hush: fix read builtin to not read ahead past eol and to not use

insane amounts of stack. Testsuite updated.

diff --git a/include/libbb.h b/include/libbb.h
index ce62f45..5aa95ea 100644 (file)
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -400,7 +400,11 @@ extern ssize_t safe_read(int fd, void *buf, size_t count);
 extern ssize_t full_read(int fd, void *buf, size_t count);
 extern void xread(int fd, void *buf, size_t count);
 extern unsigned char xread_char(int fd);
+// Read one line a-la fgets. Uses one read(), works only on seekable streams
 extern char *reads(int fd, char *buf, size_t count);
+// Read one line a-la fgets. Reads byte-by-byte.
+// Useful when it is important to not read ahead.
+extern char *xmalloc_reads(int fd, char *pfx);
 extern ssize_t read_close(int fd, void *buf, size_t count);
 extern ssize_t open_read_close(const char *filename, void *buf, size_t count);
 extern void *xmalloc_open_read_close(const char *filename, size_t *sizep);

diff --git a/libbb/read.c b/libbb/read.c
index c05b26b..05bf754 100644 (file)
--- a/libbb/read.c
+++ b/libbb/read.c
@@ -38,10 +38,8 @@ ssize_t full_read(int fd, void *buf, size_t len)
 
                if (cc < 0)
                        return cc;      /* read() returns -1 on failure. */
-
                if (cc == 0)
                        break;
-
                buf = ((char *)buf) + cc;
                total += cc;
                len -= cc;
@@ -64,9 +62,7 @@ void xread(int fd, void *buf, size_t count)
 unsigned char xread_char(int fd)
 {
        char tmp;
-
        xread(fd, &tmp, 1);
-
        return tmp;
 }
 
@@ -95,6 +91,37 @@ char *reads(int fd, char *buffer, size_t size)
        return buffer;
 }
 
+// Read one line a-la fgets. Reads byte-by-byte.
+// Useful when it is important to not read ahead.
+char *xmalloc_reads(int fd, char *buf)
+{
+       char *p;
+       int sz = buf ? strlen(buf) : 0;
+
+       goto jump_in;
+       while (1) {
+               if (p - buf == sz) {
+ jump_in:
+                       buf = xrealloc(buf, sz + 128);
+                       p = buf + sz;
+                       sz += 128;
+               }
+               if (safe_read(fd, p, 1) != 1) { /* EOF/error */
+                       if (p == buf) {
+                               /* we read nothing [and buf was NULL initially] */
+                               free(buf);
+                               return NULL;
+                       }
+                       break;
+               }
+               if (*p == '\n')
+                       break;
+               p++;
+       }
+       *p++ = '\0';
+       return xrealloc(buf, p - buf);
+}
+
 ssize_t read_close(int fd, void *buf, size_t size)
 {
        int e;
@@ -113,25 +140,29 @@ ssize_t open_read_close(const char *filename, void *buf, size_t size)
        return read_close(fd, buf, size);
 }
 
+// Read (potentially big) files in one go. File size is estimated by
+// lseek to end.
 void *xmalloc_open_read_close(const char *filename, size_t *sizep)
 {
        char *buf;
        size_t size = sizep ? *sizep : INT_MAX;
-       int fd = xopen(filename, O_RDONLY);
+       int fd;
+       off_t len;
+
+       fd = xopen(filename, O_RDONLY);
        /* /proc/N/stat files report len 0 here */
        /* In order to make such files readable, we add small const */
-       off_t len = xlseek(fd, 0, SEEK_END) + 256;
+       len = xlseek(fd, 0, SEEK_END) | 0x3ff; /* + up to 1k */
        xlseek(fd, 0, SEEK_SET);
-
-       if (len > size)
-               bb_error_msg_and_die("file '%s' is too big", filename);
-       size = len;
+       if (len < size)
+               size = len;
        buf = xmalloc(size + 1);
        size = read_close(fd, buf, size);
        if ((ssize_t)size < 0)
                bb_perror_msg_and_die("'%s'", filename);
        xrealloc(buf, size + 1);
        buf[size] = '\0';
-       if (sizep) *sizep = size;
+       if (sizep)
+               *sizep = size;
        return buf;
 }

diff --git a/modutils/insmod.c b/modutils/insmod.c
index a81ca7f..b9d8a02 100644 (file)
--- a/modutils/insmod.c
+++ b/modutils/insmod.c
@@ -4262,6 +4262,7 @@ int insmod_ng_main(int argc, char **argv)
 {
        long ret;
        size_t len;
+       int optlen;
        void *map;
        char *filename, *options;
 
