pex: move raw ip send code to sendto_rawudp() in utils.c

This allows it to be reused for other purposes later

Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/pex-msg.c b/pex-msg.c
index f6cbd71179e6e0a8b0c8155010c0e0e69e7927ff..f4da871ebc7a36abe9f7d12f6228575a381ff7e7 100644 (file)
--- a/pex-msg.c
+++ b/pex-msg.c
@@ -11,10 +11,6 @@
 #include <libubox/list.h>
 #include <libubox/uloop.h>
 #include <libubox/usock.h>
-#include <netinet/in.h>
-#include <netinet/ip.h>
-#include <netinet/ip6.h>
-#include <netinet/udp.h>
 #include "pex-msg.h"
 #include "chacha20.h"
 #include "auth-data.h"
@@ -282,115 +278,6 @@ pex_unix_cb(struct uloop_fd *fd, unsigned int events)
        }
 }
 
-static inline uint32_t
-csum_tcpudp_nofold(uint32_t saddr, uint32_t daddr, uint32_t len, uint8_t proto)
-{
-       uint64_t sum = 0;
-
-       sum += saddr;
-       sum += daddr;
-#if __BYTE_ORDER == __LITTLE_ENDIAN
-       sum += (proto + len) << 8;
-#else
-       sum += proto + len;
-#endif
-
-       sum = (sum & 0xffffffff) + (sum >> 32);
-       sum = (sum & 0xffffffff) + (sum >> 32);
-
-       return (uint32_t)sum;
-}
-
-static inline uint32_t csum_add(uint32_t sum, uint32_t addend)
-{
-       sum += addend;
-       return sum + (sum < addend);
-}
-
-static inline uint16_t csum_fold(uint32_t sum)
-{
-       sum = (sum & 0xffff) + (sum >> 16);
-       sum = (sum & 0xffff) + (sum >> 16);
-
-       return (uint16_t)~sum;
-}
-
-static uint32_t csum_partial(const void *buf, int len)
-{
-       const uint16_t *data = buf;
-       uint32_t sum = 0;
-
-       while (len > 1) {
-               sum += *data++;
-               len -= 2;
-       }
-
-       if (len == 1)
-#if __BYTE_ORDER == __LITTLE_ENDIAN
-               sum += *(uint8_t *)data;
-#else
-               sum += *(uint8_t *)data << 8;
-#endif
-
-       sum = (sum & 0xffff) + (sum >> 16);
-       sum = (sum & 0xffff) + (sum >> 16);
-
-       return sum;
-}
-
-static void pex_fixup_udpv4(void *hdr, size_t hdrlen, const void *data, size_t len)
-{
-       struct ip *ip = hdr;
-       struct udphdr *udp = hdr + ip->ip_hl * 4;
-       uint16_t udp_len = sizeof(*udp) + len;
-       uint32_t sum;
-
-       if ((void *)&udp[1] > hdr + hdrlen)
-               return;
-
-       udp->uh_sum = 0;
-       udp->uh_ulen = htons(udp_len);
-       sum = csum_tcpudp_nofold(*(uint32_t *)&ip->ip_src, *(uint32_t *)&ip->ip_dst,
-                                ip->ip_p, udp_len);
-       sum = csum_add(sum, csum_partial(udp, sizeof(*udp)));
-       sum = csum_add(sum, csum_partial(data, len));
-       udp->uh_sum = csum_fold(sum);
-
-       ip->ip_len = htons(hdrlen + len);
-       ip->ip_sum = 0;
-       ip->ip_sum = csum_fold(csum_partial(ip, sizeof(*ip)));
-
-#ifdef __APPLE__
-       ip->ip_len = hdrlen + len;
-#endif
-}
-
-static void pex_fixup_udpv6(void *hdr, size_t hdrlen, const void *data, size_t len)
-{
-       struct ip6_hdr *ip = hdr;
-       struct udphdr *udp = hdr + sizeof(*ip);
-       uint16_t udp_len = htons(sizeof(*udp) + len);
-
-       if ((void *)&udp[1] > hdr + hdrlen)
-               return;
-
-       ip->ip6_plen = htons(sizeof(*udp) + len);
-       udp->uh_sum = 0;
-       udp->uh_ulen = udp_len;
-       udp->uh_sum = csum_fold(csum_partial(hdr, sizeof(*ip) + sizeof(*udp)));
-
-#ifdef __APPLE__
-       ip->ip6_plen = sizeof(*udp) + len;
-#endif
-}
-
-static void pex_fixup_header(void *hdr, size_t hdrlen, const void *data, size_t len)
-{
-       if (hdrlen >= sizeof(struct ip6_hdr) + sizeof(struct udphdr))
-               pex_fixup_udpv6(hdr, hdrlen, data, len);
-       else if (hdrlen >= sizeof(struct ip) + sizeof(struct udphdr))
-               pex_fixup_udpv4(hdr, hdrlen, data, len);
-}
 
