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Remove the setjmp/longjmp stuff completely. Use signal

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handlers to set flags only (with exception for sigquit(),
which still seems to call some non-reentrant functions on
its way to _exit(2).)  That must eliminate the possibility
of catching SIGSEGV from following non-reentrant paths from
signal handlers.

PR:		bin/32740 bin/33846
Submitted by:	Maxim Konovalov <maxim@macomnet.ru>
Obtained from:	OpenBSD
This commit is contained in:
Yaroslav Tykhiy 2002-01-28 19:28:14 +00:00
parent 5cc5c73a03
commit 4b82fc955f
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=89935
2 changed files with 94 additions and 44 deletions
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21
libexec/ftpd/ftpcmd.y
View File

@ -60,7 +60,6 @@ static const char rcsid[] =
#include <glob.h>
#include <netdb.h>
#include <pwd.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
@ -101,6 +100,7 @@ off_t restart_point;
static int cmd_type;
static int cmd_form;
static int cmd_bytesz;
static int state;
char cbuf[512];
char *fromname = (char *) 0;
@ -750,9 +750,11 @@ cmd
reply(221, "Goodbye.");
dologout(0);
}
| error CRLF
| error
{
yyerrok;
yyclearin; /* discard lookahead data */
yyerrok; /* clear error condition */
state = 0; /* reset lexer state */
}
;
rcmd
@ -1047,8 +1049,6 @@ check_login_ro
%%
extern jmp_buf errcatch;
#define CMD 0 /* beginning of command */
#define ARGS 1 /* expect miscellaneous arguments */
#define STR1 2 /* expect SP followed by STRING */
@ -1253,7 +1253,7 @@ toolong(signo)
static int
yylex()
{
static int cpos, state;
static int cpos;
char *cp, *cp2;
struct tab *p;
int n;
@ -1290,8 +1290,7 @@ yylex()
if (p != 0) {
if (p->implemented == 0) {
nack(p->name);
longjmp(errcatch,0);
/* NOTREACHED */
return (LEXERR);
}
state = p->state;
yylval.s = p->name;
@ -1316,8 +1315,7 @@ yylex()
if (p->implemented == 0) {
state = CMD;
nack(p->name);
longjmp(errcatch,0);
/* NOTREACHED */
return (LEXERR);
}
state = p->state;
yylval.s = p->name;
@ -1467,9 +1465,8 @@ yylex()
default:
fatalerror("Unknown state in scanner.");
}
yyerror((char *) 0);
state = CMD;
longjmp(errcatch,0);
return (LEXERR);
}
}

