X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fsocket-util.c;h=9fea7bdab55455951929e304185578f46c6f4ea6;hb=780325b5b8d4c0552b4b7719e0a38200d99f6b08;hp=939cd90ff8a8eef55cb809a775c424dadad9d4ac;hpb=a0505c49dd98b393f4c47a423f325008443eb1ee;p=sliver-openvswitch.git diff --git a/lib/socket-util.c b/lib/socket-util.c index 939cd90ff..9fea7bdab 100644 --- a/lib/socket-util.c +++ b/lib/socket-util.c @@ -17,7 +17,6 @@ #include #include "socket-util.h" #include -#include #include #include #include @@ -30,14 +29,16 @@ #include #include #include +#include #include #include #include "dynamic-string.h" #include "fatal-signal.h" #include "packets.h" +#include "poll-loop.h" #include "util.h" #include "vlog.h" -#if AF_PACKET && __linux__ +#if AF_PACKET && LINUX_DATAPATH #include #endif #ifdef HAVE_NETLINK @@ -49,11 +50,9 @@ VLOG_DEFINE_THIS_MODULE(socket_util); /* #ifdefs make it a pain to maintain code: you have to try to build both ways. * Thus, this file compiles all of the code regardless of the target, by - * writing "if (LINUX)" instead of "#ifdef __linux__". */ -#ifdef __linux__ -#define LINUX 1 -#else -#define LINUX 0 + * writing "if (LINUX_DATAPATH)" instead of "#ifdef __linux__". */ +#ifndef LINUX_DATAPATH +#define LINUX_DATAPATH 0 #endif #ifndef O_DIRECTORY @@ -90,15 +89,17 @@ xset_nonblocking(int fd) } } -static int +int set_dscp(int fd, uint8_t dscp) { + int val; + if (dscp > 63) { return EINVAL; } - dscp = dscp << 2; - if (setsockopt(fd, IPPROTO_IP, IP_TOS, &dscp, sizeof dscp)) { + val = dscp << 2; + if (setsockopt(fd, IPPROTO_IP, IP_TOS, &val, sizeof val)) { return errno; } @@ -179,7 +180,7 @@ lookup_ipv6(const char *host_name, struct in6_addr *addr) * Most Open vSwitch code should not use this because it causes deadlocks: * gethostbyname() sends out a DNS request but that starts a new flow for which * OVS must set up a flow, but it can't because it's waiting for a DNS reply. - * The synchronous lookup also delays other activty. (Of course we can solve + * The synchronous lookup also delays other activity. (Of course we can solve * this but it doesn't seem worthwhile quite yet.) */ int lookup_hostname(const char *host_name, struct in_addr *addr) @@ -203,22 +204,10 @@ lookup_hostname(const char *host_name, struct in_addr *addr) : EINVAL); } -/* Returns the error condition associated with socket 'fd' and resets the - * socket's error status. */ -int -get_socket_error(int fd) -{ - int error; - - if (getsockopt_int(fd, SOL_SOCKET, SO_ERROR, "SO_ERROR", &error)) { - error = errno; - } - return error; -} - int check_connection_completion(int fd) { + static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10); struct pollfd pfd; int retval; @@ -228,9 +217,17 @@ check_connection_completion(int fd) retval = poll(&pfd, 1, 0); } while (retval < 0 && errno == EINTR); if (retval == 1) { - return get_socket_error(fd); + if (pfd.revents & POLLERR) { + ssize_t n = send(fd, "", 1, MSG_DONTWAIT); + if (n < 0) { + return errno; + } else { + VLOG_ERR_RL(&rl, "poll return POLLERR but send succeeded"); + return EPROTO; + } + } + return 0; } else if (retval < 0) { - static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10); VLOG_ERR_RL(&rl, "poll: %s", strerror(errno)); return errno; } else { @@ -262,7 +259,7 @@ drain_rcvbuf(int fd) * * On other Unix-like OSes, MSG_TRUNC has no effect in the flags * argument. */ - char buffer[LINUX ? 1 : 2048]; + char buffer[LINUX_DATAPATH ? 1 : 2048]; ssize_t n_bytes = recv(fd, buffer, sizeof buffer, MSG_TRUNC | MSG_DONTWAIT); if (n_bytes <= 0 || n_bytes >= rcvbuf) { @@ -331,7 +328,7 @@ make_sockaddr_un(const char *name, struct sockaddr_un *un, socklen_t *un_len, if (strlen(name) > MAX_UN_LEN) { static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1); - if (LINUX) { + if (LINUX_DATAPATH) { /* 'name' is too long to fit in a sockaddr_un, but we have a * workaround for that on Linux: shorten it by opening a file * descriptor for the directory part of the name and indirecting @@ -412,13 +409,8 @@ make_unix_socket(int style, bool nonblock, * it will only happen