- djm@cvs.openbsd.org 2006/07/06 10:47:57

     [sftp-server.8 sftp-server.c]
     add commandline options to enable logging of transactions; ok markus@

1 files changed, 261 insertions, 56 deletions

diff --git a/sftp-server.c b/sftp-server.c
index e842341cb..e882216b1 100644
--- a/sftp-server.c
+++ b/sftp-server.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp-server.c,v 1.57 2006/03/30 09:58:16 djm Exp $ */
+/* $OpenBSD: sftp-server.c,v 1.58 2006/07/06 10:47:57 djm Exp $ */
 /*
  * Copyright (c) 2000-2004 Markus Friedl.  All rights reserved.
  *
@@ -26,6 +26,7 @@
 #include "log.h"
 #include "xmalloc.h"
 #include "misc.h"
+#include "uidswap.h"
 
 #include "sftp.h"
 #include "sftp-common.h"
@@ -34,9 +35,13 @@
 #define get_int64()                     buffer_get_int64(&iqueue);
 #define get_int()                       buffer_get_int(&iqueue);
 #define get_string(lenp)                buffer_get_string(&iqueue, lenp);
-#define TRACE                           debug
 
-extern char *__progname;
+/* Our verbosity */
+LogLevel log_level = SYSLOG_LEVEL_ERROR;
+
+/* Our client */
+struct passwd *pw = NULL;
+char *client_addr = NULL;
 
 /* input and output queue */
 Buffer iqueue;
@@ -108,6 +113,33 @@ flags_from_portable(int pflags)
         return flags;
 }
 
+static const char *
+string_from_portable(int pflags)
+{
+        static char ret[128];
+
+        *ret = '\0';
+
+#define PAPPEND(str)    {                               \
+                if (*ret != '\0')                       \
+                        strlcat(ret, ",", sizeof(ret)); \
+                strlcat(ret, str, sizeof(ret));         \
+        }
+
+        if (pflags & SSH2_FXF_READ)
+                PAPPEND("READ")
+        if (pflags & SSH2_FXF_WRITE)
+                PAPPEND("WRITE")
+        if (pflags & SSH2_FXF_CREAT)
+                PAPPEND("CREATE")
+        if (pflags & SSH2_FXF_TRUNC)
+                PAPPEND("TRUNCATE")
+        if (pflags & SSH2_FXF_EXCL)
+                PAPPEND("EXCL")
+
+        return ret;
+}
+
 static Attrib *
 get_attrib(void)
 {
@@ -122,6 +154,7 @@ struct Handle {
         DIR *dirp;
         int fd;
         char *name;
+        u_int64_t bytes_read, bytes_write;
 };
 
 enum {
@@ -152,6 +185,7 @@ handle_new(int use, const char *name, int fd, DIR *dirp)
                         handles[i].dirp = dirp;
                         handles[i].fd = fd;
                         handles[i].name = xstrdup(name);
+                        handles[i].bytes_read = handles[i].bytes_write = 0;
                         return i;
                 }
         }
@@ -215,6 +249,36 @@ handle_to_fd(int handle)
         return -1;
 }
 
+static void
+handle_update_read(int handle, ssize_t bytes)
+{
+        if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
+                handles[handle].bytes_read += bytes;
+}
+
+static void
+handle_update_write(int handle, ssize_t bytes)
+{
+        if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
+                handles[handle].bytes_write += bytes;
+}
+
+static u_int64_t
+handle_bytes_read(int handle)
+{
+        if (handle_is_ok(handle, HANDLE_FILE))
+                return (handles[handle].bytes_read);
+        return 0;
+}
+
+static u_int64_t
+handle_bytes_write(int handle)
+{
+        if (handle_is_ok(handle, HANDLE_FILE))
+                return (handles[handle].bytes_write);
+        return 0;
+}
+
 static int
 handle_close(int handle)
 {
@@ -234,6 +298,31 @@ handle_close(int handle)
         return ret;
 }
 
