af_unix: remove unlink operation

[mirror_lxc.git] / src / lxc / af_unix.c

diff --git a/src/lxc/af_unix.c b/src/lxc/af_unix.c
index 46d8e50fc3aac68f4c50bfe35fd38bdeb1f33c43..be7f6ce597b0932b6cfcde2544286a4d82bc21e9 100644 (file)
--- a/src/lxc/af_unix.c
+++ b/src/lxc/af_unix.c
@@ -22,6 +22,8 @@
  */
 #include "config.h"
 
+#include <stdio.h>
+#include <stdlib.h>
 #include <stddef.h>
 #include <string.h>
 #include <unistd.h>
@@ -40,9 +42,6 @@ int lxc_abstract_unix_open(const char *path, int type, int flags)
        size_t len;
        struct sockaddr_un addr;
 
-       if (flags & O_TRUNC)
-               unlink(path);
-
        fd = socket(PF_UNIX, type, 0);
        if (fd < 0)
                return -1;
@@ -55,8 +54,9 @@ int lxc_abstract_unix_open(const char *path, int type, int flags)
 
        addr.sun_family = AF_UNIX;
 
-       len = strlen(&path[1]) + 1;
-       if (len >= sizeof(addr.sun_path) - 1) {
+       len = strlen(&path[1]);
+       /* do not enforce \0-termination */
+       if (len >= sizeof(addr.sun_path)) {
                close(fd);
                errno = ENAMETOOLONG;
                return -1;
@@ -64,7 +64,7 @@ int lxc_abstract_unix_open(const char *path, int type, int flags)
        /* addr.sun_path[0] has already been set to 0 by memset() */
        strncpy(&addr.sun_path[1], &path[1], strlen(&path[1]));
 
-       if (bind(fd, (struct sockaddr *)&addr, offsetof(struct sockaddr_un, sun_path) + len)) {
+       if (bind(fd, (struct sockaddr *)&addr, offsetof(struct sockaddr_un, sun_path) + len + 1)) {
                int tmp = errno;
                close(fd);
                errno = tmp;
@@ -83,13 +83,6 @@ int lxc_abstract_unix_open(const char *path, int type, int flags)
 
 int lxc_abstract_unix_close(int fd)
 {
-       struct sockaddr_un addr;
-       socklen_t addrlen = sizeof(addr);
-
-       if (!getsockname(fd, (struct sockaddr *)&addr, &addrlen) &&
-                       addr.sun_path[0])
-               unlink(addr.sun_path);
-
        close(fd);
 
        return 0;
@@ -109,8 +102,9 @@ int lxc_abstract_unix_connect(const char *path)
 
        addr.sun_family = AF_UNIX;
 
-       len = strlen(&path[1]) + 1;
-       if (len >= sizeof(addr.sun_path) - 1) {
+       len = strlen(&path[1]);
+       /* do not enforce \0-termination */
+       if (len >= sizeof(addr.sun_path)) {
                close(fd);
                errno = ENAMETOOLONG;
                return -1;
@@ -118,7 +112,7 @@ int lxc_abstract_unix_connect(const char *path)
        /* addr.sun_path[0] has already been set to 0 by memset() */
        strncpy(&addr.sun_path[1], &path[1], strlen(&path[1]));
 
-       if (connect(fd, (struct sockaddr *)&addr, offsetof(struct sockaddr_un, sun_path) + len)) {
+       if (connect(fd, (struct sockaddr *)&addr, offsetof(struct sockaddr_un, sun_path) + len + 1)) {
                int tmp = errno;
                /* special case to connect to older containers */
                if (connect(fd, (struct sockaddr *)&addr, sizeof(addr)) == 0)
@@ -131,49 +125,66 @@ int lxc_abstract_unix_connect(const char *path)
        return fd;
 }
 
-int lxc_abstract_unix_send_fd(int fd, int sendfd, void *data, size_t size)
+int lxc_abstract_unix_send_fds(int fd, int *sendfds, int num_sendfds,
+                              void *data, size_t size)
 {
-       struct msghdr msg = { 0 };
+       int ret;
+       struct msghdr msg;
        struct iovec iov;
-       struct cmsghdr *cmsg;
-       char cmsgbuf[CMSG_SPACE(sizeof(int))];
-       char buf[1];
-       int *val;
+       struct cmsghdr *cmsg = NULL;
+       char buf[1] = {0};
+       char *cmsgbuf;
+       size_t cmsgbufsize = CMSG_SPACE(num_sendfds * sizeof(int));
+
+       memset(&msg, 0, sizeof(msg));
+       memset(&iov, 0, sizeof(iov));
+
+       cmsgbuf = malloc(cmsgbufsize);
+       if (!cmsgbuf)
+               return -1;
 
        msg.msg_control = cmsgbuf;
-       msg.msg_controllen = sizeof(cmsgbuf);
+       msg.msg_controllen = cmsgbufsize;
 
        cmsg = CMSG_FIRSTHDR(&msg);
-       cmsg->cmsg_len = CMSG_LEN(sizeof(int));
        cmsg->cmsg_level = SOL_SOCKET;
        cmsg->cmsg_type = SCM_RIGHTS;
-       val = (int *)(CMSG_DATA(cmsg));
-       *val = sendfd;
+       cmsg->cmsg_len = CMSG_LEN(num_sendfds * sizeof(int));
 
