From 3f464fc007ace5a829e8d43e72a88055f14b52e3 Mon Sep 17 00:00:00 2001 From: Pau Espin Pedrol Date: Thu, 10 Oct 2019 17:38:35 +0200 Subject: socket: Introduce API osmo_sock_init2_multiaddr() This API will be used by libosmo-netif's osmo_stream for SCTP sockets, which in turn will be used by libosmo-sccp to support multi-homed connections. Related: OS#3608 Change-Id: Ic8681d9e093216c99c6bca4be81c31ef83688ed1 --- src/Makefile.am | 4 +- src/socket.c | 286 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 288 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/Makefile.am b/src/Makefile.am index 5f5f0171..99432811 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -4,7 +4,7 @@ LIBVERSION=14:0:2 AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_builddir)/include -AM_CFLAGS = -Wall $(TALLOC_CFLAGS) $(PTHREAD_CFLAGS) +AM_CFLAGS = -Wall $(TALLOC_CFLAGS) $(PTHREAD_CFLAGS) $(LIBSCTP_CFLAGS) if ENABLE_PSEUDOTALLOC AM_CPPFLAGS += -I$(top_srcdir)/src/pseudotalloc @@ -12,7 +12,7 @@ endif lib_LTLIBRARIES = libosmocore.la -libosmocore_la_LIBADD = $(BACKTRACE_LIB) $(TALLOC_LIBS) $(LIBRARY_RT) $(PTHREAD_LIBS) +libosmocore_la_LIBADD = $(BACKTRACE_LIB) $(TALLOC_LIBS) $(LIBRARY_RT) $(PTHREAD_LIBS) $(LIBSCTP_LIBS) libosmocore_la_SOURCES = context.c timer.c timer_gettimeofday.c timer_clockgettime.c \ select.c signal.c msgb.c bits.c \ bitvec.c bitcomp.c counter.c fsm.c \ diff --git a/src/socket.c b/src/socket.c index ef3bb58d..542c76e5 100644 --- a/src/socket.c +++ b/src/socket.c @@ -53,6 +53,10 @@ #include #include +#ifdef HAVE_LIBSCTP +#include +#endif + static struct addrinfo *addrinfo_helper(uint16_t family, uint16_t type, uint8_t proto, const char *host, uint16_t port, bool passive) { @@ -96,6 +100,34 @@ static struct addrinfo *addrinfo_helper(uint16_t family, uint16_t type, uint8_t return result; } +/*! Retrieve an array of addrinfo with specified hints, one for each host in the hosts array. + * \param[out] addrinfo array of addrinfo pointers, will be filled by the function on success. + * Its size must be at least the one of hosts. + * \param[in] family Socket family like AF_INET, AF_INET6. + * \param[in] type Socket type like SOCK_DGRAM, SOCK_STREAM. + * \param[in] proto Protocol like IPPROTO_TCP, IPPROTO_UDP. + * \param[in] hosts array of char pointers (strings) containing the addresses to query. + * \param[in] host_cnt length of the hosts array (in items). + * \param[in] port port number in host byte order. + * \param[in] passive whether to include the AI_PASSIVE flag in getaddrinfo() hints. + * \returns 0 is returned on success together with a filled addrinfo array; negative on error + */ +static int addrinfo_helper_multi(struct addrinfo **addrinfo, uint16_t family, uint16_t type, uint8_t proto, + const char **hosts, size_t host_cnt, uint16_t port, bool passive) +{ + int i, j; + + for (i = 0; i < host_cnt; i++) { + addrinfo[i] = addrinfo_helper(family, type, proto, hosts[i], port, passive); + if (!addrinfo[i]) { + for (j = 0; j < i; j++) + freeaddrinfo(addrinfo[j]); + return -EINVAL; + } + } + return 0; +} + static int socket_helper(const struct addrinfo *rp, unsigned int flags) { int sfd, on = 1; @@ -118,6 +150,37 @@ static int socket_helper(const struct addrinfo *rp, unsigned int flags) return sfd; } +/* Fill buf with a string representation of the address set, in the form: + * buf_len == 0: "()" + * buf_len == 1: "hostA" + * buf_len >= 2: (hostA|hostB|...|...) + */ +static int multiaddr_snprintf(char* buf, size_t buf_len, const char **hosts, size_t host_cnt) +{ + int len = 0, offset = 0, rem = buf_len; + int ret, i; + char *after; + + if (buf_len < 3) + return -EINVAL; + + if (host_cnt != 1) { + ret = snprintf(buf, rem, "("); + if (ret < 0) + return ret; + OSMO_SNPRINTF_RET(ret, rem, offset, len); + } + for (i = 0; i < host_cnt; i++) { + if (host_cnt == 1) + after = ""; + else + after = (i == (host_cnt - 1)) ? ")" : "|"; + ret = snprintf(buf + offset, rem, "%s%s", hosts[i] ? : "0.0.0.0", after); + OSMO_SNPRINTF_RET(ret, rem, offset, len); + } + + return len; +} static int