inet: fix: possible unaligned access in packed structure (inet/inet6)

Fix the warnings that unaligned pointers can be passed as parameters
emitted when building inet.c and inet6.c.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/common/macros.h b/src/common/macros.h
index 13f51d9d1cb4d6fe7c3191e6a59e94b9a57643bd..36ec04b745738d59090f2de5825ba230060b9fa4 100644 (file)
--- a/src/common/macros.h
+++ b/src/common/macros.h
@@ -96,6 +96,13 @@ void *zmalloc(size_t len)
 
 #define member_sizeof(type, field)     sizeof(((type *) 0)->field)
 
+/*
+ * Get an aligned pointer to a value. This is meant
+ * as a helper to pass an aligned pointer to a member in a packed structure
+ * to a function.
+ */
+#define ALIGNED_CONST_PTR(value) (((const typeof(value) []) { value }))
+
 /*
  * lttng_strncpy returns 0 on success, or nonzero on failure.
  * It checks that the @src string fits into @dst_len before performing

diff --git a/src/common/sessiond-comm/inet.c b/src/common/sessiond-comm/inet.c
index bda46a82f3e8ec7596a48d7fdc07bf641bd154b1..f7e4908a9382b14acc232f228ea0a63a271e39b7 100644 (file)
--- a/src/common/sessiond-comm/inet.c
+++ b/src/common/sessiond-comm/inet.c
@@ -101,14 +101,17 @@ LTTNG_HIDDEN
 int lttcomm_bind_inet_sock(struct lttcomm_sock *sock)
 {
        return bind(sock->fd,
-                       (const struct sockaddr *) &sock->sockaddr.addr.sin,
+                       (const struct sockaddr *) ALIGNED_CONST_PTR(
+                                       sock->sockaddr.addr.sin),
                        sizeof(sock->sockaddr.addr.sin));
 }
 
 static
 int connect_no_timeout(struct lttcomm_sock *sock)
 {
-       return connect(sock->fd, (struct sockaddr *) &sock->sockaddr.addr.sin,
+       return connect(sock->fd,
+                       (const struct sockaddr *) ALIGNED_CONST_PTR(
+                                       sock->sockaddr.addr.sin),
                        sizeof(sock->sockaddr.addr.sin));
 }
 
@@ -141,11 +144,11 @@ int connect_with_timeout(struct lttcomm_sock *sock)
        }
 
        connect_ret = connect(sock->fd,
-               (struct sockaddr *) &sock->sockaddr.addr.sin,
-               sizeof(sock->sockaddr.addr.sin));
-       if (connect_ret == -1 && errno != EAGAIN
-                       && errno != EWOULDBLOCK
-                       && errno != EINPROGRESS) {
+                       (const struct sockaddr *) ALIGNED_CONST_PTR(
+                                       sock->sockaddr.addr.sin),
+                       sizeof(sock->sockaddr.addr.sin));
+       if (connect_ret == -1 && errno != EAGAIN && errno != EWOULDBLOCK &&
+                       errno != EINPROGRESS) {
                goto error;
        } else if (!connect_ret) {
                /* Connect succeeded */
@@ -261,6 +264,7 @@ struct lttcomm_sock *lttcomm_accept_inet_sock(struct lttcomm_sock *sock)
        socklen_t len;
        struct lttcomm_sock *new_sock;
        unsigned long timeout;
+       struct sockaddr_in new_addr = {};
 
        if (sock->proto == LTTCOMM_SOCK_UDP) {
                /*
@@ -275,15 +279,15 @@ struct lttcomm_sock *lttcomm_accept_inet_sock(struct lttcomm_sock *sock)
                goto error;
        }
 
-       len = sizeof(new_sock->sockaddr.addr.sin);
+       len = sizeof(new_addr);
 
        /* Blocking call */
-       new_fd = accept(sock->fd, (struct sockaddr *) &new_sock->sockaddr.addr.sin,
-                       &len);
+       new_fd = accept(sock->fd, (struct sockaddr *) &new_addr, &len);
        if (new_fd < 0) {
                PERROR("accept inet");
                goto error;
        }
+       new_sock->sockaddr.addr.sin = new_addr;
        timeout = lttcomm_get_network_timeout();
        if (timeout) {
                int ret;
@@ -356,6 +360,7 @@ ssize_t lttcomm_recvmsg_inet_sock(struct lttcomm_sock *sock, void *buf,
        struct iovec iov[1];
        ssize_t ret = -1;
        size_t len_last;
+       struct sockaddr_in addr = sock->sockaddr.addr.sin;
 
        memset(&msg, 0, sizeof(msg));
 
@@ -364,7 +369,7 @@ ssize_t lttcomm_recvmsg_inet_sock(struct lttcomm_sock *sock, void *buf,
        msg.msg_iov = iov;
        msg.msg_iovlen = 1;
 
