[LTP] [RFC PATCH v2 1/7] API: Add safe openat, printfat, readat and unlinkat

[Li Wang]

Hi Richard,

Richard Palethorpe <rpalethorpe@suse.com> wrote:

...
> +char *tst_decode_fd(int fd);
> +
> +int safe_openat(const char *file, const int lineno,
> +               int dirfd, const char *path, int oflags, ...);
> +
> +ssize_t safe_file_readat(const char *file, const int lineno,
> +                        int dirfd, const char *path, char *buf, size_t
> nbyte);
> +
> +int tst_file_vprintfat(int dirfd, const char *path, const char *fmt,
> va_list va);
> +int tst_file_printfat(int dirfd, const char *path, const char *fmt, ...)
> +                       __attribute__ ((format (printf, 3, 4)));
> +
> +int safe_file_vprintfat(const char *file, const int lineno,
> +                       int dirfd, const char *path,
> +                       const char *fmt, va_list va);
> +
> +int safe_file_printfat(const char *file, const int lineno,
> +                      int dirfd, const char *path, const char *fmt, ...)
> +                       __attribute__ ((format (printf, 5, 6)));
> +
> +int safe_unlinkat(const char *file, const int lineno,
> +                 int dirfd, const char *path, int flags);
>

I guess these prototypes should be moved to "safe_file_ops_fn.h"?
(It seems the author did that on purpose to separate macros and function
declaration)


--- /dev/null
> +++ b/lib/tst_safe_file_ops.c
>

Then we can achieve all the above functions in "lib/safe_file_ops.c"
without creating a new file.



> @@ -0,0 +1,171 @@
> +#define _GNU_SOURCE
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include "lapi/fcntl.h"
> +
> +#define TST_NO_DEFAULT_MAIN
> +#include "tst_test.h"
> +
> +char fd_path[PATH_MAX];
> +
> +char *tst_decode_fd(int fd)
> +{
> +       ssize_t ret;
> +       char proc_path[32];
> +
> +       if (fd < 0)
> +               return "!";
> +
> +       sprintf(proc_path, "/proc/self/fd/%d", fd);
> +       ret = readlink(proc_path, fd_path, sizeof(fd_path));
> +
> +       if (ret < 0)
> +               return "?";
> +
> +       fd_path[ret] = '\0';
> +
> +       return fd_path;
> +}
> +
> +int safe_openat(const char *file, const int lineno,
> +               int dirfd, const char *path, int oflags, ...)
> +{
> +       va_list ap;
> +       int fd;
> +       mode_t mode;
> +
> +       va_start(ap, oflags);
> +       mode = va_arg(ap, int);
> +       va_end(ap);
> +
> +       fd = openat(dirfd, path, oflags, mode);
> +       if (fd > -1)
> +               return fd;
> +
> +       tst_brk_(file, lineno, TBROK | TERRNO,
> +                "openat(%d<%s>, '%s', %o, %o)",
> +                dirfd, tst_decode_fd(dirfd), path, oflags, mode);
> +
> +       return fd;
> +}
> +
> +ssize_t safe_file_readat(const char *file, const int lineno,
> +                        int dirfd, const char *path, char *buf, size_t
> nbyte)
> +{
> +       int fd = safe_openat(file, lineno, dirfd, path, O_RDONLY);
> +       ssize_t rval;
> +
> +       if (fd < 0)
> +               return -1;
> +
> +       rval = safe_read(file, lineno, NULL, 0, fd, buf, nbyte - 1);
> +       if (rval < 0)
> +               return -1;
> +
> +       close(fd);
> +       buf[rval] = '\0';
> +
> +       if (rval >= (ssize_t)nbyte - 1) {
> +               tst_brk_(file, lineno, TBROK,
> +                       "Buffer length %zu too small to read %d<%s>/%s",
> +                       nbyte, dirfd, tst_decode_fd(dirfd), path);
> +       }
> +
> +       return rval;
> +}
> +
> +int tst_file_vprintfat(int dirfd, const char *path, const char *fmt,
> va_list va)
> +{
> +       int fd = openat(dirfd, path, O_WRONLY);
> +
> +       if (fd < 0)
> +               return -1;
> +
> +       TEST(vdprintf(fd, fmt, va));
> +       close(fd);
> +
> +       if (TST_RET < 0) {
> +               errno = TST_ERR;
> +               return -2;
> +       }
> +
> +       return TST_RET;
> +}
> +
> +int tst_file_printfat(int dirfd, const char *path, const char *fmt, ...)
> +{
> +       va_list va;
> +       int rval;
> +
> +       va_start(va, fmt);
> +       rval = tst_file_vprintfat(dirfd, path, fmt, va);
> +       va_end(va);
> +
> +       return rval;
> +}
> +
> +int safe_file_vprintfat(const char *file, const int lineno,
> +                       int dirfd, const char *path,
> +                       const char *fmt, va_list va)
> +{
> +       char buf[16];
> +       va_list vac;
> +       int rval;
> +
> +       va_copy(vac, va);
> +
> +       TEST(tst_file_vprintfat(dirfd, path, fmt, va));
> +
> +       if (TST_RET == -2) {
> +               rval = vsnprintf(buf, sizeof(buf), fmt, vac);
> +               va_end(vac);
> +
> +               if (rval >= (ssize_t)sizeof(buf))
> +                       strcpy(buf + sizeof(buf) - 5, "...");
> +
> +               tst_brk_(file, lineno, TBROK | TTERRNO,
> +                        "vdprintf(%d<%s>, '%s', '%s'<%s>)",
> +                        dirfd, tst_decode_fd(dirfd), path, fmt,
> +                        rval > 0 ? buf : "???");
> +               return -1;
> +       }
> +
> +       va_end(vac);
> +
> +       if (TST_RET == -1) {
> +               tst_brk_(file, lineno, TBROK | TTERRNO,
> +                       "openat(%d<%s>, '%s', O_WRONLY)",
> +                       dirfd, tst_decode_fd(dirfd), path);
> +       }
> +
> +       return TST_RET;
> +}
> +
> +int safe_file_printfat(const char *file, const int lineno,
> +                      int dirfd, const char *path,
> +                      const char *fmt, ...)
> +{
> +       va_list va;
> +       int rval;
> +
> +       va_start(va, fmt);
> +       rval = safe_file_vprintfat(file, lineno, dirfd, path, fmt, va);
> +       va_end(va);
> +
> +       return rval;
> +}
> +
> +int safe_unlinkat(const char *file, const int lineno,
> +                 int dirfd, const char *path, int flags)
> +{
> +       int rval = unlinkat(dirfd, path, flags);
> +
> +       if (rval > -1)
> +               return rval;
> +
> +       tst_brk_(file, lineno, TBROK | TERRNO,
> +                "unlinkat(%d<%s>, '%s', %s)", dirfd,
> tst_decode_fd(dirfd), path,
> +                flags == AT_REMOVEDIR ? "AT_REMOVEDIR" : (flags ? "?" :
> "0"));
> +
> +       return rval;
> +}
> --
> 2.30.0
>
>

-- 
Regards,
Li Wang
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