osmo_sock_init_tail(int fd, uint16_t type, unsigned int flags) { @@ -294,6 +357,229 @@ int osmo_sock_init2(uint16_t family, uint16_t type, uint8_t proto, return sfd; } +#ifdef HAVE_LIBSCTP + + +/* Build array of addresses taking first addrinfo result of the requested family + * for each host in hosts. addrs4 or addrs6 are filled based on family type. */ +static int addrinfo_to_sockaddr(uint16_t family, const struct addrinfo **result, + const char **hosts, int host_cont, + struct sockaddr_in *addrs4, struct sockaddr_in6 *addrs6) { + size_t host_idx; + const struct addrinfo *rp; + OSMO_ASSERT(family == AF_INET || family == AF_INET6); + + for (host_idx = 0; host_idx < host_cont; host_idx++) { + for (rp = result[host_idx]; rp != NULL; rp = rp->ai_next) { + if (rp->ai_family != family) + continue; + if (family == AF_INET) + memcpy(&addrs4[host_idx], rp->ai_addr, sizeof(addrs4[host_idx])); + else + memcpy(&addrs6[host_idx], rp->ai_addr, sizeof(addrs6[host_idx])); + break; + } + if (!rp) { /* No addr could be bound for this host! */ + LOGP(DLGLOBAL, LOGL_ERROR, "No suitable remote address found for host: %s\n", + hosts[host_idx]); + return -ENODEV; + } + } + return 0; +} + +/*! Initialize a socket (including bind and/or connect) with multiple local or remote addresses. + * \param[in] family Address Family like AF_INET, AF_INET6, AF_UNSPEC + * \param[in] type Socket type like SOCK_DGRAM, SOCK_STREAM + * \param[in] proto Protocol like IPPROTO_TCP, IPPROTO_UDP + * \param[in] local_hosts array of char pointers (strings), each containing local host name or IP address in string form + * \param[in] local_hosts_cnt length of local_hosts (in items) + * \param[in] local_port local port number in host byte order + * \param[in] remote_host array of char pointers (strings), each containing remote host name or IP address in string form + * \param[in] remote_hosts_cnt length of remote_hosts (in items) + * \param[in] remote_port remote port number in host byte order + * \param[in] flags flags like \ref OSMO_SOCK_F_CONNECT + * \returns socket file descriptor on success; negative on error + * + * This function is similar to \ref osmo_sock_init2(), but can be passed an + * array of local or remote addresses for protocols supporting multiple + * addresses per socket, like SCTP (currently only one supported). This function + * should not be used by protocols not supporting this kind of features, but + * rather \ref osmo_sock_init2() should be used instead. + * See \ref osmo_sock_init2() for more information on flags and general behavior. + */ +int osmo_sock_init2_multiaddr(uint16_t family, uint16_t type, uint8_t proto, + const char **local_hosts, size_t local_hosts_cnt, uint16_t local_port, + const char **remote_hosts, size_t remote_hosts_cnt, uint16_t remote_port, + unsigned int flags) + +{ + struct addrinfo *result[OSMO_SOCK_MAX_ADDRS]; + int sfd = -1, rc, on = 1; + int i; + struct sockaddr_in addrs4[OSMO_SOCK_MAX_ADDRS]; + struct sockaddr_in6 addrs6[OSMO_SOCK_MAX_ADDRS]; + struct sockaddr *addrs; + char strbuf[512]; + + /* TODO: So far this function is only aimed for SCTP, but could be + reused in the future for other protocols with multi-addr support */ + if (proto != IPPROTO_SCTP) + return -ENOTSUP; + + /* TODO: Let's not support AF_UNSPEC for now. sctp_bindx() actually + supports binding both types of addresses on a AF_INET6 soscket, but + that would mean we could get both AF_INET and AF_INET6 addresses for + each host, and makes complexity of this function increase a lot since + we'd need to find out which subsets to use, use v4v6 mapped socket, + etc. */ + if (family == AF_UNSPEC) + return -ENOTSUP; + + if ((flags & (OSMO_SOCK_F_BIND | OSMO_SOCK_F_CONNECT)) == 0) { + LOGP(DLGLOBAL, LOGL_ERROR, "invalid: you have to specify either " + "BIND or CONNECT flags\n"); + return -EINVAL; + } + + if (((flags & OSMO_SOCK_F_BIND) && !local_hosts_cnt) || + ((flags & OSMO_SOCK_F_CONNECT) && !remote_hosts_cnt) || + local_hosts_cnt > OSMO_SOCK_MAX_ADDRS || + remote_hosts_cnt > OSMO_SOCK_MAX_ADDRS) + return -EINVAL; + + /* figure