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 9637a383013629baf868dfca60dc15a65da05757..e2d0fcf3eae8e61fd1c7030e5f807e3d1b92bdf6 100644 (file)
--- a/src/common/macros.h
+++ b/src/common/macros.h
@@ -87,6 +87,13 @@ 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 6b7a894ad5e5758b2dc4b89a05a79c58f9270a6e..22d9181eeeb1f4f562e64a314320c6a3f14133ed 100644 (file)
--- a/src/common/sessiond-comm/inet.c
+++ b/src/common/sessiond-comm/inet.c
@@ -102,7 +102,8 @@ int lttcomm_bind_inet_sock(struct lttcomm_sock *sock)
 {
        int ret;
 
-       ret = bind(sock->fd, (const struct sockaddr *) &sock->sockaddr.addr.sin,
+       ret = bind(sock->fd, (const struct sockaddr *) ALIGNED_CONST_PTR(
+                       sock->sockaddr.addr.sin),
                        sizeof(sock->sockaddr.addr.sin));
        if (ret < 0) {
                PERROR("bind inet");
@@ -114,7 +115,9 @@ int lttcomm_bind_inet_sock(struct lttcomm_sock *sock)
 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));
 }
 
@@ -147,11 +150,11 @@ 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 */
@@ -267,6 +270,7 @@ 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) {
                /*
@@ -281,15 +285,15 @@ 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;
@@ -362,6 +366,7 @@ 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));
 
@@ -370,7 +375,7 @@ 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 {
@@ -414,9 +419,13 @@ 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 60fe44f1e68ebbac5784bd8dae3d74e511b19c15..e8c7616036758f53626388060354f0c0416300ef 100644 (file)
--- a/src/common/sessiond-comm/inet6.c
+++ b/src/common/sessiond-comm/inet6.c
@@ -100,7 +100,8 @@ int lttcomm_bind_inet6_sock(struct lttcomm_sock *sock)
 {
        int ret;
 
-       ret = bind(sock->fd, (const struct sockaddr *) &sock->sockaddr.addr.sin6,
+       ret = bind(sock->fd, (const struct sockaddr *) ALIGNED_CONST_PTR(
+                       sock->sockaddr.addr.sin6),
                        sizeof(sock->sockaddr.addr.sin6));
        if (ret < 0) {
                PERROR("bind inet6");
@@ -112,7 +113,9 @@ int lttcomm_bind_inet6_sock(struct lttcomm_sock *sock)
 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));
 }
 
@@ -145,11 +148,11 @@ 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 */
@@ -265,6 +268,7 @@ 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) {
                /*
@@ -279,16 +283,15 @@ 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;
 
@@ -342,6 +345,7 @@ 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));
 
@@ -350,7 +354,7 @@ 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 {
@@ -394,9 +398,13 @@ 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;
        }