+static void
+handle_log_close(int handle, char *emsg)
+{
+        if (handle_is_ok(handle, HANDLE_FILE)) {
+                logit("%s%sclose \"%s\" bytes read %llu written %llu",
+                    emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
+                    handle_to_name(handle),
+                    handle_bytes_read(handle), handle_bytes_write(handle));
+        } else {
+                logit("%s%sclosedir \"%s\"",
+                    emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
+                    handle_to_name(handle));
+        }
+}
+
+static void
+handle_log_exit(void)
+{
+        u_int i;
+
+        for (i = 0; i < sizeof(handles)/sizeof(Handle); i++)
+                if (handles[i].use != HANDLE_UNUSED)
+                        handle_log_close(i, "forced");
+}
+
 static int
 get_handle(void)
 {
@@ -260,10 +349,9 @@ send_msg(Buffer *m)
         buffer_consume(m, mlen);
 }
 
-static void
-send_status(u_int32_t id, u_int32_t status)
+static const char *
+status_to_message(u_int32_t status)
 {
-        Buffer msg;
         const char *status_messages[] = {
                 "Success",                      /* SSH_FX_OK */
                 "End of file",                  /* SSH_FX_EOF */
@@ -276,15 +364,24 @@ send_status(u_int32_t id, u_int32_t status)
                 "Operation unsupported",        /* SSH_FX_OP_UNSUPPORTED */
                 "Unknown error"                 /* Others */
         };
+        return (status_messages[MIN(status,SSH2_FX_MAX)]);
+}
 
-        TRACE("sent status id %u error %u", id, status);
+static void
+send_status(u_int32_t id, u_int32_t status)
+{
+        Buffer msg;
+
+        debug3("request %u: sent status %u", id, status);
+        if (log_level > SYSLOG_LEVEL_VERBOSE ||
+            (status != SSH2_FX_OK && status != SSH2_FX_EOF))
+                logit("sent status %s", status_to_message(status));
         buffer_init(&msg);
         buffer_put_char(&msg, SSH2_FXP_STATUS);
         buffer_put_int(&msg, id);
         buffer_put_int(&msg, status);
         if (version >= 3) {
-                buffer_put_cstring(&msg,
-                    status_messages[MIN(status,SSH2_FX_MAX)]);
+                buffer_put_cstring(&msg, status_to_message(status));
                 buffer_put_cstring(&msg, "");
         }
         send_msg(&msg);
@@ -306,7 +403,7 @@ send_data_or_handle(char type, u_int32_t id, const char *data, int dlen)
 static void
 send_data(u_int32_t id, const char *data, int dlen)
 {
-        TRACE("sent data id %u len %d", id, dlen);
+        debug("request %u: sent data len %d", id, dlen);
         send_data_or_handle(SSH2_FXP_DATA, id, data, dlen);
 }
 
@@ -317,7 +414,7 @@ send_handle(u_int32_t id, int handle)
         int hlen;
 
         handle_to_string(handle, &string, &hlen);
-        TRACE("sent handle id %u handle %d", id, handle);
+        debug("request %u: sent handle handle %d", id, handle);
         send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen);
         xfree(string);
 }
@@ -332,7 +429,7 @@ send_names(u_int32_t id, int count, const Stat *stats)
         buffer_put_char(&msg, SSH2_FXP_NAME);
         buffer_put_int(&msg, id);
         buffer_put_int(&msg, count);
-        TRACE("sent names id %u count %d", id, count);
+        debug("request %u: sent names count %d", id, count);
         for (i = 0; i < count; i++) {
                 buffer_put_cstring(&msg, stats[i].name);
                 buffer_put_cstring(&msg, stats[i].long_name);
@@ -347,7 +444,7 @@ send_attrib(u_int32_t id, const Attrib *a)
 {
         Buffer msg;
 
