bpf_skb_utils.h: add missing include to fix build against newer kernel headers
[project/unetd.git] / pex-msg.c
index 22825be1d552738ad2552455a57d4a26bac61f77..d7581b96e0807957a88a070d186da9ca0d977a9b 100644 (file)
--- a/pex-msg.c
+++ b/pex-msg.c
@@ -4,22 +4,56 @@
  */
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <sys/un.h>
 #include <arpa/inet.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <libubox/list.h>
 #include <libubox/uloop.h>
+#include <libubox/usock.h>
 #include "pex-msg.h"
 #include "chacha20.h"
 #include "auth-data.h"
 
 static char pex_tx_buf[PEX_BUF_SIZE];
 static FILE *pex_urandom;
-static struct uloop_fd pex_fd;
+static struct uloop_fd pex_fd, pex_unix_fd;
 static LIST_HEAD(requests);
 static struct uloop_timeout gc_timer;
+static int pex_raw_v4_fd = -1, pex_raw_v6_fd = -1;
 
 static pex_recv_cb_t pex_recv_cb;
+static pex_recv_control_cb_t pex_control_cb;
+static int pex_unix_tx_fd = -1;
+
+int pex_socket(void)
+{
+       return pex_fd.fd;
+}
+
+int pex_raw_socket(int family)
+{
+       return family == AF_INET ? pex_raw_v4_fd : pex_raw_v6_fd;
+}
+
+static const void *
+get_mapped_sockaddr(const void *addr)
+{
+       static struct sockaddr_in6 sin6;
+       const struct sockaddr_in *sin = addr;
+
+       if (!sin || sin->sin_family != AF_INET)
+               return addr;
+
+       memset(&sin6, 0, sizeof(sin6));
+       sin6.sin6_family = AF_INET6;
+       sin6.sin6_addr.s6_addr[10] = 0xff;
+       sin6.sin6_addr.s6_addr[11] = 0xff;
+       memcpy(&sin6.sin6_addr.s6_addr[12], &sin->sin_addr, sizeof(struct in_addr));
+       sin6.sin6_port = sin->sin_port;
+
+       return &sin6;
+}
 
 struct pex_msg_update_recv_ctx {
        struct list_head list;
@@ -42,8 +76,10 @@ struct pex_msg_update_recv_ctx {
 uint64_t pex_network_hash(const uint8_t *auth_key, uint64_t req_id)
 {
        siphash_key_t key = {
-               be64_to_cpu(req_id),
-               be64_to_cpu(req_id)
+               .key = {
+                       be64_to_cpu(req_id),
+                       be64_to_cpu(req_id)
+               }
        };
        uint64_t hash;
 
@@ -105,12 +141,19 @@ void *pex_msg_append(size_t len)
 static void
 pex_fd_cb(struct uloop_fd *fd, unsigned int events)
 {
-       struct sockaddr_in6 sin6;
-       static char buf[PEX_BUF_SIZE];
-       struct pex_hdr *hdr = (struct pex_hdr *)buf;
+       static struct sockaddr_in6 sin6;
+       static char buf[PEX_RX_BUF_SIZE];
        ssize_t len;
 
        while (1) {
+               static struct iovec iov[2] = {
+                       { .iov_base = &sin6 },
+                       { .iov_base = buf },
+               };
+               static struct msghdr msg = {
+                       .msg_iov = iov,
+                       .msg_iovlen = ARRAY_SIZE(iov),
+               };
                socklen_t slen = sizeof(sin6);
 
                len = recvfrom(fd->fd, buf, sizeof(buf), 0, (struct sockaddr *)&sin6, &slen);
@@ -128,38 +171,157 @@ pex_fd_cb(struct uloop_fd *fd, unsigned int events)
                if (!len)
                        continue;
 