 int __pex_msg_send(int fd, const void *addr, void *ip_hdr, size_t ip_hdrlen)
 {
@@ -414,30 +301,17 @@ int __pex_msg_send(int fd, const void *addr, void *ip_hdr, size_t ip_hdrlen)
        }
 
        hdr->len = htons(hdr->len);
-       if (addr) {
-               struct iovec iov[2] = {
-                       { .iov_base = (void *)ip_hdr, .iov_len = ip_hdrlen },
-                       { .iov_base = pex_tx_buf, .iov_len = tx_len }
-               };
-               struct msghdr msg = {
-                       .msg_name = (void *)addr,
-                       .msg_iov = iov,
-                       .msg_iovlen = ARRAY_SIZE(iov),
-               };
+       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)
-                       msg.msg_namelen = sizeof(struct sockaddr_in6);
+                       addr_len = sizeof(struct sockaddr_in6);
                else
-                       msg.msg_namelen = sizeof(struct sockaddr_in);
-
-               if (ip_hdrlen) {
-                       pex_fixup_header(ip_hdr, ip_hdrlen, pex_tx_buf, tx_len);
-               } else {
-                       msg.msg_iov++;
-                       msg.msg_iovlen--;
-               }
+                       addr_len = sizeof(struct sockaddr_in);
 
-               ret = sendmsg(fd, &msg, 0);
+               ret = sendto(fd, pex_tx_buf, tx_len, 0, addr, addr_len);
        } else {
                ret = send(fd, pex_tx_buf, tx_len, 0);
        }

diff --git a/utils.c b/utils.c
index abaa73d2367edecaab68f36003e6407efadfdcb5..0c7067173f733681493e4f2c95aeb70c829b8e0d 100644 (file)
--- a/utils.c
+++ b/utils.c
@@ -8,6 +8,10 @@
 #include <arpa/inet.h>
 #include <netdb.h>
 #include <stdio.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <netinet/ip6.h>
+#include <netinet/udp.h>
 
 #include <libubox/utils.h>
 
@@ -191,3 +195,137 @@ uint64_t unet_gettime(void)
 