-        TRACE("sent attrib id %u have 0x%x", id, a->flags);
+        debug("request %u: sent attrib have 0x%x", id, a->flags);
         buffer_init(&msg);
         buffer_put_char(&msg, SSH2_FXP_ATTRS);
         buffer_put_int(&msg, id);
@@ -364,7 +461,7 @@ process_init(void)
         Buffer msg;
 
         version = get_int();
-        TRACE("client version %d", version);
+        verbose("received client version %d", version);
         buffer_init(&msg);
         buffer_put_char(&msg, SSH2_FXP_VERSION);
         buffer_put_int(&msg, SSH2_FILEXFER_VERSION);
@@ -381,12 +478,14 @@ process_open(void)
         int handle, fd, flags, mode, status = SSH2_FX_FAILURE;
 
         id = get_int();
+        debug3("request %u: open flags %d", id, pflags);
         name = get_string(NULL);
         pflags = get_int();             /* portable flags */
         a = get_attrib();
         flags = flags_from_portable(pflags);
         mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a->perm : 0666;
-        TRACE("open id %u name %s flags %d mode 0%o", id, name, pflags, mode);
+        logit("open \"%s\" flags %s mode 0%o",
+            name, string_from_portable(pflags), mode);
         fd = open(name, flags, mode);
         if (fd < 0) {
                 status = errno_to_portable(errno);
@@ -412,7 +511,8 @@ process_close(void)
 
         id = get_int();
         handle = get_handle();
-        TRACE("close id %u handle %d", id, handle);
+        debug3("request %u: close handle %u", id, handle);
+        handle_log_close(handle, NULL);
         ret = handle_close(handle);
         status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
         send_status(id, status);
@@ -431,11 +531,11 @@ process_read(void)
         off = get_int64();
         len = get_int();
 
-        TRACE("read id %u handle %d off %llu len %d", id, handle,
-            (unsigned long long)off, len);
+        debug("request %u: read \"%s\" (handle %d) off %llu len %d",
+            id, handle_to_name(handle), handle, (unsigned long long)off, len);
         if (len > sizeof buf) {
                 len = sizeof buf;
-                logit("read change len %d", len);
+                debug2("read change len %d", len);
         }
         fd = handle_to_fd(handle);
         if (fd >= 0) {
@@ -451,6 +551,7 @@ process_read(void)
                         } else {
                                 send_data(id, buf, ret);
                                 status = SSH2_FX_OK;
+                                handle_update_read(handle, ret);
                         }
                 }
         }
@@ -472,8 +573,8 @@ process_write(void)
         off = get_int64();
         data = get_string(&len);
 
-        TRACE("write id %u handle %d off %llu len %d", id, handle,
-            (unsigned long long)off, len);
+        debug("request %u: write \"%s\" (handle %d) off %llu len %d",
+            id, handle_to_name(handle), handle, (unsigned long long)off, len);
         fd = handle_to_fd(handle);
         if (fd >= 0) {
                 if (lseek(fd, off, SEEK_SET) < 0) {
@@ -487,8 +588,9 @@ process_write(void)
                                 status = errno_to_portable(errno);
                         } else if ((size_t)ret == len) {
                                 status = SSH2_FX_OK;
+                                handle_update_write(handle, ret);
                         } else {
-                                logit("nothing at all written");
+                                debug2("nothing at all written");
                         }
                 }
         }
@@ -507,7 +609,8 @@ process_do_stat(int do_lstat)
 
         id = get_int();
         name = get_string(NULL);
-        TRACE("%sstat id %u name %s", do_lstat ? "l" : "", id, name);
+        debug3("request %u: %sstat", id, do_lstat ? "l" : "");
+        verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name);
         ret = do_lstat ? lstat(name, &st) : stat(name, &st);
         if (ret < 0) {
                 status = errno_to_portable(errno);
@@ -543,7 +646,8 @@ process_fstat(void)
 