if style is SOCK_STREAM or SOCK_SEQPACKET, and only * if a backlog of un-accepted connections has built up in the kernel.) */ if (nonblock) { - int flags = fcntl(fd, F_GETFL, 0); - if (flags == -1) { - error = errno; - goto error; - } - if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) { - error = errno; + error = set_nonblocking(fd); + if (error) { goto error; } } @@ -610,6 +602,7 @@ exit: } } else if (fd >= 0) { close(fd); + fd = -1; } *fdp = fd; return error; @@ -889,6 +882,22 @@ xpipe(int fds[2]) } } +void +xpipe_nonblocking(int fds[2]) +{ + xpipe(fds); + xset_nonblocking(fds[0]); + xset_nonblocking(fds[1]); +} + +void +xsocketpair(int domain, int type, int protocol, int fds[2]) +{ + if (socketpair(domain, type, protocol, fds)) { + VLOG_FATAL("failed to create socketpair (%s)", strerror(errno)); + } +} + static int getsockopt_int(int fd, int level, int option, const char *optname, int *valuep) { @@ -926,7 +935,7 @@ describe_sockaddr(struct ds *string, int fd, memcpy(&sin, &ss, sizeof sin); ds_put_format(string, IP_FMT":%"PRIu16, - IP_ARGS(&sin.sin_addr.s_addr), ntohs(sin.sin_port)); + IP_ARGS(sin.sin_addr.s_addr), ntohs(sin.sin_port)); } else if (ss.ss_family == AF_UNIX) { struct sockaddr_un sun; const char *null; @@ -968,7 +977,7 @@ describe_sockaddr(struct ds *string, int fd, } } #endif -#if AF_PACKET && __linux__ +#if AF_PACKET && LINUX_DATAPATH else if (ss.ss_family == AF_PACKET) { struct sockaddr_ll sll; @@ -998,7 +1007,7 @@ describe_sockaddr(struct ds *string, int fd, } -#ifdef __linux__ +#ifdef LINUX_DATAPATH static void put_fd_filename(struct ds *string, int fd) { @@ -1042,9 +1051,255 @@ describe_fd(int fd) : S_ISFIFO(s.st_mode) ? "FIFO" : S_ISLNK(s.st_mode) ? "symbolic link" : "unknown")); -#ifdef __linux__ +#ifdef LINUX_DATAPATH put_fd_filename(&string, fd); #endif } return ds_steal_cstr(&string); } + +/* Returns the total of the 'iov_len' members of the 'n_iovs' in 'iovs'. + * The caller must ensure that the total does not exceed SIZE_MAX. */ +size_t +iovec_len(const struct iovec iovs[], size_t n_iovs) +{ + size_t len = 0; + size_t i; + + for (i = 0; i < n_iovs; i++) { + len += iovs[i].iov_len; + } + return len; +} + +/* Returns true if all of the 'n_iovs' iovecs in 'iovs' have length zero. */ +bool +iovec_is_empty(const struct iovec iovs[], size_t n_iovs) +{ + size_t i; + + for (i = 0; i < n_iovs; i++) { + if (iovs[i].iov_len) { + return false; + } + } + return true; +} + +/* Sends the 'n_iovs' iovecs of data in 'iovs' and the 'n_fds' file descriptors + * in 'fds' on Unix domain socket 'sock'. Returns the number of bytes + * successfully sent or -1 if an error occurred. On error, sets errno + * appropriately. */ +int +send_iovec_and_fds(int sock, + const struct iovec *iovs, size_t n_iovs, + const int fds[], size_t n_fds) +{ + ovs_assert(sock >= 0); + if (n_fds > 0) { + union { + struct cmsghdr cm; + char control[CMSG_SPACE(SOUTIL_MAX_FDS * sizeof *fds)]; + } cmsg; + struct msghdr msg; + + ovs_assert(!iovec_is_empty(iovs, n_iovs)); + ovs_assert(n_fds <= SOUTIL_MAX_FDS); + + memset(&cmsg, 0, sizeof cmsg); + cmsg.cm.cmsg_len = CMSG_LEN(n_fds * sizeof *fds); + cmsg.cm.cmsg_level = SOL_SOCKET; + cmsg.cm.cmsg_type = SCM_RIGHTS; + memcpy(CMSG_DATA(&cmsg.cm), fds, n_fds * sizeof *fds); + + msg.msg_name = NULL; + msg.msg_namelen = 0; + msg.msg_iov = CONST_CAST(struct iovec *, iovs); + msg.msg_iovlen = n_iovs; + msg.msg_control = &cmsg.cm; + msg.msg_controllen = CMSG_SPACE(n_fds * sizeof *fds); + msg.msg_flags = 0; + + return sendmsg(sock, &msg, 0); + } else { + return writev(sock, iovs, n_iovs); + } +} + +/* Sends the 'n_iovs' iovecs of data in 'iovs' and the 'n_fds' file descriptors + * in 'fds' on Unix domain socket 'sock'. If 'skip_bytes' is nonzero, then the + * first 'skip_bytes' of data in the iovecs are not sent, and none of the file + * descriptors are sent. The function continues to retry sending until an + * error (other than EINTR) occurs or all the data and fds are sent. + * + * Returns 0 if all the data and fds were successfully sent, otherwise a + * positive errno value. Regardless of success, stores the number of bytes + * sent (always at least 'skip_bytes') in '*bytes_sent'. (If at least one byte + * is sent, then all the fds have been sent.) + * + * 'skip_bytes' must be less than or equal to iovec_len(iovs, n_iovs). */ +int +send_iovec_and_fds_fully(int sock, + const struct iovec iovs[], size_t n_iovs, + const int fds[], size_t n_fds, + size_t skip_bytes, size_t *bytes_sent) +{ + *bytes_sent = 0; + while (n_iovs > 0) { + int retval; + + if (skip_bytes) { + retval = skip_bytes; + skip_bytes = 0; + } else if (!