117
libexec/ftpd/ftpd.c
View File

@ -79,7 +79,6 @@ static const char rcsid[] =
#include <pwd.h>
#include <grp.h>
#include <opie.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
@ -125,7 +124,6 @@ union sockunion pasv_addr;
int daemon_mode;
int data;
jmp_buf errcatch, urgcatch;
int logged_in;
struct passwd *pw;
int ftpdebug;
@ -150,6 +148,7 @@ int noepsv=0; /* EPSV command is disabled. */
int noretr=0; /* RETR command is disabled. */
int noguestretr=0; /* RETR command is disabled for anon users. */
static volatile sig_atomic_t recvurg;
sig_atomic_t transflag;
off_t file_size;
off_t byte_count;
@ -243,7 +242,8 @@ static void inithosts __P((void));
static void selecthost __P((union sockunion *));
#endif
static void ack __P((char *));
static void myoob __P((int));
static void sigurg __P((int));
static void myoob __P((void));
static int checkuser __P((char *, char *, int));
static FILE *dataconn __P((char *, off_t, char *));
static void dolog __P((struct sockaddr *));
@ -252,8 +252,9 @@ static void end_login __P((void));
static FILE *getdatasock __P((char *));
static char *gunique __P((char *));
static void lostconn __P((int));
static void sigquit __P((int));
static int receive_data __P((FILE *, FILE *));
static void send_data __P((FILE *, FILE *, off_t, off_t, int));
static int send_data __P((FILE *, FILE *, off_t, off_t, int));
static struct passwd *
sgetpwnam __P((char *));
static char *sgetsave __P((char *));
@ -286,8 +287,11 @@ main(argc, argv, envp)
char *bindname = NULL;
int family = AF_UNSPEC;
int enable_v4 = 0;
struct sigaction sa;
tzset(); /* in case no timezone database in ~ftp */
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
#ifdef OLD_SETPROCTITLE
/*
@ -419,7 +423,8 @@ main(argc, argv, envp)
syslog(LOG_ERR, "failed to become a daemon");
exit(1);
}
(void) signal(SIGCHLD, reapchild);
sa.sa_handler = reapchild;
(void)sigaction(SIGCHLD, &sa, NULL);
/* init bind_sa */
memset(&hints, 0, sizeof(hints));
@ -522,10 +527,23 @@ main(argc, argv, envp)
}
}
(void) signal(SIGCHLD, SIG_IGN);
(void) signal(SIGPIPE, lostconn);
if (signal(SIGURG, myoob) == SIG_ERR)
syslog(LOG_ERR, "signal: %m");
sa.sa_handler = SIG_DFL;
(void)sigaction(SIGCHLD, &sa, NULL);
sa.sa_handler = sigurg;
sa.sa_flags = 0; /* don't restart syscalls for SIGURG */
(void)sigaction(SIGURG, &sa, NULL);
sigfillset(&sa.sa_mask); /* block all signals in handler */
sa.sa_flags = SA_RESTART;
sa.sa_handler = sigquit;
(void)sigaction(SIGHUP, &sa, NULL);
(void)sigaction(SIGINT, &sa, NULL);
(void)sigaction(SIGQUIT, &sa, NULL);
(void)sigaction(SIGTERM, &sa, NULL);
sa.sa_handler = lostconn;
(void)sigaction(SIGPIPE, &sa, NULL);
addrlen = sizeof(ctrl_addr);
if (getsockname(0, (struct sockaddr *)&ctrl_addr, &addrlen) < 0) {
@ -610,7 +628,6 @@ main(argc, argv, envp)
hostname[MAXHOSTNAMELEN - 1] = '\0';
#endif
reply(220, "%s FTP server (%s) ready.", hostname, version);
(void) setjmp(errcatch);
for (;;)
(void) yyparse();
/* NOTREACHED */
@ -626,6 +643,15 @@ lostconn(signo)
dologout(1);
}
static void
sigquit(signo)
int signo;
{
syslog(LOG_ERR, "got signal %d", signo);
dologout(1);
}
#ifdef VIRTUAL_HOSTING
/*
* read in virtual host tables (if they exist)
@ -1770,7 +1796,7 @@ dataconn(name, size, mode)
*
* NB: Form isn't handled.
*/
static void
static int
send_data(instr, outstr, blksize, filesize, isreg)
FILE *instr, *outstr;
off_t blksize;
@ -1783,14 +1809,12 @@ send_data(instr, outstr, blksize, filesize, isreg)
off_t cnt;