         id = get_int();
         handle = get_handle();
-        TRACE("fstat id %u handle %d", id, handle);
+        debug("request %u: fstat \"%s\" (handle %u)",
+            id, handle_to_name(handle), handle);
         fd = handle_to_fd(handle);
         if (fd  >= 0) {
                 ret = fstat(fd, &st);
@@ -582,23 +686,33 @@ process_setstat(void)
         id = get_int();
         name = get_string(NULL);
         a = get_attrib();
-        TRACE("setstat id %u name %s", id, name);
+        debug("request %u: setstat name \"%s\"", id, name);
         if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
+                logit("set \"%s\" size %llu", name, a->size);
                 ret = truncate(name, a->size);
                 if (ret == -1)
                         status = errno_to_portable(errno);
         }
         if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
+                logit("set \"%s\" mode %04o", name, a->perm);
                 ret = chmod(name, a->perm & 0777);
                 if (ret == -1)
                         status = errno_to_portable(errno);
         }
         if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
+                char buf[64];
+                time_t t = a->mtime;
+
+                strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
+                    localtime(&t));
+                logit("set \"%s\" modtime %s", name, buf);
                 ret = utimes(name, attrib_to_tv(a));
                 if (ret == -1)
                         status = errno_to_portable(errno);
         }
         if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
+                logit("set \"%s\" owner %lu group %lu", name,
+                    (u_long)a->uid, (u_long)a->gid);
                 ret = chown(name, a->uid, a->gid);
                 if (ret == -1)
                         status = errno_to_portable(errno);
@@ -614,23 +728,25 @@ process_fsetstat(void)
         u_int32_t id;
         int handle, fd, ret;
         int status = SSH2_FX_OK;
-        char *name;
 
         id = get_int();
         handle = get_handle();
         a = get_attrib();
-        TRACE("fsetstat id %u handle %d", id, handle);
+        debug("request %u: fsetstat handle %d", id, handle);
         fd = handle_to_fd(handle);
-        name = handle_to_name(handle);
-        if (fd < 0 || name == NULL) {
+        if (fd < 0) {
                 status = SSH2_FX_FAILURE;
         } else {
+                char *name = handle_to_name(handle);
+
                 if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
+                        logit("set \"%s\" size %llu", name, a->size);
                         ret = ftruncate(fd, a->size);
                         if (ret == -1)
                                 status = errno_to_portable(errno);
                 }
                 if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
+                        logit("set \"%s\" mode %04o", name, a->perm);
 #ifdef HAVE_FCHMOD
                         ret = fchmod(fd, a->perm & 0777);
 #else
@@ -640,6 +756,12 @@ process_fsetstat(void)
                                 status = errno_to_portable(errno);
                 }
                 if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
+                        char buf[64];
+                        time_t t = a->mtime;
+
+                        strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
+                            localtime(&t));
+                        logit("set \"%s\" modtime %s", name, buf);
 #ifdef HAVE_FUTIMES
                         ret = futimes(fd, attrib_to_tv(a));
 #else
@@ -649,6 +771,8 @@ process_fsetstat(void)
                                 status = errno_to_portable(errno);
                 }
                 if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
+                        logit("set \"%s\" owner %lu group %lu", name,
+                            (u_long)a->uid, (u_long)a->gid);
 #ifdef HAVE_FCHOWN
                         ret = fchown(fd, a->uid, a->gid);
 #else
@@ -671,7 +795,8 @@ process_opendir(void)
 
         id = get_int();
         path = get_string(NULL);
-        TRACE("opendir id %u path %s", id, path);
+        debug3("request %u: opendir", id);
+        logit("opendir \"%s\"", path);
         dirp = opendir(path);
         if (dirp == NULL) {
                 status = errno_to_portable(errno);
@@ -701,14 +826,15 @@ process_readdir(void)
 
         id = get_int();
         handle = get_handle();
-        TRACE("readdir id %u handle %d", id, handle);
+        debug("request %u: readdir \"%s\" (handle %d)", id,
+            handle_to_name(handle), handle);
         dirp = handle_to_dir(handle);
         path = handle_to_name(handle);
         if (dirp == NULL || path == NULL) {
                 send_status(id, SSH2_FX_FAILURE);
         } else {
                 struct stat st;
-                char pathname[1024];
+                char pathname[MAXPATHLEN];
                 Stat *stats;
                 int nstats = 10, count = 0, i;
 
