swrap: Fix a TODO

Use realpath(3) instead of strncmp(3)

Signed-off-by: Anoop C S <anoopcs@redhat.com>
Reviewed-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

diff --git a/src/socket_wrapper.c b/src/socket_wrapper.c
index f9993a27d749d3b13a658c75682082cc521c8381..de5cc7ac5dc89f1ddde7e81ee414f50a94cd707b 100644 (file)
--- a/src/socket_wrapper.c
+++ b/src/socket_wrapper.c
@@ -555,7 +555,7 @@ struct swrap {
 static struct swrap swrap;
 
 /* prototypes */
-static const char *socket_wrapper_dir(void);
+static char *socket_wrapper_dir(void);
 
 #define LIBC_NAME "libc.so"
 
@@ -1284,19 +1284,25 @@ static void swrap_set_next_free(struct socket_info *si, int next_free)
        sic->meta.next_free = next_free;
 }
 
-static const char *socket_wrapper_dir(void)
+static char *socket_wrapper_dir(void)
 {
-       const char *s = getenv("SOCKET_WRAPPER_DIR");
+       char *swrap_dir = NULL;
+       char *s = getenv("SOCKET_WRAPPER_DIR");
+
        if (s == NULL) {
                return NULL;
        }
-       /* TODO use realpath(3) here, when we add support for threads */
-       if (strncmp(s, "./", 2) == 0) {
-               s += 2;
+
+       swrap_dir = realpath(s, NULL);
+       if (swrap_dir == NULL) {
+               SWRAP_LOG(SWRAP_LOG_ERROR,
+                         "Unable to resolve socket_wrapper dir path: %s",
+                         strerror(errno));
+               return NULL;
        }
 
-       SWRAP_LOG(SWRAP_LOG_TRACE, "socket_wrapper_dir: %s", s);
-       return s;
+       SWRAP_LOG(SWRAP_LOG_TRACE, "socket_wrapper_dir: %s", swrap_dir);
+       return swrap_dir;
 }
 
 static unsigned int socket_wrapper_mtu(void)
@@ -1501,12 +1507,14 @@ done:
 
 bool socket_wrapper_enabled(void)
 {
-       const char *s = socket_wrapper_dir();
+       char *s = socket_wrapper_dir();
 
        if (s == NULL) {
                return false;
        }
 
+       SAFE_FREE(s);
+
        socket_wrapper_init_sockets();
 
        return true;
@@ -1712,6 +1720,7 @@ static int convert_in_un_remote(struct socket_info *si, const struct sockaddr *i
        unsigned int prt;
        unsigned int iface;
        int is_bcast = 0;
+       char *swrap_dir = NULL;
 
        if (bcast) *bcast = 0;
 
@@ -1810,18 +1819,23 @@ static int convert_in_un_remote(struct socket_info *si, const struct sockaddr *i
                return -1;
        }
 
+       swrap_dir = socket_wrapper_dir();
+
        if (is_bcast) {
-               snprintf(un->sun_path, sizeof(un->sun_path), "%s/EINVAL",
-                        socket_wrapper_dir());
+               snprintf(un->sun_path, sizeof(un->sun_path),
+                        "%s/EINVAL", swrap_dir);
                SWRAP_LOG(SWRAP_LOG_DEBUG, "un path [%s]", un->sun_path);
+               SAFE_FREE(swrap_dir);
                /* the caller need to do more processing */
                return 0;
        }
 
        snprintf(un->sun_path, sizeof(un->sun_path), "%s/"SOCKET_FORMAT,
-                socket_wrapper_dir(), type, iface, prt);
+                swrap_dir, type, iface, prt);
        SWRAP_LOG(SWRAP_LOG_DEBUG, "un path [%s]", un->sun_path);
 
+       SAFE_FREE(swrap_dir);
+
        return 0;
 }
 
@@ -1833,6 +1847,7 @@ static int convert_in_un_alloc(struct socket_info *si, const struct sockaddr *in
        unsigned int iface;
        struct stat st;
        int is_bcast = 0;
+       char *swrap_dir = NULL;
 
        if (bcast) *bcast = 0;
 
@@ -1974,11 +1989,13 @@ static int convert_in_un_alloc(struct socket_info *si, const struct sockaddr *in
                return -1;
        }
 
+       swrap_dir = socket_wrapper_dir();
+
        if (prt == 0) {
                /* handle auto-allocation of ephemeral ports */
                for (prt = 5001; prt < 10000; prt++) {
                        snprintf(un->sun_path, sizeof(un->sun_path), "%s/"SOCKET_FORMAT,
-                                socket_wrapper_dir(), type, iface, prt);
+                                swrap_dir, type, iface, prt);
                        if (stat(un->sun_path, &st) == 0) continue;
 
                        set_port(si->family, prt, &si->myname);
@@ -1986,15 +2003,20 @@ static int convert_in_un_alloc(struct socket_info *si, const struct sockaddr *in
 