-               if (len < sizeof(*hdr) + sizeof(struct pex_ext_hdr))
+               if (IN6_IS_ADDR_V4MAPPED(&sin6.sin6_addr)) {
+                       struct sockaddr_in *sin = (struct sockaddr_in *)&sin6;
+                       struct in_addr in = *(struct in_addr *)&sin6.sin6_addr.s6_addr[12];
+                       int port = sin6.sin6_port;
+
+                       memset(&sin6, 0, sizeof(sin6));
+                       sin->sin_port = port;
+                       sin->sin_family = AF_INET;
+                       sin->sin_addr = in;
+                       slen = sizeof(*sin);
+               }
+
+retry:
+               if (pex_unix_tx_fd >= 0) {
+                       iov[0].iov_len = slen;
+                       iov[1].iov_len = len;
+                       if (sendmsg(pex_unix_tx_fd, &msg, 0) < 0) {
+                               switch (errno) {
+                               case EINTR:
+                                       goto retry;
+                               case EMSGSIZE:
+                               case ENOBUFS:
+                               case EAGAIN:
+                                       continue;
+                               default:
+                                       perror("sendmsg");
+                                       close(pex_unix_tx_fd);
+                                       pex_unix_tx_fd = -1;
+                                       break;
+                               }
+                       }
+               }
+
+               pex_recv_cb(buf, len, &sin6);
+       }
+}
+
+static void
+pex_unix_cb(struct uloop_fd *fd, unsigned int events)
+{
+       static char buf[PEX_RX_BUF_SIZE];
+       static struct iovec iov = {
+               .iov_base = buf,
+               .iov_len = sizeof(buf),
+       };
+       ssize_t len;
+
+       while (1) {
+               const struct sockaddr *sa = (struct sockaddr *)buf;
+               uint8_t fd_buf[CMSG_SPACE(sizeof(int))] = { 0 };
+               struct msghdr msg = {
+                       .msg_iov = &iov,
+                       .msg_iovlen = 1,
+                       .msg_control = fd_buf,
+                       .msg_controllen = CMSG_LEN(sizeof(int)),
+               };
+               struct cmsghdr *cmsg;
+               socklen_t slen;
+               int *pfd;
+
+               cmsg = CMSG_FIRSTHDR(&msg);
+               cmsg->cmsg_type = SCM_RIGHTS;
+               cmsg->cmsg_level = SOL_SOCKET;
+               cmsg->cmsg_len = CMSG_LEN(sizeof(int));
+
+               pfd = (int *)CMSG_DATA(cmsg);
+               *pfd = -1;
+
+               len = recvmsg(fd->fd, &msg, 0);
+               if (len < 0) {
+                       if (errno == EINTR)
+                               continue;
+
+                       if (errno == EAGAIN)
+                               break;
+
+                       pex_close();
+                       return;
+               }
+
+               if (*pfd >= 0) {
+                       if (pex_unix_tx_fd >= 0)
+                               close(pex_unix_tx_fd);
+
+                       pex_unix_tx_fd = *pfd;
+               }
+
+               if (!len)
                        continue;
 
-               hdr->len = ntohs(hdr->len);
-               if (len - sizeof(hdr) - sizeof(struct pex_ext_hdr) < hdr->len)
+               if (len < sizeof(*sa))
                        continue;
 
-               pex_recv_cb(hdr, &sin6);
+               if (sa->sa_family == AF_LOCAL) {
+                       slen = sizeof(struct sockaddr);
+                       len -= slen;
+                       if (len < sizeof(struct pex_msg_local_control))
+                               continue;
+
+                       if (pex_control_cb)
+                               pex_control_cb((struct pex_msg_local_control *)&buf[slen], len);
+
+                       continue;
+               }
+
+               if (sa->sa_family == AF_INET)
+                       slen = sizeof(struct sockaddr_in);
+               else if (sa->sa_family == AF_INET6)
+                       slen = sizeof(struct sockaddr_in6);
+               else
+                       continue;
+
+               sa = get_mapped_sockaddr(sa);
+               sendto(pex_fd.fd, buf + slen, len - slen, 0, sa, sizeof(struct sockaddr_in6));
        }
 }
 
