[PATCH] openggsn[master]: lib/tun.c: Proper cleanup during tun_new() error paths

[Harald Welte]

Review at  https://gerrit.osmocom.org/3843

lib/tun.c: Proper cleanup during tun_new() error paths

Change-Id: I285be20df76774ac7258b6edb3d4f2d28703757d
---
M lib/tun.c
1 file changed, 32 insertions(+), 13 deletions(-)


  git pull ssh://gerrit.osmocom.org:29418/openggsn refs/changes/43/3843/1

diff --git a/lib/tun.c b/lib/tun.c
index c4b7d10..6ca9be7 100644
--- a/lib/tun.c
+++ b/lib/tun.c
@@ -748,7 +748,7 @@
        /* Open the actual tun device */
        if (((*tun)->fd = open("/dev/net/tun", O_RDWR)) < 0) {
                SYS_ERR(DTUN, LOGL_ERROR, errno, "open() failed");
-               return -1;
+               goto err_free;
        }
 
        /* Set device flags. For some weird reason this is also the method
@@ -757,8 +757,7 @@
        ifr.ifr_flags = IFF_TUN | IFF_NO_PI;    /* Tun device, no packet info */
        if (ioctl((*tun)->fd, TUNSETIFF, (void *)&ifr) < 0) {
                SYS_ERR(DTUN, LOGL_ERROR, errno, "ioctl() failed");
-               close((*tun)->fd);
-               return -1;
+               goto err_close;
        }
 
        strncpy((*tun)->devname, ifr.ifr_name, IFNAMSIZ);
@@ -780,7 +779,7 @@
        if ((*tun)->fd < 0) {
                SYS_ERR(DTUN, LOGL_ERROR, errno,
                        "Can't find tunnel device");
-               return -1;
+               goto err_free;
        }
 
        snprintf((*tun)->devname, sizeof((*tun)->devname), "tun%d", devnum);
@@ -798,7 +797,7 @@
        /* Create a channel to the NET kernel. */
        if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
                SYS_ERR(DTUN, LOGL_ERROR, errno, "socket() failed");
-               return -1;
+               goto err_close;
        }
 
        /* Delete any IP addresses until SIOCDIFADDR fails */
@@ -812,45 +811,53 @@
        if ((ip_fd = open("/dev/udp", O_RDWR, 0)) < 0) {
                SYS_ERR(DTUN, LOGL_ERROR, errno,
                        "Can't open /dev/udp");
-               return -1;
+               goto err_free;
        }
 
        if (((*tun)->fd = open("/dev/tun", O_RDWR, 0)) < 0) {
                SYS_ERR(DTUN, LOGL_ERROR, errno,
                        "Can't open /dev/tun");
-               return -1;
+               close(ip_fd);
+               goto err_free;
        }
 
        /* Assign a new PPA and get its unit number. */
        if ((ppa = ioctl((*tun)->fd, TUNNEWPPA, -1)) < 0) {
                SYS_ERR(DTUN, LOGL_ERROR, errno,
                        "Can't assign new interface");
-               return -1;
+               goto sun_close_ip;
        }
 
        if ((if_fd = open("/dev/tun", O_RDWR, 0)) < 0) {
                SYS_ERR(DTUN, LOGL_ERROR, errno,
                        "Can't open /dev/tun (2)");
-               return -1;
+               goto sun_close_ip;
        }
        if (ioctl(if_fd, I_PUSH, "ip") < 0) {
                SYS_ERR(DTUN, LOGL_ERROR, errno,
                        "Can't push IP module");
-               return -1;
+               goto sun_close_if;
        }
 
        /* Assign ppa according to the unit number returned by tun device */
        if (ioctl(if_fd, IF_UNITSEL, (char *)&ppa) < 0) {
                SYS_ERR(DTUN, LOGL_ERROR, errno, "Can't set PPA %d",
                        ppa);
-               return -1;
+               goto sun_close_if;
        }
 
        /* Link the two streams */
        if ((muxid = ioctl(ip_fd, I_LINK, if_fd)) < 0) {
                SYS_ERR(DTUN, LOGL_ERROR, errno,
                        "Can't link TUN device to IP");
-               return -1;
+               goto sun_close_if;
+       }
+
+       /* Link the two streams */
+       if ((muxid = ioctl(ip_fd, I_LINK, if_fd)) < 0) {
+               SYS_ERR(DTUN, LOGL_ERROR, errno,
+                       "Can't link TUN device to IP");
+               goto sun_close_if;
        }
 
        close(if_fd);
@@ -866,7 +873,7 @@
                ioctl(ip_fd, I_PUNLINK, muxid);
                SYS_ERR(DTUN, LOGL_ERROR, errno,
                        "Can't set multiplexor id");
-               return -1;
+               goto sun_close_ip;
        }
 
        /*  if (fcntl (fd, F_SETFL, O_NONBLOCK) < 0)
@@ -874,10 +881,22 @@
 
        return 0;
 
+sun_close_if:
+       close(if_fd);
+sun_close_ip:
+       close(ip_fd);
+       goto err_close;
+
 #else
 #error  "Unknown platform!"
 #endif
 
+err_close:
+       close((*tun)->fd);
+err_free:
+       free(*tun);
+       *tun = NULL;
+       return -1;
 }
 
 int tun_free(struct tun_t *tun)

-- 
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Gerrit-MessageType: newchange
Gerrit-Change-Id: I285be20df76774ac7258b6edb3d4f2d28703757d
Gerrit-PatchSet: 1
Gerrit-Project: openggsn
Gerrit-Branch: master
Gerrit-Owner: Harald Welte <lafo...@gnumonks.org>