transflag++;
if (setjmp(urgcatch)) {
transflag = 0;
return;
}
switch (type) {
case TYPE_A:
while ((c = getc(instr)) != EOF) {
if (recvurg)
goto got_oob;
byte_count++;
if (c == '\n') {
if (ferror(outstr))
@ -1799,6 +1823,8 @@ send_data(instr, outstr, blksize, filesize, isreg)
}
(void) putc(c, outstr);
}
if (recvurg)
goto got_oob;
fflush(outstr);
transflag = 0;
if (ferror(instr))
@ -1806,7 +1832,7 @@ send_data(instr, outstr, blksize, filesize, isreg)
if (ferror(outstr))
goto data_err;
reply(226, "Transfer complete.");
return;
return (0);
case TYPE_I:
case TYPE_L:
@ -1828,6 +1854,8 @@ send_data(instr, outstr, blksize, filesize, isreg)
while (err != -1 && cnt < filesize) {
err = sendfile(filefd, netfd, offset, len,
(struct sf_hdtr *) NULL, &cnt, 0);
if (recvurg)
goto got_oob;
byte_count += cnt;
offset += cnt;
len -= cnt;
@ -1841,14 +1869,14 @@ send_data(instr, outstr, blksize, filesize, isreg)
}
reply(226, "Transfer complete.");
return;
return (0);
}
oldway:
if ((buf = malloc((u_int)blksize)) == NULL) {
transflag = 0;
perror_reply(451, "Local resource failure: malloc");
return;
return (-1);
}
while ((cnt = read(filefd, buf, (u_int)blksize)) > 0 &&
@ -1862,21 +1890,28 @@ send_data(instr, outstr, blksize, filesize, isreg)
goto data_err;
}
reply(226, "Transfer complete.");
return;
return (0);
default:
transflag = 0;
reply(550, "Unimplemented TYPE %d in send_data", type);
return;
return (-1);
}
data_err:
transflag = 0;
perror_reply(426, "Data connection");
return;
return (-1);
file_err:
transflag = 0;
perror_reply(551, "Error on input file");
return (-1);
got_oob:
myoob();
recvurg = 0;
transflag = 0;
return (-1);
}
/*
@ -1894,11 +1929,6 @@ receive_data(instr, outstr)
char buf[BUFSIZ];
transflag++;
if (setjmp(urgcatch)) {
transflag = 0;
return (-1);
}
bare_lfs = 0;
switch (type) {
@ -1906,10 +1936,14 @@ receive_data(instr, outstr)
case TYPE_I:
case TYPE_L:
while ((cnt = read(fileno(instr), buf, sizeof(buf))) > 0) {
if (recvurg)
goto got_oob;
if (write(fileno(outstr), buf, cnt) != cnt)
goto file_err;
byte_count += cnt;
}
if (recvurg)
goto got_oob;
if (cnt < 0)
goto data_err;
transflag = 0;
@ -1922,6 +1956,8 @@ receive_data(instr, outstr)
case TYPE_A:
while ((c = getc(instr)) != EOF) {
if (recvurg)
goto got_oob;
byte_count++;
if (c == '\n')
bare_lfs++;
@ -1937,6 +1973,8 @@ receive_data(instr, outstr)
(void) putc(c, outstr);
contin2: ;
}
if (recvurg)
goto got_oob;
fflush(outstr);
if (ferror(instr))
goto data_err;
@ -1965,6 +2003,12 @@ receive_data(instr, outstr)
transflag = 0;
perror_reply(452, "Error writing file");
return (-1);
got_oob:
myoob();
recvurg = 0;
transflag = 0;
return (-1);
}
void
@ -2384,8 +2428,15 @@ dologout(status)
}
static void
myoob(signo)
sigurg(signo)
int signo;
{
recvurg = 1;
}
static void
myoob()
{
char *cp;
@ -2402,7 +2453,6 @@ myoob(signo)
tmpline[0] = '\0';
reply(426, "Transfer aborted. Data connection closed.");
reply(226, "Abort successful");
longjmp(urgcatch, 1);
}
if (strcmp(cp, "STAT\r\n") == 0) {
tmpline[0] = '\0';
@ -2718,10 +2768,6 @@ send_file_list(whichf)
simple = 1;
}
if (setjmp(urgcatch)) {
transflag = 0;
goto out;
}
while ((dirname = *dirlist++)) {
if (stat(dirname, &st) < 0) {
/*
@ -2763,6 +2809,13 @@ send_file_list(whichf)
while ((dir = readdir(dirp)) != NULL) {
char nbuf[MAXPATHLEN];
if (recvurg) {
myoob();
recvurg = 0;
transflag = 0;
goto out;
}
if (dir->d_name[0] == '.' && dir->d_namlen == 1)
continue;
if (dir->d_name[0] == '.' && dir->d_name[1] == '.' &&