-int __pex_msg_send(int fd, const void *addr)
+
+int __pex_msg_send(int fd, const void *addr, void *ip_hdr, size_t ip_hdrlen)
 {
        struct pex_hdr *hdr = (struct pex_hdr *)pex_tx_buf;
        const struct sockaddr *sa = addr;
        size_t tx_len = sizeof(*hdr) + hdr->len;
        uint16_t orig_len = hdr->len;
-       size_t addr_len;
        int ret;
 
        if (fd < 0) {
                hdr->len -= sizeof(struct pex_ext_hdr);
-               fd = pex_fd.fd;
+               if (ip_hdrlen)
+                       fd = pex_raw_socket(sa->sa_family);
+               else {
+                       fd = pex_fd.fd;
+                       sa = addr = get_mapped_sockaddr(addr);
+               }
+
+               if (fd < 0)
+                       return -1;
        }
 
        hdr->len = htons(hdr->len);
-       if (addr) {
+       if (ip_hdr) {
+               ret = sendto_rawudp(fd, addr, ip_hdr, ip_hdrlen, pex_tx_buf, tx_len);
+       } else if (addr) {
+               socklen_t addr_len;
+
                if (sa->sa_family == AF_INET6)
                        addr_len = sizeof(struct sockaddr_in6);
                else
                        addr_len = sizeof(struct sockaddr_in);
-               ret = sendto(fd, pex_tx_buf, tx_len, 0, sa, addr_len);
+
+               ret = sendto(fd, pex_tx_buf, tx_len, 0, addr, addr_len);
        } else {
                ret = send(fd, pex_tx_buf, tx_len, 0);
        }
@@ -203,7 +365,7 @@ void pex_msg_update_response_init(struct pex_msg_update_send_ctx *ctx,
 
        res = pex_msg_append(sizeof(*res));
        res->req_id = req->req_id;
-       res->data_len = len;
+       res->data_len = cpu_to_be32(len);
 
        if (!fread(e_key_priv, sizeof(e_key_priv), 1, pex_urandom))
                return;
@@ -238,7 +400,7 @@ bool pex_msg_update_response_continue(struct pex_msg_update_send_ctx *ctx)
 
        res_ext = pex_msg_append(sizeof(*res_ext));
        res_ext->req_id = ctx->req_id;
-       res_ext->offset = ctx->cur - ctx->data;
+       res_ext->offset = cpu_to_be32(ctx->cur - ctx->data);
        pex_msg_update_response_fill(ctx);
 
        return true;
@@ -262,8 +424,10 @@ pex_msg_update_request_init(const uint8_t *pubkey, const uint8_t *priv_key,
        memcpy(&ctx->addr, addr, sizeof(ctx->addr));
        memcpy(ctx->auth_key, auth_key, sizeof(ctx->auth_key));
        memcpy(ctx->priv_key, priv_key, sizeof(ctx->priv_key));
-       if (!fread(&ctx->req_id, sizeof(ctx->req_id), 1, pex_urandom))
+       if (!fread(&ctx->req_id, sizeof(ctx->req_id), 1, pex_urandom)) {
+               free(ctx);
                return NULL;
+       }
        list_add_tail(&ctx->list, &requests);
        if (!gc_timer.pending)
                uloop_timeout_set(&gc_timer, 1000);
@@ -318,13 +482,13 @@ void *pex_msg_update_response_recv(const void *data, int len, enum pex_opcode op
 
                ctx = pex_msg_update_recv_ctx_get(res->req_id);
                if (!ctx || ctx->data_len || !res->data_len ||
-                   res->data_len > UNETD_NET_DATA_SIZE_MAX)
+                   be32_to_cpu(res->data_len) > UNETD_NET_DATA_SIZE_MAX)
                        return NULL;
 
                data += sizeof(*res);
                len -= sizeof(*res);
 
-               ctx->data_len = res->data_len;
+               ctx->data_len = be32_to_cpu(res->data_len);
                memcpy(ctx->e_key, res->e_key, sizeof(ctx->e_key));
                ctx->data = malloc(ctx->data_len);
        } else if (op == PEX_MSG_UPDATE_RESPONSE_DATA) {
@@ -334,7 +498,7 @@ void *pex_msg_update_response_recv(const void *data, int len, enum pex_opcode op
                        return NULL;
 
                ctx = pex_msg_update_recv_ctx_get(res->req_id);
-               if (!ctx || ctx->data_ofs != res->offset)
+               if (!ctx || ctx->data_ofs != be32_to_cpu(res->offset))
                        return NULL;
 
