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Unverified Commit 19bfd55a by Christian Brauner
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nl: improve how we surface errors

Closes #3057. Signed-off-by: 's avatarChristian Brauner <christian.brauner@ubuntu.com>
parent a5f5cb41
Showing with 61 additions and 78 deletions
src/lxc/nl.c
...@@ -19,16 +19,19 @@ ...@@ -19,16 +19,19 @@
lxc_log_define(nl, lxc); lxc_log_define(nl, lxc);
extern size_t nlmsg_len(const struct nlmsg *nlmsg) size_t nlmsg_len(const struct nlmsg *nlmsg)
{ {
return nlmsg->nlmsghdr->nlmsg_len - NLMSG_HDRLEN; return nlmsg->nlmsghdr->nlmsg_len - NLMSG_HDRLEN;
} }
extern void *nlmsg_data(struct nlmsg *nlmsg) void *nlmsg_data(struct nlmsg *nlmsg)
{ {
char *data = ((char *)nlmsg) + NLMSG_HDRLEN; char *data;
data = ((char *)nlmsg) + NLMSG_HDRLEN;
if (!nlmsg_len(nlmsg)) if (!nlmsg_len(nlmsg))
return NULL; return ret_set_errno(NULL, EINVAL);
return data; return data;
} }
...@@ -40,7 +43,7 @@ static int nla_put(struct nlmsg *nlmsg, int attr, ...@@ -40,7 +43,7 @@ static int nla_put(struct nlmsg *nlmsg, int attr,
size_t tlen = NLMSG_ALIGN(nlmsg->nlmsghdr->nlmsg_len) + RTA_ALIGN(rtalen); size_t tlen = NLMSG_ALIGN(nlmsg->nlmsghdr->nlmsg_len) + RTA_ALIGN(rtalen);
if (tlen > nlmsg->cap) if (tlen > nlmsg->cap)
return -ENOMEM; return ret_errno(ENOMEM);
rta = NLMSG_TAIL(nlmsg->nlmsghdr); rta = NLMSG_TAIL(nlmsg->nlmsghdr);
rta->rta_type = attr; rta->rta_type = attr;
...@@ -48,41 +51,42 @@ static int nla_put(struct nlmsg *nlmsg, int attr, ...@@ -48,41 +51,42 @@ static int nla_put(struct nlmsg *nlmsg, int attr,
if (data && len) if (data && len)
memcpy(RTA_DATA(rta), data, len); memcpy(RTA_DATA(rta), data, len);
nlmsg->nlmsghdr->nlmsg_len = tlen; nlmsg->nlmsghdr->nlmsg_len = tlen;
return 0; return 0;
} }
extern int nla_put_buffer(struct nlmsg *nlmsg, int attr, int nla_put_buffer(struct nlmsg *nlmsg, int attr, const void *data, size_t size)
const void *data, size_t size)
{ {
return nla_put(nlmsg, attr, data, size); return nla_put(nlmsg, attr, data, size);
} }
extern int nla_put_string(struct nlmsg *nlmsg, int attr, const char *string) int nla_put_string(struct nlmsg *nlmsg, int attr, const char *string)
{ {
return nla_put(nlmsg, attr, string, strlen(string) + 1); return nla_put(nlmsg, attr, string, strlen(string) + 1);
} }
extern int nla_put_u32(struct nlmsg *nlmsg, int attr, int value) int nla_put_u32(struct nlmsg *nlmsg, int attr, int value)
{ {
return nla_put(nlmsg, attr, &value, sizeof(value)); return nla_put(nlmsg, attr, &value, sizeof(value));
} }
extern int nla_put_u16(struct nlmsg *nlmsg, int attr, unsigned short value) int nla_put_u16(struct nlmsg *nlmsg, int attr, unsigned short value)
{ {
return nla_put(nlmsg, attr, &value, 2); return nla_put(nlmsg, attr, &value, 2);
} }
extern int nla_put_attr(struct nlmsg *nlmsg, int attr) int nla_put_attr(struct nlmsg *nlmsg, int attr)