out local side of socket */ + if (flags & OSMO_SOCK_F_BIND) { + rc = addrinfo_helper_multi(result, family, type, proto, local_hosts, + local_hosts_cnt, local_port, true); + if (rc < 0) + return -EINVAL; + + /* Since addrinfo_helper sets ai_family, socktype and + ai_protocol in hints, we know all results will use same + values, so simply pick the first one and pass it to create + the socket: + */ + sfd = socket_helper(result[0], flags); + if (sfd < 0) { + for (i = 0; i < local_hosts_cnt; i++) + freeaddrinfo(result[i]); + return sfd; + } + + if (proto != IPPROTO_UDP || flags & OSMO_SOCK_F_UDP_REUSEADDR) { + rc = setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, + &on, sizeof(on)); + if (rc < 0) { + multiaddr_snprintf(strbuf, sizeof(strbuf), local_hosts, local_hosts_cnt); + LOGP(DLGLOBAL, LOGL_ERROR, + "cannot setsockopt socket:" + " %s:%u: %s\n", + strbuf, local_port, + strerror(errno)); + for (i = 0; i < local_hosts_cnt; i++) + freeaddrinfo(result[i]); + close(sfd); + return rc; + } + } + + /* Build array of addresses taking first of same family for each host. + TODO: Ideally we should use backtracking storing last used + indexes and trying next combination if connect() fails .*/ + rc = addrinfo_to_sockaddr(family, (const struct addrinfo **)result, + local_hosts, local_hosts_cnt, addrs4, addrs6); + if (rc < 0) { + for (i = 0; i < local_hosts_cnt; i++) + freeaddrinfo(result[i]); + close(sfd); + return -ENODEV; + } + + if (family == AF_INET) + addrs = (struct sockaddr *)addrs4; + else + addrs = (struct sockaddr *)addrs6; + if (sctp_bindx(sfd, addrs, local_hosts_cnt, SCTP_BINDX_ADD_ADDR) == -1) { + multiaddr_snprintf(strbuf, sizeof(strbuf), local_hosts, local_hosts_cnt); + LOGP(DLGLOBAL, LOGL_NOTICE, "unable to bind socket: %s:%u: %s\n", + strbuf, local_port, strerror(errno)); + for (i = 0; i < local_hosts_cnt; i++) + freeaddrinfo(result[i]); + close(sfd); + return -ENODEV; + } + for (i = 0; i < local_hosts_cnt; i++) + freeaddrinfo(result[i]); + } + + /* Reached this point, if OSMO_SOCK_F_BIND then sfd is valid (>=0) or it + was already closed and func returned. If OSMO_SOCK_F_BIND is not + set, then sfd = -1 */ + + /* figure out remote side of socket */ + if (flags & OSMO_SOCK_F_CONNECT) { + rc = addrinfo_helper_multi(result, family, type, proto, remote_hosts, + remote_hosts_cnt, remote_port, false); + if (rc < 0) { + if (sfd >= 0) + close(sfd); + return -EINVAL; + } + + if (sfd < 0) { + /* Since addrinfo_helper sets ai_family, socktype and + ai_protocol in hints, we know all results will use same + values, so simply pick the first one and pass it to create + the socket: + */ + sfd = socket_helper(result[0], flags); + if (sfd < 0) { + for (i = 0; i < remote_hosts_cnt; i++) + freeaddrinfo(result[i]); + return sfd; + } + } + + /* Build array of addresses taking first of same family for each host. + TODO: Ideally we should use backtracking storing last used + indexes and trying next combination if connect() fails .*/ + rc = addrinfo_to_sockaddr(family, (const struct addrinfo **)result, + remote_hosts, remote_hosts_cnt, addrs4, addrs6); + if (rc < 0) { + for (i = 0; i < remote_hosts_cnt; i++) + freeaddrinfo(result[i]); + close(sfd); + return -ENODEV; + } + + if (family == AF_INET) + addrs = (struct sockaddr *)addrs4; + else + addrs = (struct sockaddr *)addrs6; + rc = sctp_connectx(sfd, addrs, remote_hosts_cnt, NULL); + if (rc != 0 && errno != EINPROGRESS) { + multiaddr_snprintf(strbuf, sizeof(strbuf), remote_hosts, remote_hosts_cnt); + LOGP(DLGLOBAL, LOGL_ERROR, "unable to connect socket: %s:%u: %s\n", + strbuf, remote_port, strerror(errno)); + for (i = 0; i < remote_hosts_cnt; i++) + freeaddrinfo(result[i]); + close(sfd); + return -ENODEV; + } + for (i = 0; i < remote_hosts_cnt; i++) + freeaddrinfo(result[i]); + } + + rc = osmo_sock_init_tail(sfd, type, flags); + if (rc < 0) { + close(sfd); + sfd = -1; + } + + return sfd; +} +#endif /* HAVE_LIBSCTP */ /*! Initialize a socket (including bind/connect) * \param[in] family Address Family like AF_INET, AF_INET6, AF_UNSPEC -- cgit v1.2.3