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

insane amounts of stack. Testsuite updated.
This commit is contained in:
Denis Vlasenko 2007-06-13 06:47:47 +00:00
parent f5f75c5e82
commit d67cef2425
10 changed files with 68 additions and 31 deletions

View File

@ -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 ssize_t full_read(int fd, void *buf, size_t count);
extern void xread(int fd, void *buf, size_t count); extern void xread(int fd, void *buf, size_t count);
extern unsigned char xread_char(int fd); 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); 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 read_close(int fd, void *buf, size_t count);
extern ssize_t open_read_close(const char *filename, 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); extern void *xmalloc_open_read_close(const char *filename, size_t *sizep);

View File

@ -38,10 +38,8 @@ ssize_t full_read(int fd, void *buf, size_t len)
if (cc < 0) if (cc < 0)
return cc; /* read() returns -1 on failure. */ return cc; /* read() returns -1 on failure. */
if (cc == 0) if (cc == 0)
break; break;
buf = ((char *)buf) + cc; buf = ((char *)buf) + cc;
total += cc; total += cc;
len -= cc; len -= cc;
@ -64,9 +62,7 @@ void xread(int fd, void *buf, size_t count)
unsigned char xread_char(int fd) unsigned char xread_char(int fd)
{ {
char tmp; char tmp;
xread(fd, &tmp, 1); xread(fd, &tmp, 1);
return tmp; return tmp;
} }
@ -95,6 +91,37 @@ char *reads(int fd, char *buffer, size_t size)
return buffer; 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) ssize_t read_close(int fd, void *buf, size_t size)
{ {
int e; 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); 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) void *xmalloc_open_read_close(const char *filename, size_t *sizep)
{ {
char *buf; char *buf;
size_t size = sizep ? *sizep : INT_MAX; 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 */ /* /proc/N/stat files report len 0 here */
/* In order to make such files readable, we add small const */ /* 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); xlseek(fd, 0, SEEK_SET);
if (len < size)
if (len > size) size = len;
bb_error_msg_and_die("file '%s' is too big", filename);
size = len;
buf = xmalloc(size + 1); buf = xmalloc(size + 1);
size = read_close(fd, buf, size); size = read_close(fd, buf, size);
if ((ssize_t)size < 0) if ((ssize_t)size < 0)
bb_perror_msg_and_die("'%s'", filename); bb_perror_msg_and_die("'%s'", filename);
xrealloc(buf, size + 1); xrealloc(buf, size + 1);
buf[size] = '\0'; buf[size] = '\0';
if (sizep) *sizep = size; if (sizep)
*sizep = size;
return buf; return buf;
} }

View File

@ -4262,6 +4262,7 @@ int insmod_ng_main(int argc, char **argv)
{ {
long ret; long ret;
size_t len; size_t len;
int optlen;
void *map; void *map;
char *filename, *options; char *filename, *options;
@ -4270,12 +4271,12 @@ int insmod_ng_main(int argc, char **argv)
bb_show_usage(); bb_show_usage();
/* Rest is options */ /* Rest is options */
options = xstrdup(""); options = xzalloc(1);
optlen = 0;
while (*++argv) { while (*++argv) {
int optlen = strlen(options);
options = xrealloc(options, optlen + 2 + strlen(*argv) + 2); options = xrealloc(options, optlen + 2 + strlen(*argv) + 2);
/* Spaces handled by "" pairs, but no way of escaping quotes */ /* 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 #if 0

View File

@ -234,7 +234,7 @@ static void include_conf(struct dep_t **first, struct dep_t **current, char *buf
{ {
int continuation_line = 0; 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)) { while (reads(fd, buffer, buflen)) {
int l; int l;

View File

@ -1,5 +1,8 @@
Various bits of what is known about busybox shells, in no particular order. 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 2007-05-24
hush: environment-related memory leak plugged, with net code size hush: environment-related memory leak plugged, with net code size
decrease. decrease.

View File

@ -11567,8 +11567,8 @@ readcmd(int argc, char **argv)
#endif #endif
#if ENABLE_ASH_READ_TIMEOUT #if ENABLE_ASH_READ_TIMEOUT
if (ts.tv_sec || ts.tv_usec) { if (ts.tv_sec || ts.tv_usec) {
FD_ZERO (&set); FD_ZERO(&set);
FD_SET (0, &set); FD_SET(0, &set);
i = select(FD_SETSIZE, &set, NULL, NULL, &ts); i = select(FD_SETSIZE, &set, NULL, NULL, &ts);
if (!i) { if (!i) {

View File

@ -942,21 +942,11 @@ static int builtin_pwd(char **argv ATTRIBUTE_UNUSED)
/* built-in 'read VAR' handler */ /* built-in 'read VAR' handler */
static int builtin_read(char **argv) static int builtin_read(char **argv)
{ {
char string[BUFSIZ]; char *string;
char *p;
const char *name = argv[1] ? argv[1] : "REPLY"; const char *name = argv[1] ? argv[1] : "REPLY";
int name_len = strlen(name);
if (name_len >= sizeof(string) - 2) string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name));
return EXIT_FAILURE; return set_local_var(string, 0);
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);
} }
/* built-in 'set [VAR=value]' handler */ /* built-in 'set [VAR=value]' handler */

View File

@ -0,0 +1,4 @@
read
cat
echo "REPLY=$REPLY"
REPLY=exec <read.tests

View File

@ -0,0 +1,4 @@
exec <read.tests
read
cat
echo "REPLY=$REPLY"

View File

@ -99,7 +99,7 @@ int readprofile_main(int argc, char **argv)
/* /*
* Use an fd for the profiling buffer, to skip stdio overhead * 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); buf = xmalloc_open_read_close(proFile, &len);
if (!optNative) { if (!optNative) {
int entries = len/sizeof(*buf); int entries = len/sizeof(*buf);