{ {
return nla_put(nlmsg, attr, NULL, 0); return nla_put(nlmsg, attr, NULL, 0);
} }
struct rtattr *nla_begin_nested(struct nlmsg *nlmsg, int attr) struct rtattr *nla_begin_nested(struct nlmsg *nlmsg, int attr)
{ {
struct rtattr *rtattr = NLMSG_TAIL(nlmsg->nlmsghdr); struct rtattr *rtattr;
rtattr = NLMSG_TAIL(nlmsg->nlmsghdr);
if (nla_put_attr(nlmsg, attr)) if (nla_put_attr(nlmsg, attr))
return NULL; return ret_set_errno(NULL, ENOMEM);
return rtattr; return rtattr;
} }
...@@ -92,37 +96,34 @@ void nla_end_nested(struct nlmsg *nlmsg, struct rtattr *attr) ...@@ -92,37 +96,34 @@ void nla_end_nested(struct nlmsg *nlmsg, struct rtattr *attr)
attr->rta_len = (void *)NLMSG_TAIL(nlmsg->nlmsghdr) - (void *)attr; attr->rta_len = (void *)NLMSG_TAIL(nlmsg->nlmsghdr) - (void *)attr;
} }
extern struct nlmsg *nlmsg_alloc(size_t size) struct nlmsg *nlmsg_alloc(size_t size)
{ {
struct nlmsg *nlmsg; __do_free struct nlmsg *nlmsg = NULL;
size_t len = NLMSG_HDRLEN + NLMSG_ALIGN(size); size_t len = NLMSG_HDRLEN + NLMSG_ALIGN(size);
nlmsg = (struct nlmsg *)malloc(sizeof(struct nlmsg)); nlmsg = malloc(sizeof(struct nlmsg));
if (!nlmsg) if (!nlmsg)
return NULL; return ret_set_errno(NULL, ENOMEM);
nlmsg->nlmsghdr = (struct nlmsghdr *)malloc(len); nlmsg->nlmsghdr = malloc(len);
if (!nlmsg->nlmsghdr) if (!nlmsg->nlmsghdr)
goto errout; return ret_set_errno(NULL, ENOMEM);
memset(nlmsg->nlmsghdr, 0, len); memset(nlmsg->nlmsghdr, 0, len);
nlmsg->cap = len; nlmsg->cap = len;
nlmsg->nlmsghdr->nlmsg_len = NLMSG_HDRLEN; nlmsg->nlmsghdr->nlmsg_len = NLMSG_HDRLEN;
return nlmsg; return move_ptr(nlmsg);
errout:
free(nlmsg);
return NULL;
} }
extern void *nlmsg_reserve(struct nlmsg *nlmsg, size_t len) void *nlmsg_reserve(struct nlmsg *nlmsg, size_t len)
{ {
void *buf; void *buf;
size_t nlmsg_len = nlmsg->nlmsghdr->nlmsg_len; size_t nlmsg_len = nlmsg->nlmsghdr->nlmsg_len;
size_t tlen = NLMSG_ALIGN(len); size_t tlen = NLMSG_ALIGN(len);
if (nlmsg_len + tlen > nlmsg->cap) if (nlmsg_len + tlen > nlmsg->cap)
return NULL; return ret_set_errno(NULL, ENOMEM);
buf = ((char *)(nlmsg->nlmsghdr)) + nlmsg_len; buf = ((char *)(nlmsg->nlmsghdr)) + nlmsg_len;
nlmsg->nlmsghdr->nlmsg_len += tlen; nlmsg->nlmsghdr->nlmsg_len += tlen;
...@@ -133,29 +134,28 @@ extern void *nlmsg_reserve(struct nlmsg *nlmsg, size_t len) ...@@ -133,29 +134,28 @@ extern void *nlmsg_reserve(struct nlmsg *nlmsg, size_t len)
return buf; return buf;
} }
extern struct nlmsg *nlmsg_alloc_reserve(size_t size) struct nlmsg *nlmsg_alloc_reserve(size_t size)
{ {
struct nlmsg *nlmsg; struct nlmsg *nlmsg;
nlmsg = nlmsg_alloc(size); nlmsg = nlmsg_alloc(size);
if (!nlmsg) if (!nlmsg)
return NULL; return ret_set_errno(NULL, ENOMEM);
/* Just set message length to cap directly. */ /* Just set message length to cap directly. */
nlmsg->nlmsghdr->nlmsg_len = nlmsg->cap; nlmsg->nlmsghdr->nlmsg_len = nlmsg->cap;
