PR/492: Don't exit from grandchild (magic_buffer case).

diff --git a/src/compress.c b/src/compress.c
index 01e809a4ab8334816a8c7a203501ceac2511049f..0c590810cdab9d036684995e18dc945387366dd4 100644 (file)
--- a/src/compress.c
+++ b/src/compress.c
@@ -35,7 +35,7 @@
 #include "file.h"
 
 #ifndef lint
-FILE_RCSID("@(#)$File: compress.c,v 1.82 2015/11/09 21:03:51 christos Exp $")
+FILE_RCSID("@(#)$File: compress.c,v 1.83 2015/11/10 17:47:02 christos Exp $")
 #endif
 
 #include "magic.h"
@@ -88,19 +88,28 @@ zlibcmp(const unsigned char *buf)
        unsigned char *s = (unsigned char *)&x;
 
        if ((buf[0] & 0xf) != 8 || (buf[0] & 0x80) != 0)
-               return 1;
+               return 0;
        if (s[0] != 1)  /* endianness test */
                x = buf[0] | (buf[1] << 8);
        else
                x = buf[1] | (buf[0] << 8);
        if (x % 31)
-               return 1;
-       return 0;
+               return 0;
+       return 1;
 }
 #endif
 
+#ifndef DEBUG
+#define gzip_flags "-cdq"
+#define lrzip_flags "-dqo"
+#else
+#define gzip_flags "-cd"
+#define lrzip_flags "-do"
+#endif
+#define lzip_flags gzip_flags
+
 static const char *gzip_args[] = {
-       "gzip", "-cdq", NULL
+       "gzip", gzip_flags, NULL
 };
 static const char *uncompress_args[] = {
        "uncompress", "-c", NULL
@@ -109,13 +118,13 @@ static const char *bzip2_args[] = {
        "bzip2", "-cd", NULL
 };
 static const char *lzip_args[] = {
-       "lzip", "-cdq", NULL
+       "lzip", lzip_flags, NULL
 };
 static const char *xz_args[] = {
        "xz", "-cd", NULL
 };
 static const char *lrzip_args[] = {
-       "lrzip", "-dqo-", NULL
+       "lrzip", lrzip_flags, NULL
 };
 static const char *lz4_args[] = {
        "lz4", "-cd", NULL
@@ -181,18 +190,18 @@ file_zmagic(struct magic_set *ms, int fd, const char *name,
        osigpipe = signal(SIGPIPE, SIG_IGN);
 #endif
        for (i = 0; i < ncompr; i++) {
+               int zm;
                if (nbytes < compr[i].maglen)
                        continue;
 #ifdef ZLIBSUPPORT
                if (compr[i].maglen == 0)
-                       rv = (CAST(int (*)(const unsigned char *),
+                       zm = (CAST(int (*)(const unsigned char *),
                            CCAST(void *, compr[i].magic)))(buf);
                else
 #endif
-                       rv = memcmp(buf, compr[i].magic, compr[i].maglen);
+                       zm = memcmp(buf, compr[i].magic, compr[i].maglen) == 0;
 
-               if (rv == 0 &&
-                   (nsz = uncompressbuf(ms, fd, i, buf, &newbuf,
+               if (zm && (nsz = uncompressbuf(ms, fd, i, buf, &newbuf,
                    nbytes)) != NODATA) {
                        ms->flags &= ~MAGIC_COMPRESS;
                        rv = -1;
@@ -220,6 +229,7 @@ error:
 #endif
        free(newbuf);
        ms->flags |= MAGIC_COMPRESS;
+       DPRINTF("Zmagic returns %d\n", rv);
        return rv;
 }
 #endif
@@ -481,7 +491,12 @@ uncompressbuf(struct magic_set *ms, int fd, size_t method,
        (void)fflush(stdout);
        (void)fflush(stderr);
 