@@ -755,7 +881,8 @@ process_remove(void)
 
         id = get_int();
         name = get_string(NULL);
-        TRACE("remove id %u name %s", id, name);
+        debug3("request %u: remove", id);
+        logit("remove name \"%s\"", name);
         ret = unlink(name);
         status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
         send_status(id, status);
@@ -775,7 +902,8 @@ process_mkdir(void)
         a = get_attrib();
         mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ?
             a->perm & 0777 : 0777;
-        TRACE("mkdir id %u name %s mode 0%o", id, name, mode);
+        debug3("request %u: mkdir", id);
+        logit("mkdir name \"%s\" mode 0%o", name, mode);
         ret = mkdir(name, mode);
         status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
         send_status(id, status);
@@ -791,7 +919,8 @@ process_rmdir(void)
 
         id = get_int();
         name = get_string(NULL);
-        TRACE("rmdir id %u name %s", id, name);
+        debug3("request %u: rmdir", id);
+        logit("rmdir name \"%s\"", name);
         ret = rmdir(name);
         status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
         send_status(id, status);
@@ -811,7 +940,8 @@ process_realpath(void)
                 xfree(path);
                 path = xstrdup(".");
         }
-        TRACE("realpath id %u path %s", id, path);
+        debug3("request %u: realpath", id);
+        verbose("realpath \"%s\"", path);
         if (realpath(path, resolvedname) == NULL) {
                 send_status(id, errno_to_portable(errno));
         } else {
@@ -834,7 +964,8 @@ process_rename(void)
         id = get_int();
         oldpath = get_string(NULL);
         newpath = get_string(NULL);
-        TRACE("rename id %u old %s new %s", id, oldpath, newpath);
+        debug3("request %u: rename", id);
+        logit("rename old \"%s\" new \"%s\"", oldpath, newpath);
         status = SSH2_FX_FAILURE;
         if (lstat(oldpath, &sb) == -1)
                 status = errno_to_portable(errno);
@@ -889,7 +1020,8 @@ process_readlink(void)
 
         id = get_int();
         path = get_string(NULL);
-        TRACE("readlink id %u path %s", id, path);
+        debug3("request %u: readlink", id);
+        verbose("readlink \"%s\"", path);
         if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1)
                 send_status(id, errno_to_portable(errno));
         else {
@@ -913,7 +1045,8 @@ process_symlink(void)
         id = get_int();
         oldpath = get_string(NULL);
         newpath = get_string(NULL);
-        TRACE("symlink id %u old %s new %s", id, oldpath, newpath);
+        debug3("request %u: symlink", id);
+        logit("symlink old \"%s\" new \"%s\"", oldpath, newpath);
         /* this will fail if 'newpath' exists */
         ret = symlink(oldpath, newpath);
         status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
@@ -951,8 +1084,9 @@ process(void)
         cp = buffer_ptr(&iqueue);
         msg_len = get_u32(cp);
         if (msg_len > SFTP_MAX_MSG_LENGTH) {
-                error("bad message ");
-                exit(11);
+                error("bad message from %s local user %s",
+                    client_addr, pw->pw_name);
+                cleanup_exit(11);
         }
         if (buf_len < msg_len + 4)
                 return;
@@ -1026,7 +1160,7 @@ process(void)
         }
         /* discard the remaining bytes from the current packet */
         if (buf_len < buffer_len(&iqueue))
-                fatal("iqueue grows");
+                fatal("iqueue grew unexpectedly");
         consumed = buf_len - buffer_len(&iqueue);
         if (msg_len < consumed)
                 fatal("msg_len %d < consumed %d", msg_len, consumed);
@@ -1034,24 +1168,94 @@ process(void)
                 buffer_consume(&iqueue, msg_len - consumed);
 }
 