@@ -4270,12 +4271,12 @@ int insmod_ng_main(int argc, char **argv)
                bb_show_usage();
 
        /* Rest is options */
-       options = xstrdup("");
+       options = xzalloc(1);
+       optlen = 0;
        while (*++argv) {
-               int optlen = strlen(options);
                options = xrealloc(options, optlen + 2 + strlen(*argv) + 2);
                /* Spaces handled by "" pairs, but no way of escaping quotes */
-               sprintf(options + optlen, (strchr(*argv,' ') ? "\"%s\" " : "%s "), *argv);
+               optlen += sprintf(options + optlen, (strchr(*argv,' ') ? "\"%s\" " : "%s "), *argv);
        }
 
 #if 0

diff --git a/modutils/modprobe.c b/modutils/modprobe.c
index a7c6307..dbed4ea 100644 (file)
--- a/modutils/modprobe.c
+++ b/modutils/modprobe.c
@@ -234,7 +234,7 @@ static void include_conf(struct dep_t **first, struct dep_t **current, char *buf
 {
        int continuation_line = 0;
 
-       // alias parsing is not 100% correct (no correct handling of continuation lines within an alias) !
+       // alias parsing is not 100% correct (no correct handling of continuation lines within an alias)!
 
        while (reads(fd, buffer, buflen)) {
                int l;

diff --git a/shell/README b/shell/README
index a09353d..b86f96c 100644 (file)
--- a/shell/README
+++ b/shell/README
@@ -1,5 +1,8 @@
 Various bits of what is known about busybox shells, in no particular order.
 
+2007-06-13
+hush: exec <"$1" doesn't do parameter subst
+
 2007-05-24
 hush: environment-related memory leak plugged, with net code size
 decrease.

diff --git a/shell/ash.c b/shell/ash.c
index ae078e6..173beb1 100644 (file)
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -11567,8 +11567,8 @@ readcmd(int argc, char **argv)
 #endif
 #if ENABLE_ASH_READ_TIMEOUT
        if (ts.tv_sec || ts.tv_usec) {
-               FD_ZERO (&set);
-               FD_SET (0, &set);
+               FD_ZERO(&set);
+               FD_SET(0, &set);
 
                i = select(FD_SETSIZE, &set, NULL, NULL, &ts);
                if (!i) {

diff --git a/shell/hush.c b/shell/hush.c
index 40bcafd..e6fa3d9 100644 (file)
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -942,21 +942,11 @@ static int builtin_pwd(char **argv ATTRIBUTE_UNUSED)
 /* built-in 'read VAR' handler */
 static int builtin_read(char **argv)
 {
-       char string[BUFSIZ];
-       char *p;
+       char *string;
        const char *name = argv[1] ? argv[1] : "REPLY";
-       int name_len = strlen(name);
 
-       if (name_len >= sizeof(string) - 2)
-               return EXIT_FAILURE;
-       strcpy(string, name);
-       p = string + name_len;
-       *p++ = '=';
-       *p = '\0'; /* In case stdin has only EOF */
-       /* read string. name_len+1 chars are already used by 'name=' */
-       fgets(p, sizeof(string) - 1 - name_len, stdin);
-       chomp(p);
-       return set_local_var(xstrdup(string), 0);
+       string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name));
+       return set_local_var(string, 0);
 }
 
 /* built-in 'set [VAR=value]' handler */

diff --git a/shell/hush_test/hush-misc/read.right b/shell/hush_test/hush-misc/read.right
new file mode 100644 (file)
index 0000000..0e50e2a
--- /dev/null
+++ b/shell/hush_test/hush-misc/read.right
@@ -0,0 +1,4 @@
+read
+cat
+echo "REPLY=$REPLY"
+REPLY=exec <read.tests

diff --git a/shell/hush_test/hush-misc/read.tests b/shell/hush_test/hush-misc/read.tests
new file mode 100755 (executable)
index 0000000..ff1acbd
--- /dev/null
+++ b/shell/hush_test/hush-misc/read.tests
@@ -0,0 +1,4 @@
+exec <read.tests
+read
+cat
+echo "REPLY=$REPLY"

diff --git a/util-linux/readprofile.c b/util-linux/readprofile.c
index f2bd3bb..02afedc 100644 (file)
--- a/util-linux/readprofile.c
+++ b/util-linux/readprofile.c
@@ -99,7 +99,7 @@ int readprofile_main(int argc, char **argv)
        /*
         * Use an fd for the profiling buffer, to skip stdio overhead
         */
-       len = INT_MAX;
+       len = MAXINT(ssize_t);
        buf = xmalloc_open_read_close(proFile, &len);
        if (!optNative) {
                int entries = len/sizeof(*buf);