From 28355a36da6ad4d1b55ba9bb146fb0b6586e7edb Mon Sep 17 00:00:00 2001 From: Eric Andersen Date: Mon, 7 May 2001 17:48:28 +0000 Subject: [PATCH] Per some comments from Lars Kellogg-Stedman , make xreadlink() return NULL on failure, and make sure everyone uses the interface correctly. -Erik --- applets/busybox.c | 5 +---- archival/tar.c | 2 ++ busybox.c | 5 +---- libbb/xreadlink.c | 9 ++++++--- miscutils/readlink.c | 2 ++ readlink.c | 2 ++ tar.c | 2 ++ 7 files changed, 16 insertions(+), 11 deletions(-) diff --git a/applets/busybox.c b/applets/busybox.c index badd53d79..41b6069ed 100644 --- a/applets/busybox.c +++ b/applets/busybox.c @@ -37,10 +37,7 @@ typedef int (*__link_f)(const char *, const char *); */ static char *busybox_fullpath() { - char proc[256]; - - sprintf(proc, "/proc/%d/exe", getpid()); - return xreadlink(proc); + return xreadlink("/proc/self/exe"); } /* create (sym)links for each applet */ diff --git a/archival/tar.c b/archival/tar.c index eb085c770..135bfd186 100644 --- a/archival/tar.c +++ b/archival/tar.c @@ -922,6 +922,8 @@ writeTarHeader(struct TarBallInfo *tbInfo, const char *header_name, strncpy(header.linkname, tbInfo->hlInfo->name, sizeof(header.linkname)); } else if (S_ISLNK(statbuf->st_mode)) { char *lpath = xreadlink(real_name); + if (!lpath) /* Already printed err msg inside xreadlink() */ + return ( FALSE); header.typeflag = SYMTYPE; strncpy(header.linkname, lpath, sizeof(header.linkname)); free(lpath); diff --git a/busybox.c b/busybox.c index badd53d79..41b6069ed 100644 --- a/busybox.c +++ b/busybox.c @@ -37,10 +37,7 @@ typedef int (*__link_f)(const char *, const char *); */ static char *busybox_fullpath() { - char proc[256]; - - sprintf(proc, "/proc/%d/exe", getpid()); - return xreadlink(proc); + return xreadlink("/proc/self/exe"); } /* create (sym)links for each applet */ diff --git a/libbb/xreadlink.c b/libbb/xreadlink.c index 66f63b883..932e487a5 100644 --- a/libbb/xreadlink.c +++ b/libbb/xreadlink.c @@ -1,5 +1,6 @@ /* - * xreadlink.c - safe implementation of readlink + * xreadlink.c - safe implementation of readlink. + * Returns a NULL on failure... */ #include @@ -22,8 +23,10 @@ extern char *xreadlink(const char *path) do { buf = xrealloc(buf, bufsize += GROWBY); readsize = readlink(path, buf, bufsize); /* 1st try */ - if (readsize == -1) - perror_msg("%s:%s", applet_name, path); + if (readsize == -1) { + perror_msg("%s:%s", applet_name, path); + return NULL; + } } while (bufsize < readsize + 1); diff --git a/miscutils/readlink.c b/miscutils/readlink.c index 226649544..c46ebd108 100644 --- a/miscutils/readlink.c +++ b/miscutils/readlink.c @@ -37,6 +37,8 @@ int readlink_main(int argc, char **argv) show_usage(); buf = xreadlink(argv[1]); + if (!buf) + return EXIT_FAILURE; puts(buf); #ifdef BB_FEATURE_CLEAN_UP free(buf); diff --git a/readlink.c b/readlink.c index 226649544..c46ebd108 100644 --- a/readlink.c +++ b/readlink.c @@ -37,6 +37,8 @@ int readlink_main(int argc, char **argv) show_usage(); buf = xreadlink(argv[1]); + if (!buf) + return EXIT_FAILURE; puts(buf); #ifdef BB_FEATURE_CLEAN_UP free(buf); diff --git a/tar.c b/tar.c index eb085c770..135bfd186 100644 --- a/tar.c +++ b/tar.c @@ -922,6 +922,8 @@ writeTarHeader(struct TarBallInfo *tbInfo, const char *header_name, strncpy(header.linkname, tbInfo->hlInfo->name, sizeof(header.linkname)); } else if (S_ISLNK(statbuf->st_mode)) { char *lpath = xreadlink(real_name); + if (!lpath) /* Already printed err msg inside xreadlink() */ + return ( FALSE); header.typeflag = SYMTYPE; strncpy(header.linkname, lpath, sizeof(header.linkname)); free(lpath); -- 2.25.1