diff options
Diffstat (limited to 'unix/network.c')
| -rw-r--r-- | unix/network.c | 1755 |
1 files changed, 1755 insertions, 0 deletions
diff --git a/unix/network.c b/unix/network.c new file mode 100644 index 00000000..31c754bd --- /dev/null +++ b/unix/network.c @@ -0,0 +1,1755 @@ +/* + * Unix networking abstraction. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <assert.h> +#include <errno.h> +#include <fcntl.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/ioctl.h> +#include <arpa/inet.h> +#include <netinet/in.h> +#include <netinet/tcp.h> +#include <netdb.h> +#include <sys/un.h> +#include <pwd.h> +#include <grp.h> + +#include "putty.h" +#include "network.h" +#include "tree234.h" + +/* Solaris needs <sys/sockio.h> for SIOCATMARK. */ +#ifndef SIOCATMARK +#include <sys/sockio.h> +#endif + +#ifndef X11_UNIX_PATH +# define X11_UNIX_PATH "/tmp/.X11-unix/X" +#endif + +/* + * Access to sockaddr types without breaking C strict aliasing rules. + */ +union sockaddr_union { + struct sockaddr_storage storage; + struct sockaddr sa; + struct sockaddr_in sin; +#ifndef NO_IPV6 + struct sockaddr_in6 sin6; +#endif + struct sockaddr_un su; +}; + +/* + * Mutable state that goes with a SockAddr: stores information + * about where in the list of candidate IP(v*) addresses we've + * currently got to. + */ +typedef struct SockAddrStep_tag SockAddrStep; +struct SockAddrStep_tag { +#ifndef NO_IPV6 + struct addrinfo *ai; /* steps along addr->ais */ +#endif + int curraddr; +}; + +typedef struct NetSocket NetSocket; +struct NetSocket { + const char *error; + int s; + Plug *plug; + bufchain output_data; + bool connected; /* irrelevant for listening sockets */ + bool writable; + bool frozen; /* this causes readability notifications to be ignored */ + bool localhost_only; /* for listening sockets */ + char oobdata[1]; + size_t sending_oob; + bool oobpending; /* is there OOB data available to read? */ + bool oobinline; + enum { EOF_NO, EOF_PENDING, EOF_SENT } outgoingeof; + bool incomingeof; + int pending_error; /* in case send() returns error */ + bool listener; + bool nodelay, keepalive; /* for connect()-type sockets */ + bool privport; + int port; /* and again */ + SockAddr *addr; + SockAddrStep step; + /* + * We sometimes need pairs of Socket structures to be linked: + * if we are listening on the same IPv6 and v4 port, for + * example. So here we define `parent' and `child' pointers to + * track this link. + */ + NetSocket *parent, *child; + + Socket sock; +}; + +struct SockAddr { + int refcount; + const char *error; + enum { UNRESOLVED, UNIX, IP } superfamily; +#ifndef NO_IPV6 + struct addrinfo *ais; /* Addresses IPv6 style. */ +#else + unsigned long *addresses; /* Addresses IPv4 style. */ + int naddresses; +#endif + char hostname[512]; /* Store an unresolved host name. */ +}; + +/* + * Which address family this address belongs to. AF_INET for IPv4; + * AF_INET6 for IPv6; AF_UNSPEC indicates that name resolution has + * not been done and a simple host name is held in this SockAddr + * structure. + */ +#ifndef NO_IPV6 +#define SOCKADDR_FAMILY(addr, step) \ + ((addr)->superfamily == UNRESOLVED ? AF_UNSPEC : \ + (addr)->superfamily == UNIX ? AF_UNIX : \ + (step).ai ? (step).ai->ai_family : AF_INET) +#else +/* Here we gratuitously reference 'step' to avoid gcc warnings about + * 'set but not used' when