+/* Cleanup handler that logs active handles upon normal exit */
+void
+cleanup_exit(int i)
+{
+        if (pw != NULL && client_addr != NULL) {
+                handle_log_exit();
+                logit("session closed for local user %s from [%s]",
+                    pw->pw_name, client_addr);
+        }
+        _exit(i);
+}
+
+static void
+usage(void)
+{
+        extern char *__progname;
+
+        fprintf(stderr,
+            "usage: %s [-he] [-l log_level] [-f log_facility]\n", __progname);
+        exit(1);
+}
+
 int
-main(int ac, char **av)
+main(int argc, char **argv)
 {
         fd_set *rset, *wset;
-        int in, out, max;
+        int in, out, max, ch, skipargs = 0, log_stderr = 0;
         ssize_t len, olen, set_size;
+        SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
+        char *cp;
+
+        extern int optind;
+        extern char *optarg;
+        extern char *__progname;
 
         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
         sanitise_stdfd();
 
-        /* XXX should use getopt */
+        __progname = ssh_get_progname(argv[0]);
+        log_init(__progname, log_level, log_facility, log_stderr);
+
+        while (!skipargs && (ch = getopt(argc, argv, "C:f:l:che")) != -1) {
+                switch (ch) {
+                case 'c':
+                        /*
+                         * Ignore all arguments if we are invoked as a
+                         * shell using "sftp-server -c command" 
+                         */
+                        skipargs = 1;
+                        break;
+                case 'e':
+                        log_stderr = 1;
+                        break;
+                case 'l':
+                        log_level = log_level_number(optarg);
+                        if (log_level == SYSLOG_LEVEL_NOT_SET)
+                                error("Invalid log level \"%s\"", optarg);
+                        break;
+                case 'f':
+                        log_facility = log_facility_number(optarg);
+                        if (log_level == SYSLOG_FACILITY_NOT_SET)
+                                error("Invalid log facility \"%s\"", optarg);
+                        break;
+                case 'h':
+                default:
+                        usage();
+                }
+        }
 
-        __progname = ssh_get_progname(av[0]);
-        handle_init();
+        log_init(__progname, log_level, log_facility, log_stderr);
 
-#ifdef DEBUG_SFTP_SERVER
-        log_init("sftp-server", SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 0);
-#endif
+        if ((cp = getenv("SSH_CONNECTION")) != NULL) {
+                client_addr = xstrdup(cp);
+                if ((cp = strchr(client_addr, ' ')) == NULL)
+                        fatal("Malformed SSH_CONNECTION variable: \"%s\"",
+                            getenv("SSH_CONNECTION"));
+                *cp = '\0';
+        } else
+                client_addr = xstrdup("UNKNOWN");
+
+        if ((pw = getpwuid(getuid())) == NULL)
+                fatal("No user found for uid %lu", (u_long)getuid());
+        pw = pwcopy(pw);
+
+        logit("session opened for local user %s from [%s]",
+            pw->pw_name, client_addr);
+
+        handle_init();
 
         in = dup(STDIN_FILENO);
         out = dup(STDOUT_FILENO);
@@ -1086,7 +1290,8 @@ main(int ac, char **av)
                 if (select(max+1, rset, wset, NULL, NULL) < 0) {
                         if (errno == EINTR)
                                 continue;
-                        exit(2);
+                        error("select: %s", strerror(errno));
+                        cleanup_exit(2);
                 }
 
                 /* copy stdin to iqueue */
@@ -1095,10 +1300,10 @@ main(int ac, char **av)
                         len = read(in, buf, sizeof buf);
                         if (len == 0) {
                                 debug("read eof");
-                                exit(0);
+                                cleanup_exit(0);
                         } else if (len < 0) {
-                                error("read error");
-                                exit(1);
+                                error("read: %s", strerror(errno));
+                                cleanup_exit(1);
                         } else {
                                 buffer_append(&iqueue, buf, len);
                         }
@@ -1107,8 +1312,8 @@ main(int ac, char **av)
                 if (FD_ISSET(out, wset)) {
                         len = write(out, buffer_ptr(&oqueue), olen);
                         if (len < 0) {
-                                error("write error");
-                                exit(1);
+                                error("write: %s", strerror(errno));
+                                cleanup_exit(1);
                         } else {
                                 buffer_consume(&oqueue, len);
                         }