return nlmsg; return nlmsg;
} }
extern void nlmsg_free(struct nlmsg *nlmsg) void nlmsg_free(struct nlmsg *nlmsg)
{ {
if (!nlmsg) if (nlmsg) {
return;
free(nlmsg->nlmsghdr); free(nlmsg->nlmsghdr);
free(nlmsg); free(nlmsg);
}
} }
extern int __netlink_recv(struct nl_handler *handler, struct nlmsghdr *nlmsghdr) int __netlink_recv(struct nl_handler *handler, struct nlmsghdr *nlmsghdr)
{ {
int ret; int ret;
struct sockaddr_nl nladdr; struct sockaddr_nl nladdr;
...@@ -182,26 +182,24 @@ again: ...@@ -182,26 +182,24 @@ again:
if (errno == EINTR) if (errno == EINTR)
goto again; goto again;
return -1; return ret_errno(errno);
} }
if (!ret) if (!ret)
return 0; return 0;
if (msg.msg_flags & MSG_TRUNC && (ret == nlmsghdr->nlmsg_len)) { if (msg.msg_flags & MSG_TRUNC && (ret == nlmsghdr->nlmsg_len))
errno = EMSGSIZE; return ret_errno(EMSGSIZE);
ret = -1;
}
return ret; return ret;
} }
extern int netlink_rcv(struct nl_handler *handler, struct nlmsg *answer) int netlink_rcv(struct nl_handler *handler, struct nlmsg *answer)
{ {
return __netlink_recv(handler, answer->nlmsghdr); return __netlink_recv(handler, answer->nlmsghdr);
} }
extern int __netlink_send(struct nl_handler *handler, struct nlmsghdr *nlmsghdr) int __netlink_send(struct nl_handler *handler, struct nlmsghdr *nlmsghdr)
{ {
int ret; int ret;
struct sockaddr_nl nladdr; struct sockaddr_nl nladdr;
...@@ -223,7 +221,7 @@ extern int __netlink_send(struct nl_handler *handler, struct nlmsghdr *nlmsghdr) ...@@ -223,7 +221,7 @@ extern int __netlink_send(struct nl_handler *handler, struct nlmsghdr *nlmsghdr)
ret = sendmsg(handler->fd, &msg, MSG_NOSIGNAL); ret = sendmsg(handler->fd, &msg, MSG_NOSIGNAL);
if (ret < 0) if (ret < 0)
return -1; return ret_errno(errno);
return ret; return ret;
} }
...@@ -241,21 +239,19 @@ extern int __netlink_transaction(struct nl_handler *handler, ...@@ -241,21 +239,19 @@ extern int __netlink_transaction(struct nl_handler *handler,
ret = __netlink_send(handler, request); ret = __netlink_send(handler, request);
if (ret < 0) if (ret < 0)
return -1; return ret;
ret = __netlink_recv(handler, answer); ret = __netlink_recv(handler, answer);
if (ret < 0) if (ret < 0)
return -1; return ret;
ret = 0;
if (answer->nlmsg_type == NLMSG_ERROR) { if (answer->nlmsg_type == NLMSG_ERROR) {
struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(answer); struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(answer);
errno = -err->error;
if (err->error < 0) if (err->error < 0)
ret = -1; return ret_errno(-err->error);
} }
return ret; return 0;
} }
extern int netlink_transaction(struct nl_handler *handler, extern int netlink_transaction(struct nl_handler *handler,
...@@ -267,56 +263,44 @@ extern int netlink_transaction(struct nl_handler *handler, ...@@ -267,56 +263,44 @@ extern int netlink_transaction(struct nl_handler *handler,