compiling -DNO_IPV6 */ +#define SOCKADDR_FAMILY(addr, step) \ + ((addr)->superfamily == UNRESOLVED ? AF_UNSPEC : \ + (addr)->superfamily == UNIX ? AF_UNIX : \ + (step).curraddr ? AF_INET : AF_INET) +#endif + +/* + * Start a SockAddrStep structure to step through multiple + * addresses. + */ +#ifndef NO_IPV6 +#define START_STEP(addr, step) \ + ((step).ai = (addr)->ais, (step).curraddr = 0) +#else +#define START_STEP(addr, step) \ + ((step).curraddr = 0) +#endif + +static tree234 *sktree; + +static void uxsel_tell(NetSocket *s); + +static int cmpfortree(void *av, void *bv) +{ + NetSocket *a = (NetSocket *) av, *b = (NetSocket *) bv; + int as = a->s, bs = b->s; + if (as < bs) + return -1; + if (as > bs) + return +1; + if (a < b) + return -1; + if (a > b) + return +1; + return 0; +} + +static int cmpforsearch(void *av, void *bv) +{ + NetSocket *b = (NetSocket *) bv; + int as = *(int *)av, bs = b->s; + if (as < bs) + return -1; + if (as > bs) + return +1; + return 0; +} + +void sk_init(void) +{ + sktree = newtree234(cmpfortree); +} + +void sk_cleanup(void) +{ + NetSocket *s; + int i; + + if (sktree) { + for (i = 0; (s = index234(sktree, i)) != NULL; i++) { + close(s->s); + } + } +} + +SockAddr *sk_namelookup(const char *host, char **canonicalname, + int address_family) +{ + *canonicalname = NULL; + + if (host[0] == '/') { + *canonicalname = dupstr(host); + return unix_sock_addr(host); + } + + SockAddr *addr = snew(SockAddr); + memset(addr, 0, sizeof(SockAddr)); + addr->superfamily = UNRESOLVED; + addr->refcount = 1; + +#ifndef NO_IPV6 + /* + * Use getaddrinfo, as long as it's available. This should handle + * both IPv4 and IPv6 address literals, and hostnames, in one + * unified API. + */ + { + struct addrinfo hints; + memset(&hints, 0, sizeof(hints)); + hints.ai_family = (address_family == ADDRTYPE_IPV4 ? AF_INET : + address_family == ADDRTYPE_IPV6 ? AF_INET6 : + AF_UNSPEC); + hints.ai_flags = AI_CANONNAME; + hints.ai_socktype = SOCK_STREAM; + + /* strip [] on IPv6 address literals */ + char *trimmed_host = host_strduptrim(host); + int err = getaddrinfo(trimmed_host, NULL, &hints, &addr->ais); + sfree(trimmed_host); + + if (addr->ais) { + addr->superfamily = IP; + if (addr->ais->ai_canonname) + *canonicalname = dupstr(addr->ais->ai_canonname); + else + *canonicalname = dupstr(host); + } else { + addr->error = gai_strerror(err); + } + return addr; + } + +#else + /* + * Failing that (if IPv6 support was not compiled in), try the + * old-fashioned approach, which is to start by manually checking + * for an IPv4 literal and then use gethostbyname. + */ + unsigned long a = inet_addr(host); + if (a != (unsigned long) INADDR_NONE) { + addr->addresses = snew(unsigned long); + addr->naddresses = 1; + addr->addresses[0] = ntohl(a); + addr->superfamily = IP; + *canonicalname = dupstr(host); + return addr; + } + + struct hostent *h = gethostbyname(host); + if (h) { + addr->superfamily = IP; + + size_t n; + for (n = 0; h->h_addr_list[n]; n++); + addr->addresses = snewn(n, unsigned long); + addr->naddresses = n; + for (n = 0; n < addr->naddresses; n++) { + uint32_t a; + memcpy(&a, h->h_addr_list[n], sizeof(a)); + addr->addresses[n] = ntohl(a); + } + + *canonicalname = dupstr(h->h_name); + } else { + addr->error = hstrerror(h_errno); + } + return addr; +#endif +} + +SockAddr *sk_nonamelookup(const char *host) +{ + SockAddr *ret = snew(SockAddr); + ret->error = NULL; + ret->superfamily = UNRESOLVED; + strncpy(ret->hostname, host, lenof(ret->hostname)); + ret->hostname[lenof(ret->hostname)-1] = '\0'; +#ifndef NO_IPV6 + ret->ais = NULL; +#else + ret->addresses = NULL; +#endif + ret->refcount = 1; + return ret; +} + +static bool sk_nextaddr(SockAddr *addr, SockAddrStep *step) +{ +#ifndef NO_IPV6 + if (step->ai && step->ai->ai_next) { + step->ai = step->ai->ai_next; + return true; + } else + return false; +#else + if (step->curraddr+1 < addr->naddresses) { + step->curraddr++; + return true; + } else { + return false; + } +#endif +} + +void sk_getaddr(SockAddr *addr, char *buf, int buflen) +{ + if (addr->superfamily == UNRESOLVED || addr->superfamily == UNIX) { + strncpy(buf, addr->hostname, buflen); + buf[buflen-1] = '\0'; + } else { +#ifndef NO_IPV6 + if (getnameinfo(addr->ais->ai_addr, addr->ais->ai_addrlen, buf, buflen, + NULL, 0, NI_NUMERICHOST) != 0) { + buf[0] = '\0'; + strncat(buf, "<unknown>", buflen - 1); + } +#else + struct in_addr a; + SockAddrStep step; + START_STEP(addr, step); + assert(SOCKADDR_FAMILY(addr, step) == AF_INET); + a.s_addr = htonl(addr->addresses[0]); + strncpy(buf, inet_ntoa(a), buflen); + buf[buflen-1] = '\0'; +#endif + } +} + +/* + * This constructs a SockAddr that points at one specific sub-address + * of a parent SockAddr. The returned SockAddr does not own all its + * own memory: it points into the old one's data structures, so it + * MUST NOT be used after the old one is freed, and it MUST NOT be + * passed to sk_addr_free. (The latter is why it's returned by value + * rather than dynamically allocated - that should clue in anyone + * writing a call to it that something is weird about it.) + */ +static SockAddr sk_extractaddr_tmp( + SockAddr *addr, const SockAddrStep *step) +{ + SockAddr toret; + toret = *addr; /* structure copy */ + toret.refcount = 1; + + if (addr->superfamily == IP) { +#ifndef NO_IPV6 + toret.ais = step->ai; +#else + assert(SOCKADDR_FAMILY(addr, *step) == AF_INET); + toret.addresses += step->curraddr; +#endif + } + + return toret; +} + +bool sk_addr_needs_port(SockAddr *addr) +{ + if (addr->superfamily == UNRESOLVED || addr->superfamily == UNIX) { + return false; + } else { + return true; + } +} + +bool sk_hostname_is_local(const char *name) +{ + return !strcmp(name, "localhost") || + !strcmp(name, "::1") || + !strncmp(name, "127.", 4); +} + +#define ipv4_is_loopback(addr) \ + (((addr).s_addr & htonl(0xff000000)) == htonl(0x7f000000)) + +static bool sockaddr_is_loopback(struct sockaddr *sa) +{ + union sockaddr_union *u = (union sockaddr_union *)sa; + switch (u->sa.sa_family) { + case AF_INET: + return ipv4_is_loopback(u->sin.sin_addr); +#ifndef NO_IPV6 + case AF_INET6: + return IN6_IS_ADDR_LOOPBACK(&u->sin6.sin6_addr); +#endif + case AF_UNIX: + return true; + default: + return false; + } +} + +bool sk_address_is_local(SockAddr *addr) +{ + if (addr->superfamily == UNRESOLVED) + return false; /* we don't know; assume not */ + else if (addr->superfamily == UNIX) + return true; + else { +#ifndef NO_IPV6 + return sockaddr_is_loopback(addr->ais->ai_addr); +#else + struct in_addr a; + SockAddrStep step; + START_STEP(addr, step); + assert(SOCKADDR_FAMILY(addr, step) == AF_INET); + a.s_addr = htonl(addr->addresses[0]); + return