-       msg.msg_name = (struct sockaddr *) &sock->sockaddr.addr.sin;
+       msg.msg_name = (struct sockaddr *) &addr;
        msg.msg_namelen = sizeof(sock->sockaddr.addr.sin);
 
        do {
@@ -408,9 +413,13 @@ ssize_t lttcomm_sendmsg_inet_sock(struct lttcomm_sock *sock, const void *buf,
 
        switch (sock->proto) {
        case LTTCOMM_SOCK_UDP:
-               msg.msg_name = (struct sockaddr *) &sock->sockaddr.addr.sin;
+       {
+               struct sockaddr_in addr = sock->sockaddr.addr.sin;
+
+               msg.msg_name = (struct sockaddr *) &addr;
                msg.msg_namelen = sizeof(sock->sockaddr.addr.sin);
                break;
+       }
        default:
                break;
        }

diff --git a/src/common/sessiond-comm/inet6.c b/src/common/sessiond-comm/inet6.c
index a96fb7b88683778f60e926907cc496ea84164a02..b128b86f0012733fae53e0d32cb0f96388986da6 100644 (file)
--- a/src/common/sessiond-comm/inet6.c
+++ b/src/common/sessiond-comm/inet6.c
@@ -99,14 +99,17 @@ LTTNG_HIDDEN
 int lttcomm_bind_inet6_sock(struct lttcomm_sock *sock)
 {
        return bind(sock->fd,
-                       (const struct sockaddr *) &sock->sockaddr.addr.sin6,
+                       (const struct sockaddr *) ALIGNED_CONST_PTR(
+                                       sock->sockaddr.addr.sin6),
                        sizeof(sock->sockaddr.addr.sin6));
 }
 
 static
 int connect_no_timeout(struct lttcomm_sock *sock)
 {
-       return connect(sock->fd, (struct sockaddr *) &sock->sockaddr.addr.sin6,
+       return connect(sock->fd,
+                       (const struct sockaddr *) ALIGNED_CONST_PTR(
+                                       sock->sockaddr.addr.sin6),
                        sizeof(sock->sockaddr.addr.sin6));
 }
 
@@ -139,11 +142,11 @@ int connect_with_timeout(struct lttcomm_sock *sock)
        }
 
        connect_ret = connect(sock->fd,
-               (struct sockaddr *) &sock->sockaddr.addr.sin6,
-               sizeof(sock->sockaddr.addr.sin6));
-       if (connect_ret == -1 && errno != EAGAIN
-                       && errno != EWOULDBLOCK
-                       && errno != EINPROGRESS) {
+                       (const struct sockaddr *) ALIGNED_CONST_PTR(
+                                       sock->sockaddr.addr.sin6),
+                       sizeof(sock->sockaddr.addr.sin6));
+       if (connect_ret == -1 && errno != EAGAIN && errno != EWOULDBLOCK &&
+                       errno != EINPROGRESS) {
                goto error;
        } else if (!connect_ret) {
                /* Connect succeeded */
@@ -259,6 +262,7 @@ struct lttcomm_sock *lttcomm_accept_inet6_sock(struct lttcomm_sock *sock)
        int new_fd;
        socklen_t len;
        struct lttcomm_sock *new_sock;
+       struct sockaddr_in6 new_addr = {};
 
        if (sock->proto == LTTCOMM_SOCK_UDP) {
                /*
@@ -273,16 +277,15 @@ struct lttcomm_sock *lttcomm_accept_inet6_sock(struct lttcomm_sock *sock)
                goto error;
        }
 
-       len = sizeof(new_sock->sockaddr.addr.sin6);
+       len = sizeof(new_addr);
 
        /* Blocking call */
-       new_fd = accept(sock->fd,
-                       (struct sockaddr *) &new_sock->sockaddr.addr.sin6, &len);
+       new_fd = accept(sock->fd, (struct sockaddr *) &new_addr, &len);
        if (new_fd < 0) {
                PERROR("accept inet6");
                goto error;
        }
-
+       new_sock->sockaddr.addr.sin6 = new_addr;
        new_sock->fd = new_fd;
        new_sock->ops = &inet6_ops;
 
@@ -336,6 +339,7 @@ ssize_t lttcomm_recvmsg_inet6_sock(struct lttcomm_sock *sock, void *buf,
        struct iovec iov[1];
        ssize_t ret = -1;
        size_t len_last;
+       struct sockaddr_in6 addr = sock->sockaddr.addr.sin6;
 
        memset(&msg, 0, sizeof(msg));
 
@@ -344,7 +348,7 @@ ssize_t lttcomm_recvmsg_inet6_sock(struct lttcomm_sock *sock, void *buf,
        msg.msg_iov = iov;
        msg.msg_iovlen = 1;
 
-       msg.msg_name = (struct sockaddr *) &sock->sockaddr.addr.sin6;
+       msg.msg_name = (struct sockaddr *) &addr;
        msg.msg_namelen = sizeof(sock->sockaddr.addr.sin6);
 
        do {
@@ -388,9 +392,13 @@ ssize_t lttcomm_sendmsg_inet6_sock(struct lttcomm_sock *sock, const void *buf,
 
        switch (sock->proto) {
        case LTTCOMM_SOCK_UDP:
-               msg.msg_name = (struct sockaddr *) &sock->sockaddr.addr.sin6;
+       {
+               struct sockaddr_in6 addr = sock->sockaddr.addr.sin6;
+
+               msg.msg_name = (struct sockaddr *) &addr;
                msg.msg_namelen = sizeof(sock->sockaddr.addr.sin6);
                break;
+       }
        default:
                break;
        }