        return ts.tv_sec;
 }
+
+static inline uint32_t
+csum_tcpudp_nofold(uint32_t saddr, uint32_t daddr, uint32_t len, uint8_t proto)
+{
+       uint64_t sum = 0;
+
+       sum += saddr;
+       sum += daddr;
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+       sum += (proto + len) << 8;
+#else
+       sum += proto + len;
+#endif
+
+       sum = (sum & 0xffffffff) + (sum >> 32);
+       sum = (sum & 0xffffffff) + (sum >> 32);
+
+       return (uint32_t)sum;
+}
+
+static inline uint32_t csum_add(uint32_t sum, uint32_t addend)
+{
+       sum += addend;
+       return sum + (sum < addend);
+}
+
+static inline uint16_t csum_fold(uint32_t sum)
+{
+       sum = (sum & 0xffff) + (sum >> 16);
+       sum = (sum & 0xffff) + (sum >> 16);
+
+       return (uint16_t)~sum;
+}
+
+static uint32_t csum_partial(const void *buf, int len)
+{
+       const uint16_t *data = buf;
+       uint32_t sum = 0;
+
+       while (len > 1) {
+               sum += *data++;
+               len -= 2;
+       }
+
+       if (len == 1)
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+               sum += *(uint8_t *)data;
+#else
+               sum += *(uint8_t *)data << 8;
+#endif
+
+       sum = (sum & 0xffff) + (sum >> 16);
+       sum = (sum & 0xffff) + (sum >> 16);
+
+       return sum;
+}
+
+static void fixup_udpv4(void *hdr, size_t hdrlen, const void *data, size_t len)
+{
+       struct ip *ip = hdr;
+       struct udphdr *udp = hdr + ip->ip_hl * 4;
+       uint16_t udp_len = sizeof(*udp) + len;
+       uint32_t sum;
+
+       if ((void *)&udp[1] > hdr + hdrlen)
+               return;
+
+       udp->uh_sum = 0;
+       udp->uh_ulen = htons(udp_len);
+       sum = csum_tcpudp_nofold(*(uint32_t *)&ip->ip_src, *(uint32_t *)&ip->ip_dst,
+                                ip->ip_p, udp_len);
+       sum = csum_add(sum, csum_partial(udp, sizeof(*udp)));
+       sum = csum_add(sum, csum_partial(data, len));
+       udp->uh_sum = csum_fold(sum);
+
+       ip->ip_len = htons(hdrlen + len);
+       ip->ip_sum = 0;
+       ip->ip_sum = csum_fold(csum_partial(ip, sizeof(*ip)));
+
+#ifdef __APPLE__
+       ip->ip_len = hdrlen + len;
+#endif
+}
+
+static void fixup_udpv6(void *hdr, size_t hdrlen, const void *data, size_t len)
+{
+       struct ip6_hdr *ip = hdr;
+       struct udphdr *udp = hdr + sizeof(*ip);
+       uint16_t udp_len = htons(sizeof(*udp) + len);
+
+       if ((void *)&udp[1] > hdr + hdrlen)
+               return;
+
+       ip->ip6_plen = htons(sizeof(*udp) + len);
+       udp->uh_sum = 0;
+       udp->uh_ulen = udp_len;
+       udp->uh_sum = csum_fold(csum_partial(hdr, sizeof(*ip) + sizeof(*udp)));
+
+#ifdef __APPLE__
+       ip->ip6_plen = sizeof(*udp) + len;
+#endif
+}
+
+static void fixup_ip_udp_header(void *hdr, size_t hdrlen, const void *data, size_t len)
+{
+       if (hdrlen >= sizeof(struct ip6_hdr) + sizeof(struct udphdr))
+               fixup_udpv6(hdr, hdrlen, data, len);
+       else if (hdrlen >= sizeof(struct ip) + sizeof(struct udphdr))
+               fixup_udpv4(hdr, hdrlen, data, len);
+}
+
+int sendto_rawudp(int fd, const void *addr, void *ip_hdr, size_t ip_hdrlen,
+                 const void *data, size_t len)
+{
+       const struct sockaddr *sa = addr;
+       struct iovec iov[2] = {
+               { .iov_base = ip_hdr, .iov_len = ip_hdrlen },
+               { .iov_base = (void *)data, .iov_len = len }
+       };
+       struct msghdr msg = {
+               .msg_name = (void *)addr,
+               .msg_iov = iov,
+               .msg_iovlen = ARRAY_SIZE(iov),
+       };
+
+       if (sa->sa_family == AF_INET6)
+               msg.msg_namelen = sizeof(struct sockaddr_in6);
+       else
+               msg.msg_namelen = sizeof(struct sockaddr_in);
+
+       fixup_ip_udp_header(ip_hdr, ip_hdrlen, data, len);
+
+       return sendmsg(fd, &msg, 0);
+}

diff --git a/utils.h b/utils.h
index d79d96c1e9a7c1dcfa8f20845c4390ea5dc00652..164070af8df9851962b2215da54722424a257d69 100644 (file)
--- a/utils.h
+++ b/utils.h
@@ -125,4 +125,7 @@ int rtnl_call(struct nl_msg *msg);
 
 uint64_t unet_gettime(void);
 
+int sendto_rawudp(int fd, const void *addr, void *ip_hdr, size_t ip_hdrlen,
+                 const void *data, size_t len);
+
 #endif