*bytes_sent) { + retval = send_iovec_and_fds(sock, iovs, n_iovs, fds, n_fds); + } else { + retval = writev(sock, iovs, n_iovs); + } + + if (retval > 0) { + *bytes_sent += retval; + while (retval > 0) { + const uint8_t *base = iovs->iov_base; + size_t len = iovs->iov_len; + + if (retval < len) { + size_t sent; + int error; + + error = write_fully(sock, base + retval, len - retval, + &sent); + *bytes_sent += sent; + retval += sent; + if (error) { + return error; + } + } + retval -= len; + iovs++; + n_iovs--; + } + } else if (retval == 0) { + if (iovec_is_empty(iovs, n_iovs)) { + break; + } + VLOG_WARN("send returned 0"); + return EPROTO; + } else if (errno != EINTR) { + return errno; + } + } + + return 0; +} + +/* Sends the 'n_iovs' iovecs of data in 'iovs' and the 'n_fds' file descriptors + * in 'fds' on Unix domain socket 'sock'. The function continues to retry + * sending until an error (other than EAGAIN or EINTR) occurs or all the data + * and fds are sent. Upon EAGAIN, the function blocks until the socket is + * ready for more data. + * + * Returns 0 if all the data and fds were successfully sent, otherwise a + * positive errno value. */ +int +send_iovec_and_fds_fully_block(int sock, + const struct iovec iovs[], size_t n_iovs, + const int fds[], size_t n_fds) +{ + size_t sent = 0; + + for (;;) { + int error; + + error = send_iovec_and_fds_fully(sock, iovs, n_iovs, + fds, n_fds, sent, &sent); + if (error != EAGAIN) { + return error; + } + poll_fd_wait(sock, POLLOUT); + poll_block(); + } +} + +/* Attempts to receive from Unix domain socket 'sock' up to 'size' bytes of + * data into 'data' and up to SOUTIL_MAX_FDS file descriptors into 'fds'. + * + * - Upon success, returns the number of bytes of data copied into 'data' + * and stores the number of received file descriptors into '*n_fdsp'. + * + * - On failure, returns a negative errno value and stores 0 in + * '*n_fdsp'. + * + * - On EOF, returns 0 and stores 0 in '*n_fdsp'. */ +int +recv_data_and_fds(int sock, + void *data, size_t size, + int fds[SOUTIL_MAX_FDS], size_t *n_fdsp) +{ + union { + struct cmsghdr cm; + char control[CMSG_SPACE(SOUTIL_MAX_FDS * sizeof *fds)]; + } cmsg; + struct msghdr msg; + int retval; + struct cmsghdr *p; + size_t i; + + *n_fdsp = 0; + + do { + struct iovec iov; + + iov.iov_base = data; + iov.iov_len = size; + + msg.msg_name = NULL; + msg.msg_namelen = 0; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + msg.msg_control = &cmsg.cm; + msg.msg_controllen = sizeof cmsg.control; + msg.msg_flags = 0; + + retval = recvmsg(sock, &msg, 0); + } while (retval < 0 && errno == EINTR); + if (retval <= 0) { + return retval < 0 ? -errno : 0; + } + + for (p = CMSG_FIRSTHDR(&msg); p; p = CMSG_NXTHDR(&msg, p)) { + if (p->cmsg_level != SOL_SOCKET || p->cmsg_type != SCM_RIGHTS) { + VLOG_ERR("unexpected control message %d:%d", + p->cmsg_level, p->cmsg_type); + goto error; + } else if (*n_fdsp) { + VLOG_ERR("multiple SCM_RIGHTS received"); + goto error; + } else { + size_t n_fds = (p->cmsg_len - CMSG_LEN(0)) / sizeof *fds; + const int *fds_data = (const int *) CMSG_DATA(p); + + ovs_assert(n_fds > 0); + if (n_fds > SOUTIL_MAX_FDS) { + VLOG_ERR("%zu fds received but only %d supported", + n_fds, SOUTIL_MAX_FDS); + for (i = 0; i < n_fds; i++) { + close(fds_data[i]); + } + goto error; + } + + *n_fdsp = n_fds; + memcpy(fds, fds_data, n_fds * sizeof *fds); + } + } + + return retval; + +error: + for (i = 0; i < *n_fdsp; i++) { + close(fds[i]); + } + *n_fdsp = 0; + return EPROTO; +}