                data += sizeof(*res);
@@ -380,6 +544,28 @@ error:
        return NULL;
 }
 
+struct pex_hdr *pex_rx_accept(void *data, size_t len, bool ext)
+{
+       struct pex_hdr *hdr = data;
+       uint16_t hdr_len;
+       size_t min_size;
+
+       min_size = sizeof(*hdr);
+       if (ext)
+               min_size += sizeof(struct pex_ext_hdr);
+
+       if (len < min_size)
+               return NULL;
+
+       hdr_len = ntohs(hdr->len);
+       if (len < min_size + hdr_len)
+               return NULL;
+
+       hdr->len = hdr_len;
+
+       return hdr;
+}
+
 static void
 pex_gc_cb(struct uloop_timeout *t)
 {
@@ -404,9 +590,28 @@ int pex_open(void *addr, size_t addr_len, pex_recv_cb_t cb, bool server)
 
        pex_recv_cb = cb;
 
+       if (server) {
+               pex_raw_v4_fd = fd = socket(PF_INET, SOCK_RAW, IPPROTO_UDP);
+               if (fd < 0)
+                       return -1;
+
+               setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &yes, sizeof(yes));
+               setsockopt(fd, IPPROTO_IP, IP_HDRINCL, &yes, sizeof(yes));
+
+#ifdef linux
+               pex_raw_v6_fd = fd = socket(PF_INET6, SOCK_RAW, IPPROTO_UDP);
+               if (fd < 0)
+                       goto close_raw;
+
+               setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &yes, sizeof(yes));
+               setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &no, sizeof(no));
+               setsockopt(fd, IPPROTO_IPV6, IPV6_HDRINCL, &yes, sizeof(yes));
+#endif
+       }
+
        pex_urandom = fopen("/dev/urandom", "r");
        if (!pex_urandom)
-               return -1;
+               goto close_raw;
 
        fd = socket(sa->sa_family == AF_INET ? PF_INET : PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
        if (fd < 0)
@@ -443,17 +648,60 @@ close_socket:
        close(fd);
 close_urandom:
        fclose(pex_urandom);
+close_raw:
+       if (pex_raw_v4_fd >= 0)
+               close(pex_raw_v4_fd);
+       if (pex_raw_v6_fd >= 0)
+               close(pex_raw_v6_fd);
+       pex_raw_v4_fd = -1;
+       pex_raw_v6_fd = -1;
        return -1;
 }
 
+int pex_unix_open(const char *path, pex_recv_control_cb_t cb)
+{
+       mode_t prev_mask;
+       int fd;
+
+       pex_control_cb = cb;
+       unlink(path);
+
+       prev_mask = umask(0177);
+       fd = usock(USOCK_UDP | USOCK_UNIX | USOCK_SERVER | USOCK_NONBLOCK, path, NULL);
+       umask(prev_mask);
+       if (fd < 0)
+               return -1;
+
+       pex_unix_fd.cb = pex_unix_cb;
+       pex_unix_fd.fd = fd;
+       uloop_fd_add(&pex_unix_fd, ULOOP_READ);
+
+       return 0;
+}
+
 void pex_close(void)
 {
-       if (!pex_fd.cb)
-               return;
+       if (pex_raw_v4_fd >= 0)
+               close(pex_raw_v4_fd);
+       if (pex_raw_v6_fd >= 0)
+               close(pex_raw_v6_fd);
+       pex_raw_v4_fd = -1;
+       pex_raw_v6_fd = -1;
+
+       if (pex_urandom)
+               fclose(pex_urandom);
+
+       if (pex_fd.cb) {
+               uloop_fd_delete(&pex_fd);
+               close(pex_fd.fd);
+       }
+
+       if (pex_unix_fd.cb) {
+               uloop_fd_delete(&pex_unix_fd);
+               close(pex_unix_fd.fd);
+       }
 
-       fclose(pex_urandom);
-       uloop_fd_delete(&pex_fd);
-       close(pex_fd.fd);
        pex_fd.cb = NULL;
+       pex_unix_fd.cb = NULL;
        pex_urandom = NULL;
 }