                        break;
                }
+
                if (prt == 10000) {
                        errno = ENFILE;
+                       SAFE_FREE(swrap_dir);
                        return -1;
                }
        }
 
        snprintf(un->sun_path, sizeof(un->sun_path), "%s/"SOCKET_FORMAT,
-                socket_wrapper_dir(), type, iface, prt);
+                swrap_dir, type, iface, prt);
        SWRAP_LOG(SWRAP_LOG_DEBUG, "un path [%s]", un->sun_path);
+
+       SAFE_FREE(swrap_dir);
+
        return 0;
 }
 
@@ -3456,6 +3478,7 @@ static int swrap_auto_bind(int fd, struct socket_info *si, int family)
        int ret;
        int port;
        struct stat st;
+       char *swrap_dir = NULL;
 
        swrap_mutex_lock(&autobind_start_mutex);
 
@@ -3541,11 +3564,13 @@ static int swrap_auto_bind(int fd, struct socket_info *si, int family)
                autobind_start = 10000;
        }
 
+       swrap_dir = socket_wrapper_dir();
+
        for (i = 0; i < SOCKET_MAX_SOCKETS; i++) {
                port = autobind_start + i;
                snprintf(un_addr.sa.un.sun_path, sizeof(un_addr.sa.un.sun_path),
-                        "%s/"SOCKET_FORMAT, socket_wrapper_dir(),
-                        type, socket_wrapper_default_iface(), port);
+                        "%s/"SOCKET_FORMAT, swrap_dir, type,
+                        socket_wrapper_default_iface(), port);
                if (stat(un_addr.sa.un.sun_path, &st) == 0) continue;
 
                ret = libc_bind(fd, &un_addr.sa.s, un_addr.sa_socklen);
@@ -3577,6 +3602,7 @@ static int swrap_auto_bind(int fd, struct socket_info *si, int family)
        ret = 0;
 
 done:
+       SAFE_FREE(swrap_dir);
        swrap_mutex_unlock(&autobind_start_mutex);
        return ret;
 }
@@ -5339,14 +5365,16 @@ static ssize_t swrap_sendto(int s, const void *buf, size_t len, int flags,
                unsigned int iface;
                unsigned int prt = ntohs(((const struct sockaddr_in *)(const void *)to)->sin_port);
                char type;
+               char *swrap_dir = NULL;
 
                type = SOCKET_TYPE_CHAR_UDP;
 
+               swrap_dir = socket_wrapper_dir();
+
                for(iface=0; iface <= MAX_WRAPPED_INTERFACES; iface++) {
                        snprintf(un_addr.sa.un.sun_path,
                                 sizeof(un_addr.sa.un.sun_path),
-                                "%s/"SOCKET_FORMAT,
-                                socket_wrapper_dir(), type, iface, prt);
+                                "%s/"SOCKET_FORMAT, swrap_dir, type, iface, prt);
                        if (stat(un_addr.sa.un.sun_path, &st) != 0) continue;
 
                        /* ignore the any errors in broadcast sends */
@@ -5358,6 +5386,8 @@ static ssize_t swrap_sendto(int s, const void *buf, size_t len, int flags,
                                    un_addr.sa_socklen);
                }
 
+               SAFE_FREE(swrap_dir);
+
                SWRAP_LOCK_SI(si);
 
                swrap_pcap_dump_packet(si, to, SWRAP_SENDTO, buf, len);
@@ -5818,6 +5848,7 @@ static ssize_t swrap_sendmsg(int s, const struct msghdr *omsg, int flags)
                off_t ofs = 0;
                size_t avail = 0;
                size_t remain;
+               char *swrap_dir = NULL;
 
                for (i = 0; i < (size_t)msg.msg_iovlen; i++) {
                        avail += msg.msg_iov[i].iov_len;
@@ -5843,9 +5874,11 @@ static ssize_t swrap_sendmsg(int s, const struct msghdr *omsg, int flags)
 
                type = SOCKET_TYPE_CHAR_UDP;
 
+               swrap_dir = socket_wrapper_dir();
+
                for(iface=0; iface <= MAX_WRAPPED_INTERFACES; iface++) {
                        snprintf(un_addr.sun_path, sizeof(un_addr.sun_path), "%s/"SOCKET_FORMAT,
-                                socket_wrapper_dir(), type, iface, prt);
+                                swrap_dir, type, iface, prt);
                        if (stat(un_addr.sun_path, &st) != 0) continue;
 
                        msg.msg_name = &un_addr;           /* optional address */
@@ -5855,6 +5888,8 @@ static ssize_t swrap_sendmsg(int s, const struct msghdr *omsg, int flags)
                        libc_sendmsg(s, &msg, flags);
                }
 
+               SAFE_FREE(swrap_dir);
+
                SWRAP_LOCK_SI(si);
 
                swrap_pcap_dump_packet(si, to, SWRAP_SENDTO, buf, len);