+       fdin[0] = fdout[0] = fdin[1] = fdout[1] = -1;
        if ((fd == -1 && pipe(fdin) == -1) || pipe(fdout) == -1) {
+               if (fdin[0] != -1) {
+                       (void) close(fdin[0]);
+                       (void) close(fdin[1]);
+               }
                file_error(ms, errno, "cannot create pipe");    
                return NODATA;
        }
@@ -503,6 +518,8 @@ uncompressbuf(struct magic_set *ms, int fd, size_t method,
                    }
                    (void) close(fdin[0]);
                    (void) close(fdin[1]);
+                   fdin[0] = -1;
+                   fdin[1] = -1;
                }
 
                (void) close(1);
@@ -512,7 +529,9 @@ uncompressbuf(struct magic_set *ms, int fd, size_t method,
                        exit(1);
                }
                (void) close(fdout[0]);
+               fdout[0] = -1;
                (void) close(fdout[1]);
+               fdout[1] = -1;
 #ifndef DEBUG
                if (compr[method].silent)
                        (void)close(2);
@@ -530,8 +549,10 @@ uncompressbuf(struct magic_set *ms, int fd, size_t method,
 
        default: /* parent */
                (void) close(fdout[1]);
+               fdout[1] = -1;
                if (fd == -1) {
                        (void) close(fdin[0]);
+                       fdin[0] = -1;
                        /* 
                         * fork again, to avoid blocking because both
                         * pipes filled
@@ -539,6 +560,7 @@ uncompressbuf(struct magic_set *ms, int fd, size_t method,
                        switch (fork()) {
                        case 0: /* child */
                                (void)close(fdout[0]);
+                               fdout[0] = -1;
                                if (swrite(fdin[1], old, n) != (ssize_t)n) {
                                        DPRINTF("Write failed (%s)\n",
                                            strerror(errno));
@@ -558,24 +580,21 @@ uncompressbuf(struct magic_set *ms, int fd, size_t method,
                                            strerror(errno));
                                        exit(1);
                                }
-                               exit(WIFEXITED(status) ?
-                                   WEXITSTATUS(status) : 1);
-                               /*NOTREACHED*/
+                               DPRINTF("Grandchild wait return %#x\n", status);
                        }
                        (void) close(fdin[1]);
                        fdin[1] = -1;
                }
 
-               if ((*newch = (unsigned char *) malloc(HOWMANY + 1)) == NULL) {
-#ifdef DEBUG
-                       (void)fprintf(stderr, "Malloc failed (%s)\n",
-                           strerror(errno));
-#endif
+               *newch = CAST(unsigned char *, malloc(HOWMANY + 1));
+               if (*newch == NULL) {
+                       DPRINTF("Malloc failed (%s)\n", strerror(errno));
                        n = NODATA;
                        goto err;
                }
                if ((r = sread(fdout[0], *newch, HOWMANY, 0)) <= 0) {
-                       DPRINTF("Read failed (%s)\n", strerror(errno));
+                       DPRINTF("Read failed %d (%s)\n", fdout[0],
+                               r != -1 ? strerror(errno) : "no data");
                        free(*newch);
                        n = NODATA;
                        *newch = NULL;
@@ -586,9 +605,13 @@ uncompressbuf(struct magic_set *ms, int fd, size_t method,
                /* NUL terminate, as every buffer is handled here. */
                (*newch)[n] = '\0';
 err:
-               if (fdin[1] != -1)
+               if (fdin[1] != -1) {
                        (void) close(fdin[1]);
+                       fdin[1] = -1;
+               }
                (void) close(fdout[0]);
+               fdout[0] = -1;
+               DPRINTF("Child wait return %#x\n", status);
                if (wait(&status) == -1) {
                        DPRINTF("Wait failed (%s)\n", strerror(errno));
                        n = NODATA;
@@ -599,6 +622,7 @@ err:
                }
 
                (void) close(fdin[0]);
+               DPRINTF("Returning n=%zd\n", n);
            
                return n;
        }