diff options
Diffstat (limited to 'contrib/file/compress.c')
| -rw-r--r-- | contrib/file/compress.c | 59 |
1 files changed, 49 insertions, 10 deletions
diff --git a/contrib/file/compress.c b/contrib/file/compress.c index a33c7e9..5989eb2 100644 --- a/contrib/file/compress.c +++ b/contrib/file/compress.c @@ -42,6 +42,7 @@ #include <string.h> #include <errno.h> #include <sys/types.h> +#include <sys/ioctl.h> #ifdef HAVE_SYS_WAIT_H #include <sys/wait.h> #endif @@ -50,10 +51,9 @@ #endif #ifndef lint -FILE_RCSID("@(#)$Id: compress.c,v 1.42 2005/03/06 05:58:22 christos Exp $") +FILE_RCSID("@(#)$Id: compress.c,v 1.45 2006/10/31 19:37:17 christos Exp $") #endif - private struct { const char *magic; size_t maglen; @@ -76,9 +76,10 @@ private struct { private int ncompr = sizeof(compr) / sizeof(compr[0]); +#define NODATA ((size_t)~0) + private ssize_t swrite(int, const void *, size_t); -private ssize_t sread(int, void *, size_t); private size_t uncompressbuf(struct magic_set *, int, size_t, const unsigned char *, unsigned char **, size_t); #ifdef HAVE_LIBZ @@ -102,7 +103,7 @@ file_zmagic(struct magic_set *ms, int fd, const unsigned char *buf, continue; if (memcmp(buf, compr[i].magic, compr[i].maglen) == 0 && (nsz = uncompressbuf(ms, fd, i, buf, &newbuf, - nbytes)) != 0) { + nbytes)) != NODATA) { ms->flags &= ~MAGIC_COMPRESS; rv = -1; if (file_buffer(ms, -1, newbuf, nsz) == -1) @@ -152,14 +153,52 @@ swrite(int fd, const void *buf, size_t n) /* * `safe' read for sockets and pipes. */ -private ssize_t +protected ssize_t sread(int fd, void *buf, size_t n) { int rv; +#ifdef FIONREAD + int t = 0; +#endif size_t rn = n; + if (fd == STDIN_FILENO) + goto nocheck; + +#ifdef FIONREAD + if ((ioctl(fd, FIONREAD, &t) < 0) || (t == 0)) { +#ifdef FD_ZERO + for (;;) { + fd_set check; + struct timeval tout = {0, 100 * 1000}; + + FD_ZERO(&check); + FD_SET(fd, &check); + + /* + * Avoid soft deadlock: do not read if there + * is nothing to read from sockets and pipes. + */ + if (select(fd + 1, &check, NULL, NULL, &tout) <= 0) { + if (errno == EINTR || errno == EAGAIN) + continue; + return 0; + } + break; + } +#endif + (void)ioctl(fd, FIONREAD, &t); + } + + if (t > 0 && (size_t)t < n) { + n = t; + rn = n; + } +#endif + +nocheck: do - switch (rv = read(fd, buf, n)) { + switch ((rv = read(fd, buf, n))) { case -1: if (errno == EINTR) continue; @@ -305,7 +344,7 @@ uncompressgzipped(struct magic_set *ms, const unsigned char *old, inflateEnd(&z); /* let's keep the nul-terminate tradition */ - (*newch)[n++] = '\0'; + (*newch)[n] = '\0'; return n; } @@ -327,7 +366,7 @@ uncompressbuf(struct magic_set *ms, int fd, size_t method, if ((fd != -1 && pipe(fdin) == -1) || pipe(fdout) == -1) { file_error(ms, errno, "cannot create pipe"); - return 0; + return NODATA; } switch (fork()) { case 0: /* child */ @@ -360,7 +399,7 @@ uncompressbuf(struct magic_set *ms, int fd, size_t method, /*NOTREACHED*/ case -1: file_error(ms, errno, "could not fork"); - return 0; + return NODATA; default: /* parent */ (void) close(fdout[1]); @@ -420,7 +459,7 @@ uncompressbuf(struct magic_set *ms, int fd, size_t method, n = r; } /* NUL terminate, as every buffer is handled here. */ - (*newch)[n++] = '\0'; + (*newch)[n] = '\0'; err: if (fdin[1] != -1) (void) close(fdin[1]); |
