Check pipe size for possible blocking
diff --git a/CHANGES b/CHANGES
index f1b79b6..8e5fb7a 100644
--- a/CHANGES
+++ b/CHANGES
@@ -166,6 +166,10 @@
Filan prints the current value.
Tests: STDIN_F_SETPIPE_SZ EXEC_F_SETPIPE_SZ
+ Bidirectional PIPE addresses may block on writing a data chunk larger
+ than pipe buffer. Socat now tries to detect if transfer block size is
+ large enough and issues a warning.
+
Corrections:
When a sub process (EXEC, SYSTEM) terminated with exit code other than
0, its last sent data might have been lost depending on timing of read/
diff --git a/socat.c b/socat.c
index 8632093..c857b0b 100644
--- a/socat.c
+++ b/socat.c
@@ -22,10 +22,11 @@
#include "xioopts.h"
#include "xiolockfile.h"
+#include "xio-pipe.h"
+
/* command line options */
-struct {
- size_t bufsiz;
+struct socat_opts {
bool verbose;
bool verbhex;
struct timeval pollintv; /* with ignoreeof, reread after seconds */
@@ -40,7 +41,6 @@
unsigned long log_sigs; /* signals to be caught just for logging */
bool statistics; /* log statistics on exit */
} socat_opts = {
- 8192, /* bufsiz */
false, /* verbose */
false, /* verbhex */
{1,0}, /* pollintv */
@@ -234,7 +234,7 @@
Exit(1);
}
}
- socat_opts.bufsiz = Strtoul(a, (char **)&a, 0, "-b");
+ xioparms.bufsiz = Strtoul(a, (char **)&a, 0, "-b");
break;
case 's': if (arg1[0][2]) { socat_opt_hint(stderr, arg1[0][1], arg1[0][2]); Exit(1); }
diag_set_int('e', E_FATAL); break;
@@ -936,9 +936,9 @@
#endif /* WITH_FILAN */
/* when converting nl to crnl, size might double */
- if (socat_opts.bufsiz > (SIZE_MAX-1)/2) {
- Error2("buffer size option (-b) to big - "F_Zu" (max is "F_Zu")", socat_opts.bufsiz, (SIZE_MAX-1)/2);
- socat_opts.bufsiz = (SIZE_MAX-1)/2;
+ if (xioparms.bufsiz > (SIZE_MAX-1)/2) {
+ Error2("buffer size option (-b) to big - "F_Zu" (max is "F_Zu")", xioparms.bufsiz, (SIZE_MAX-1)/2);
+ xioparms.bufsiz = (SIZE_MAX-1)/2;
}
#if HAVE_PROTOTYPE_LIB_posix_memalign
@@ -946,13 +946,13 @@
Without this, eg.read() fails with "Invalid argument" */
{
int _errno;
- if ((_errno = Posix_memalign((void **)&buff, getpagesize(), 2*socat_opts.bufsiz+1)) != 0) {
+ if ((_errno = Posix_memalign((void **)&buff, getpagesize(), 2*xioparms.bufsiz+1)) != 0) {
Error1("posix_memalign(): %s", strerror(_errno));
return -1;
}
}
#else /* !HAVE_PROTOTYPE_LIB_posix_memalign */
- buff = Malloc(2*socat_opts.bufsiz+1);
+ buff = Malloc(2*xioparms.bufsiz+1);
if (buff == NULL) return -1;
#endif /* !HAVE_PROTOTYPE_LIB_posix_memalign */
@@ -1180,7 +1180,7 @@
if (mayrd1 && maywr2) {
mayrd1 = false;
- if ((bytes1 = xiotransfer(sock1, sock2, buff, socat_opts.bufsiz, false))
+ if ((bytes1 = xiotransfer(sock1, sock2, buff, xioparms.bufsiz, false))
< 0) {
if (errno != EAGAIN) {
closing = MAX(closing, 1);
@@ -1212,7 +1212,7 @@
if (mayrd2 && maywr1) {
mayrd2 = false;
- if ((bytes2 = xiotransfer(sock2, sock1, buff, socat_opts.bufsiz, true))
+ if ((bytes2 = xiotransfer(sock2, sock1, buff, xioparms.bufsiz, true))
< 0) {
if (errno != EAGAIN) {
closing = MAX(closing, 1);
@@ -1633,7 +1633,7 @@
from = '\r';
}
if (buf2 == NULL) {
- if ((buf2 = Malloc(socat_opts.bufsiz)) == NULL) {
+ if ((buf2 = Malloc(xioparms.bufsiz)) == NULL) {
return -1;
}
}
diff --git a/xio-pipe.c b/xio-pipe.c
index 718333f..da17b8a 100644
--- a/xio-pipe.c
+++ b/xio-pipe.c
@@ -74,6 +74,9 @@
showleft(opts);
Error1("INTERNAL: %d option(s) remained unused", numleft);
}
+
+ xio_chk_pipesz(sfd->fd);
+
Notice("writing to and reading from unnamed pipe");
return 0;
}
@@ -183,7 +186,45 @@
applyopts_named(pipename, opts, PH_FD);
applyopts(sfd, -1, opts, PH_FD);
applyopts_cloexec(sfd->fd, opts);
+ xio_chk_pipesz(sfd->fd);
+
return _xio_openlate(sfd, opts);
}
+
+/* Checks if fd is a pipe and if its buffer is at least the blksiz.