ipv4_is_loopback(a); +#endif + } +} + +bool sk_address_is_special_local(SockAddr *addr) +{ + return addr->superfamily == UNIX; +} + +int sk_addrtype(SockAddr *addr) +{ + SockAddrStep step; + int family; + START_STEP(addr, step); + family = SOCKADDR_FAMILY(addr, step); + + return (family == AF_INET ? ADDRTYPE_IPV4 : +#ifndef NO_IPV6 + family == AF_INET6 ? ADDRTYPE_IPV6 : +#endif + ADDRTYPE_NAME); +} + +void sk_addrcopy(SockAddr *addr, char *buf) +{ + SockAddrStep step; + int family; + START_STEP(addr, step); + family = SOCKADDR_FAMILY(addr, step); + +#ifndef NO_IPV6 + if (family == AF_INET) + memcpy(buf, &((struct sockaddr_in *)step.ai->ai_addr)->sin_addr, + sizeof(struct in_addr)); + else if (family == AF_INET6) + memcpy(buf, &((struct sockaddr_in6 *)step.ai->ai_addr)->sin6_addr, + sizeof(struct in6_addr)); + else + unreachable("bad address family in sk_addrcopy"); +#else + struct in_addr a; + + assert(family == AF_INET); + a.s_addr = htonl(addr->addresses[step.curraddr]); + memcpy(buf, (char*) &a.s_addr, 4); +#endif +} + +void sk_addr_free(SockAddr *addr) +{ + if (--addr->refcount > 0) + return; +#ifndef NO_IPV6 + if (addr->ais != NULL) + freeaddrinfo(addr->ais); +#else + sfree(addr->addresses); +#endif + sfree(addr); +} + +SockAddr *sk_addr_dup(SockAddr *addr) +{ + addr->refcount++; + return addr; +} + +static Plug *sk_net_plug(Socket *sock, Plug *p) +{ + NetSocket *s = container_of(sock, NetSocket, sock); + Plug *ret = s->plug; + if (p) + s->plug = p; + return ret; +} + +static void sk_net_close(Socket *s); +static size_t sk_net_write(Socket *s, const void *data, size_t len); +static size_t sk_net_write_oob(Socket *s, const void *data, size_t len); +static void sk_net_write_eof(Socket *s); +static void sk_net_set_frozen(Socket *s, bool is_frozen); +static SocketPeerInfo *sk_net_peer_info(Socket *s); +static const char *sk_net_socket_error(Socket *s); + +static const SocketVtable NetSocket_sockvt = { + .plug = sk_net_plug, + .close = sk_net_close, + .write = sk_net_write, + .write_oob = sk_net_write_oob, + .write_eof = sk_net_write_eof, + .set_frozen = sk_net_set_frozen, + .socket_error = sk_net_socket_error, + .peer_info = sk_net_peer_info, +}; + +static Socket *sk_net_accept(accept_ctx_t ctx, Plug *plug) +{ + int sockfd = ctx.i; + NetSocket *ret; + + /* + * Create NetSocket structure. + */ + ret = snew(NetSocket); + ret->sock.vt = &NetSocket_sockvt; + ret->error = NULL; + ret->plug = plug; + bufchain_init(&ret->output_data); + ret->writable = true; /* to start with */ + ret->sending_oob = 0; + ret->frozen = true; + ret->localhost_only = false; /* unused, but best init anyway */ + ret->pending_error = 0; + ret->oobpending = false; + ret->outgoingeof = EOF_NO; + ret->incomingeof = false; + ret->listener = false; + ret->parent = ret->child = NULL; + ret->addr = NULL; + ret->connected = true; + + ret->s = sockfd; + + if (ret->s < 0) { + ret->error = strerror(errno); + return &ret->sock; + } + + ret->oobinline = false; + + uxsel_tell(ret); + add234(sktree, ret); + + return &ret->sock; +} + +static int try_connect(NetSocket *sock) +{ + int s; + union sockaddr_union u; + const union sockaddr_union *sa; + int err = 0; + short localport; + int salen, family; + + /* + * Remove the socket from the tree before we overwrite its + * internal socket id, because that forms part of the tree's + * sorting