extern int netlink_open(struct nl_handler *handler, int protocol) extern int netlink_open(struct nl_handler *handler, int protocol)
{ {
__do_close int fd = -EBADF;
socklen_t socklen; socklen_t socklen;
int sndbuf = 32768; int sndbuf = 32768;
int rcvbuf = 32768; int rcvbuf = 32768;
int err;
memset(handler, 0, sizeof(*handler)); memset(handler, 0, sizeof(*handler));
handler->fd = -EBADF;
handler->fd = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, protocol); fd = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, protocol);
if (handler->fd < 0) if (fd < 0)
return -errno; return ret_errno(errno);
if (setsockopt(handler->fd, SOL_SOCKET, SO_SNDBUF, if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &sndbuf, sizeof(sndbuf)) < 0)
&sndbuf, sizeof(sndbuf)) < 0) return ret_errno(errno);
goto err_with_errno;
if (setsockopt(handler->fd, SOL_SOCKET, SO_RCVBUF, if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &rcvbuf,sizeof(rcvbuf)) < 0)
&rcvbuf,sizeof(rcvbuf)) < 0) return ret_errno(errno);
goto err_with_errno;
memset(&handler->local, 0, sizeof(handler->local)); memset(&handler->local, 0, sizeof(handler->local));
handler->local.nl_family = AF_NETLINK; handler->local.nl_family = AF_NETLINK;
handler->local.nl_groups = 0; handler->local.nl_groups = 0;
if (bind(handler->fd, (struct sockaddr*)&handler->local, if (bind(fd, (struct sockaddr*)&handler->local, sizeof(handler->local)) < 0)
sizeof(handler->local)) < 0) return ret_errno(errno);
goto err_with_errno;
socklen = sizeof(handler->local); socklen = sizeof(handler->local);
if (getsockname(handler->fd, (struct sockaddr*)&handler->local, if (getsockname(fd, (struct sockaddr*)&handler->local, &socklen) < 0)
&socklen) < 0) return ret_errno(errno);
goto err_with_errno;
if (socklen != sizeof(handler->local)) { if (socklen != sizeof(handler->local))
err = -EINVAL; return ret_errno(EINVAL);
goto errclose;
}
if (handler->local.nl_family != AF_NETLINK) { if (handler->local.nl_family != AF_NETLINK)
err = -EINVAL; return ret_errno(EINVAL);
goto errclose;
}
handler->seq = time(NULL); handler->seq = time(NULL);
handler->fd = move_fd(fd);
return 0; return 0;
err_with_errno:
err = -errno;
errclose:
close(handler->fd);
return err;
} }
extern void netlink_close(struct nl_handler *handler) extern void netlink_close(struct nl_handler *handler)
...@@ -330,9 +314,8 @@ int addattr(struct nlmsghdr *n, size_t maxlen, int type, const void *data, ...@@ -330,9 +314,8 @@ int addattr(struct nlmsghdr *n, size_t maxlen, int type, const void *data,
int len = RTA_LENGTH(alen); int len = RTA_LENGTH(alen);
struct rtattr *rta; struct rtattr *rta;
errno = EMSGSIZE;
if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen)
return -1; return ret_errno(EMSGSIZE);
rta = NLMSG_TAIL(n); rta = NLMSG_TAIL(n);
rta->rta_type = type; rta->rta_type = type;
......
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