-       msg.msg_name = NULL;
-       msg.msg_namelen = 0;
+       msg.msg_controllen = cmsg->cmsg_len;
+
+       memcpy(CMSG_DATA(cmsg), sendfds, num_sendfds * sizeof(int));
 
        iov.iov_base = data ? data : buf;
        iov.iov_len = data ? size : sizeof(buf);
        msg.msg_iov = &iov;
        msg.msg_iovlen = 1;
 
-       return sendmsg(fd, &msg, MSG_NOSIGNAL);
+       ret = sendmsg(fd, &msg, MSG_NOSIGNAL);
+       free(cmsgbuf);
+       return ret;
 }
 
-int lxc_abstract_unix_recv_fd(int fd, int *recvfd, void *data, size_t size)
+int lxc_abstract_unix_recv_fds(int fd, int *recvfds, int num_recvfds,
+                              void *data, size_t size)
 {
-       struct msghdr msg = { 0 };
+       int ret;
+       struct msghdr msg;
        struct iovec iov;
-       struct cmsghdr *cmsg;
-       char cmsgbuf[CMSG_SPACE(sizeof(int))];
-       char buf[1];
-       int ret, *val;
+       struct cmsghdr *cmsg = NULL;
+       char buf[1] = {0};
+       char *cmsgbuf;
+       size_t cmsgbufsize = CMSG_SPACE(num_recvfds * sizeof(int));
+
+       memset(&msg, 0, sizeof(msg));
+       memset(&iov, 0, sizeof(iov));
+
+       cmsgbuf = malloc(cmsgbufsize);
+       if (!cmsgbuf)
+               return -1;
 
-       msg.msg_name = NULL;
-       msg.msg_namelen = 0;
        msg.msg_control = cmsgbuf;
-       msg.msg_controllen = sizeof(cmsgbuf);
+       msg.msg_controllen = cmsgbufsize;
 
        iov.iov_base = data ? data : buf;
        iov.iov_len = data ? size : sizeof(buf);
@@ -186,17 +197,14 @@ int lxc_abstract_unix_recv_fd(int fd, int *recvfd, void *data, size_t size)
 
        cmsg = CMSG_FIRSTHDR(&msg);
 
-       /* if the message is wrong the variable will not be
-        * filled and the peer will notified about a problem */
-       *recvfd = -1;
-
-       if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(int)) &&
-                       cmsg->cmsg_level == SOL_SOCKET &&
-                       cmsg->cmsg_type == SCM_RIGHTS) {
-               val = (int *) CMSG_DATA(cmsg);
-               *recvfd = *val;
+       memset(recvfds, -1, num_recvfds * sizeof(int));
+       if (cmsg && cmsg->cmsg_len == CMSG_LEN(num_recvfds * sizeof(int)) &&
+           cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
+               memcpy(recvfds, CMSG_DATA(cmsg), num_recvfds * sizeof(int));
        }
+
 out:
+       free(cmsgbuf);
        return ret;
 }
 
@@ -210,8 +218,8 @@ int lxc_abstract_unix_send_credential(int fd, void *data, size_t size)
                .uid = getuid(),
                .gid = getgid(),
        };
-       char cmsgbuf[CMSG_SPACE(sizeof(cred))];
-       char buf[1];
+       char cmsgbuf[CMSG_SPACE(sizeof(cred))] = {0};
+       char buf[1] = {0};
 
        msg.msg_control = cmsgbuf;
        msg.msg_controllen = sizeof(cmsgbuf);
@@ -239,9 +247,9 @@ int lxc_abstract_unix_rcv_credential(int fd, void *data, size_t size)
        struct iovec iov;
        struct cmsghdr *cmsg;
        struct ucred cred;
-       char cmsgbuf[CMSG_SPACE(sizeof(cred))];
-       char buf[1];
        int ret;
+       char cmsgbuf[CMSG_SPACE(sizeof(cred))] = {0};
+       char buf[1] = {0};
 
        msg.msg_name = NULL;
        msg.msg_namelen = 0;