+ returns 0 if ok;
+ returns 1 if unknown;
+ returns -1 if not */
+int xio_chk_pipesz(
+ int fd)
+{
+ struct stat st;
+ int pipesz;
+
+ if (fstat(fd, &st) < 0) {
+ Warn2("fstat(%d, ...): %s", fd, strerror(errno));
+ return 1;
+ }
+ if ((st.st_mode&S_IFMT) != S_IFIFO) {
+ return 0;
+ }
+
+#if defined(F_GETPIPE_SZ)
+ if ((pipesz = Fcntl(fd, F_GETPIPE_SZ)) < 0) {
+ Warn2("fcntl(%d, F_GETPIPE_SZ): %s", fd, strerror(errno));
+ return 1;
+ }
+
+ if (pipesz >= xioparms.bufsiz)
+ return 0;
+
+ Warn3("xio_chk_pipesz(%d, ...): Socat block size "F_Zu" is larger than pipe size %d, might block; use option f-setpipe-sz!",
+ fd, xioparms.bufsiz, pipesz);
+ return -1;
+#else /* !defined(F_GETPIPE_SZ) */
+ return 1;
+#endif /* !defined(F_GETPIPE_SZ) */
+}
+
#endif /* WITH_PIPE */
diff --git a/xio-pipe.h b/xio-pipe.h
index 7171e6b..ef3e06b 100644
--- a/xio-pipe.h
+++ b/xio-pipe.h
@@ -9,4 +9,6 @@
extern const struct optdesc opt_f_setpipe_sz;
+extern int xio_chk_pipesz(int fd);
+
#endif /* !defined(__xio_pipe_h_included) */
diff --git a/xio-progcall.c b/xio-progcall.c
index 5a0f54d..9b302f0 100644
--- a/xio-progcall.c
+++ b/xio-progcall.c
@@ -330,7 +330,7 @@
if (rw != XIO_RDONLY) {
applyopts_cloexec(wrpip[1], popts);
if (sfd->dtype == XIODATA_2PIPE)
- applyopts(NULL, wrpip[1], popts, PH_FD);
+ applyopts(NULL, wrpip[1], popts2, PH_FD);
else
applyopts(NULL, wrpip[1], popts, PH_FD);
applyopts(NULL, wrpip[0], copts, PH_FD);
diff --git a/xio.h b/xio.h
index 9af9d96..71bddc6 100644
--- a/xio.h
+++ b/xio.h
@@ -104,7 +104,7 @@
#endif
/* global XIO options/parameters */
-typedef struct {
+typedef struct xioparms {
bool strictopts;
const char *pipesep;
const char *paramsep;
@@ -119,6 +119,7 @@
bool experimental; /* enable some features */
const char *sniffleft_name; /* file name with -r */
const char *sniffright_name; /* file name with -R */
+ size_t bufsiz;
} xioparms_t;
/* pack the description of a lock file */
diff --git a/xioparam.c b/xioparam.c
index 11830c5..b2b1406 100644
--- a/xioparam.c
+++ b/xioparam.c
@@ -23,7 +23,8 @@
WITH_DEFAULT_IPV, /* preferred_ip */
false, /* experimental */
NULL, /* sniffleft_name */
- NULL /* sniffright_name */
+ NULL, /* sniffright_name */
+ 8192 /* bufsiz */
} ;
