed to link 1->2");
r = symlink("/testsymlink/3", "/testsymlink/2");
if(r) fail("Failed to link 2->3");
r = symlink("/testsymlink/4", "/testsymlink/3");
if(r) fail("Failed to link 3->4");
close(fd1);
close(fd2);
fd1 = open("/testsymlink/4", O_CREATE | O_RDWR);
if(fd1<0) fail("Failed to create 4\n");
fd2 = open("/testsymlink/1", O_RDWR);
if(fd2<0) fail("Failed to open 1\n");
c = '#';
r = write(fd2, &c, 1);
if(r!=1) fail("Failed to write to 1\n");
r = read(fd1, &c2, 1);
if(r!=1) fail("Failed to read from 4\n");
if(c!=c2)
fail("Value read from 4 differed from value written to 1\n");
printf("test symlinks: ok\n");
done:
close(fd1);
close(fd2);
}
static void
concur(void)
{
int pid, i;
int fd;
struct stat st;
int nchild = 2;
printf("Start: test concurrent symlinks\n");
fd = open("/testsymlink/z", O_CREATE | O_RDWR);
if(fd < 0) {
printf("FAILED: open failed");
exit(1);
}
close(fd);
for(int j = 0; j < nchild; j++) {
pid = fork();
if(pid < 0){
printf("FAILED: fork failed\n");
exit(1);
}
if(pid == 0) {
int m = 0;
unsigned int x = (pid ? 1 : 97);
for(i = 0; i < 100; i++){
x = x * 1103515245 + 12345;
if((x % 3) == 0) {
symlink("/testsymlink/z", "/testsymlink/y");
if (stat_slink("/testsymlink/y", &st) == 0) {
m++;
if(st.type != T_SYMLINK) {
printf("FAILED: not a symbolic link\n", st.type);
exit(1);
}
}
} else {
unlink("/testsymlink/y");
}
}
exit(0);
}
}
int r;
for(int j = 0; j < nchild; j++) {
wait(&r);
if(r != 0) {
printf("test concurrent symlinks: failed\n");
exit(1);
}
}
printf("test concurrent symlinks: ok\n");
}
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