diff options
Diffstat (limited to 'extension')
| -rw-r--r-- | extension/ChangeLog | 8 | ||||
| -rw-r--r-- | extension/filefuncs.c | 73 | ||||
| -rw-r--r-- | extension/fork.c | 20 |
3 files changed, 88 insertions, 13 deletions
diff --git a/extension/ChangeLog b/extension/ChangeLog index 287ce309..994b3c92 100644 --- a/extension/ChangeLog +++ b/extension/ChangeLog @@ -1,3 +1,11 @@ +2012-04-07 Andrew J. Schorr <aschorr@telemetry-investments.com> + + * filefuncs.c: Remove unnecessary #include <sys/sysmacros.h>. + (read_symlink): New function to read symbolic links more robustly. + (do_stat): Use read_symlink instead of readlink. + * fork.c (do_wait): new function. + (dlload): Call make_builtin to add "wait" function. + 2012-04-02 Andrew J. Schorr <aschorr@telemetry-investments.com> * fork.c (do_fork): Test whether PROCINFO_node exists before updating diff --git a/extension/filefuncs.c b/extension/filefuncs.c index 63010c35..6d46c5e5 100644 --- a/extension/filefuncs.c +++ b/extension/filefuncs.c @@ -29,8 +29,6 @@ #include "awk.h" -#include <sys/sysmacros.h> - int plugin_is_GPL_compatible; /* do_chdir --- provide dynamically loaded chdir() builtin for gawk */ @@ -157,6 +155,60 @@ format_mode(unsigned long fmode) return outbuf; } +/* read_symlink -- read a symbolic link into an allocated buffer. + This is based on xreadlink; the basic problem is that lstat cannot be relied + upon to return the proper size for a symbolic link. This happens, + for example, on linux in the /proc filesystem, where the symbolic link + sizes are often 0. */ + +#ifndef SIZE_MAX +# define SIZE_MAX ((size_t) -1) +#endif +#ifndef SSIZE_MAX +# define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2)) +#endif + +#define MAXSIZE (SIZE_MAX < SSIZE_MAX ? SIZE_MAX : SSIZE_MAX) + +static char * +read_symlink(const char *fname, size_t bufsize, ssize_t *linksize) +{ + if (bufsize) + bufsize += 2; + else + bufsize = BUFSIZ*2; + /* Make sure that bufsize >= 2 and within range */ + if ((bufsize > MAXSIZE) || (bufsize < 2)) + bufsize = MAXSIZE; + while (1) { + char *buf; + + emalloc(buf, char *, bufsize, "read_symlink"); + if ((*linksize = readlink(fname, buf, bufsize)) < 0) { + /* On AIX 5L v5.3 and HP-UX 11i v2 04/09, readlink + returns -1 with errno == ERANGE if the buffer is + too small. */ + if (errno != ERANGE) { + free(buf); + return NULL; + } + } + /* N.B. This test is safe because bufsize must be >= 2 */ + else if ((size_t)*linksize <= bufsize-2) { + buf[*linksize] = '\0'; + return buf; + } + free(buf); + if (bufsize <= MAXSIZE/2) + bufsize *= 2; + else if (bufsize < MAXSIZE) + bufsize = MAXSIZE; + else + return NULL; + } + return NULL; +} + /* do_stat --- provide a stat() function for gawk */ static NODE * @@ -265,22 +317,17 @@ do_stat(int nargs) /* for symbolic links, add a linkval field */ if (S_ISLNK(sbuf.st_mode)) { char *buf; - int linksize; - - emalloc(buf, char *, sbuf.st_size + 2, "do_stat"); - if (((linksize = readlink(file->stptr, buf, - sbuf.st_size + 2)) >= 0) && - (linksize <= sbuf.st_size)) { - /* - * set the linkval field only if we are able to - * retrieve the entire link value successfully. - */ - buf[linksize] = '\0'; + ssize_t linksize; + if ((buf = read_symlink(file->stptr, sbuf.st_size, + &linksize)) != NULL) { aptr = assoc_lookup(array, tmp = make_string("linkval", 7)); *aptr = make_str_node(buf, linksize, ALREADY_MALLOCED); unref(tmp); } + else + warning(_("unable to read symbolic link `%s'"), + file->stptr); } /* add a type field */ diff --git a/extension/fork.c b/extension/fork.c index 7d6ab362..5a6e96d5 100644 --- a/extension/fork.c +++ b/extension/fork.c @@ -93,6 +93,25 @@ do_waitpid(int nargs) return make_number((AWKNUM) ret); } + +/* do_wait --- provide dynamically loaded wait() builtin for gawk */ + +static NODE * +do_wait(int nargs) +{ + int ret; + + if (do_lint && nargs > 0) + lintwarn("wait: called with too many arguments"); + + ret = wait(NULL); + if (ret < 0) + update_ERRNO_int(errno); + + /* Set the return value */ + return make_number((AWKNUM) ret); +} + /* dlload --- load new builtins in this library */ NODE * @@ -102,5 +121,6 @@ void *dl; { make_builtin("fork", do_fork, 0); make_builtin("waitpid", do_waitpid, 1); + make_builtin("wait", do_wait, 0); return make_number((AWKNUM) 0); } |