criterion. We'll add it back before exiting this + * function, whether we changed anything or not. + */ + del234(sktree, sock); + + if (sock->s >= 0) + close(sock->s); + + { + SockAddr thisaddr = sk_extractaddr_tmp( + sock->addr, &sock->step); + plug_log(sock->plug, PLUGLOG_CONNECT_TRYING, + &thisaddr, sock->port, NULL, 0); + } + + /* + * Open socket. + */ + family = SOCKADDR_FAMILY(sock->addr, sock->step); + assert(family != AF_UNSPEC); + s = socket(family, SOCK_STREAM, 0); + sock->s = s; + + if (s < 0) { + err = errno; + goto ret; + } + + cloexec(s); + + if (sock->oobinline) { + int b = 1; + if (setsockopt(s, SOL_SOCKET, SO_OOBINLINE, + (void *) &b, sizeof(b)) < 0) { + err = errno; + close(s); + goto ret; + } + } + + if (sock->nodelay && family != AF_UNIX) { + int b = 1; + if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY, + (void *) &b, sizeof(b)) < 0) { + err = errno; + close(s); + goto ret; + } + } + + if (sock->keepalive) { + int b = 1; + if (setsockopt(s, SOL_SOCKET, SO_KEEPALIVE, + (void *) &b, sizeof(b)) < 0) { + err = errno; + close(s); + goto ret; + } + } + + /* + * Bind to local address. + */ + if (sock->privport) + localport = 1023; /* count from 1023 downwards */ + else + localport = 0; /* just use port 0 (ie kernel picks) */ + + /* BSD IP stacks need sockaddr_in zeroed before filling in */ + memset(&u,'\0',sizeof(u)); + + /* We don't try to bind to a local address for UNIX domain sockets. (Why + * do we bother doing the bind when localport == 0 anyway?) */ + if (family != AF_UNIX) { + /* Loop round trying to bind */ + while (1) { + int retcode; + +#ifndef NO_IPV6 + if (family == AF_INET6) { + /* XXX use getaddrinfo to get a local address? */ + u.sin6.sin6_family = AF_INET6; + u.sin6.sin6_addr = in6addr_any; + u.sin6.sin6_port = htons(localport); + retcode = bind(s, &u.sa, sizeof(u.sin6)); + } else +#endif + { + assert(family == AF_INET); + u.sin.sin_family = AF_INET; + u.sin.sin_addr.s_addr = htonl(INADDR_ANY); + u.sin.sin_port = htons(localport); + retcode = bind(s, &u.sa, sizeof(u.sin)); + } + if (retcode >= 0) { + err = 0; + break; /* done */ + } else { + err = errno; + if (err != EADDRINUSE) /* failed, for a bad reason */ + break; + } + + if (localport == 0) + break; /* we're only looping once */ + localport--; + if (localport == 0) + break; /* we might have got to the end */ + } + + if (err) + goto ret; + } + + /* + * Connect to remote address. + */ + switch(family) { +#ifndef NO_IPV6 + case AF_INET: + /* XXX would be better to have got getaddrinfo() to fill in the port. */ + ((struct sockaddr_in *)sock->step.ai->ai_addr)->sin_port = + htons(sock->port); + sa = (const union sockaddr_union *)sock->step.ai->ai_addr; + salen = sock->step.ai->ai_addrlen; + break; + case AF_INET6: + ((struct sockaddr_in *)sock->step.ai->ai_addr)->sin_port = + htons(sock->port); + sa = (const union sockaddr_union *)sock->step.ai->ai_addr; + salen = sock->step.ai->ai_addrlen; + break; +#else + case AF_INET: + u.sin.sin_family = AF_INET; + u.sin.sin_addr.s_addr = htonl(sock->addr->addresses[sock->step.curraddr]); + u.sin.sin_port = htons((short) sock->port); + sa = &u; + salen = sizeof u.sin; + break; +#endif + case AF_UNIX: + assert(strlen(sock->addr->hostname) < sizeof u.su.sun_path); + u.su.sun_family = AF_UNIX; + strcpy(u.su.sun_path, sock->addr->hostname); + sa = &u; + salen = sizeof u.su; + break; + + default: + unreachable("unknown address family"); + exit(1); /* XXX: GCC doesn't understand assert() on some systems. */ + } + + nonblock(s); + + if ((connect(s, &(sa->sa), salen)) < 0) { + if ( errno != EINPROGRESS ) { + err = errno; + goto ret; + } + } else { + /* + * If we _don't_ get EWOULDBLOCK, the connect has completed + * and we should set the socket as connected and writable. + */ + sock->connected = true; + sock->writable = true; + + SockAddr thisaddr = sk_extractaddr_tmp(sock->addr, &sock->step); + plug_log(sock->plug, PLUGLOG_CONNECT_SUCCESS, + &thisaddr, sock->port, NULL, 0); + } + + uxsel_tell(sock); + + ret: + + /* + * No matter what happened, put the socket back in the tree. + */ + add234(sktree, sock); + + if (err) { + SockAddr thisaddr = sk_extractaddr_tmp( + sock->addr, &sock->step); + plug_log(sock->plug, PLUGLOG_CONNECT_FAILED, + &thisaddr, sock->port, strerror(err), err); + } + return err; +} + +Socket *sk_new(SockAddr *addr, int port, bool privport, bool oobinline, + bool nodelay, bool keepalive, Plug *plug) +{ + NetSocket *ret; + int err; + + /* + * Create NetSocket structure. + */ + ret = snew(NetSocket); + ret->sock.vt = &NetSocket_sockvt; + ret->error = NULL; + ret->plug = plug; + bufchain_init(&ret->output_data); + ret->connected = false; /* to start with */ + ret->writable = false; /* to start with */ + ret->sending_oob = 0; + ret->frozen = false; + ret->localhost_only = false; /* unused, but best init anyway */ + ret->pending_error = 0; + ret->parent = ret->child = NULL; + ret->oobpending = false; + ret->outgoingeof = EOF_NO; + ret->incomingeof = false; + ret->listener = false; + ret->addr = addr; + START_STEP(ret->addr, ret->step); + ret->s = -1; + ret->oobinline = oobinline; + ret->nodelay = nodelay; + ret->keepalive = keepalive; + ret->privport = privport; + ret->port = port; + + do { + err = try_connect(ret); + } while (err && sk_nextaddr(ret->addr, &ret->step)); + + if (err) + ret->error = strerror(err); + + return &ret->sock; +} + +Socket *sk_newlistener(const char *srcaddr, int port, Plug *plug, + bool local_host_only, int orig_address_family) +{ + int s; +#ifndef NO_IPV6 + struct addrinfo hints, *ai = NULL; + char portstr[6]; +#endif + union sockaddr_union u; + union sockaddr_union *addr; + int addrlen; + NetSocket *ret; + int retcode; + int address_family; + int on = 1; + + /* + * Create NetSocket structure. + */ + ret = snew(NetSocket); + ret->sock.vt = &NetSocket_sockvt; + ret->error = NULL; + ret->plug = plug; + bufchain_init(&ret->output_data); + ret->writable = false; /* to start with */ + ret->sending_oob = 0; + ret->frozen = false; + ret->localhost_only = local_host_only; + ret->pending_error = 0; + ret->parent = ret->child = NULL; + ret->oobpending = false; + ret->outgoingeof = EOF_NO; + ret->incomingeof = false; + ret->listener = true; + ret->addr = NULL; + ret->s = -1; + + /* + * Translate address_family from platform-independent constants + * into local reality. + */ + address_family = (orig_address_family == ADDRTYPE_IPV4 ? AF_INET : +#ifndef NO_IPV6 + orig_address_family == ADDRTYPE_IPV6 ? AF_INET6 : +#endif + AF_UNSPEC); + +#ifndef NO_IPV6 + /* Let's default to IPv6. + * If the stack doesn't support IPv6, we will fall back to IPv4. */ + if (address_family == AF_UNSPEC) address_family = AF_INET6; +#else + /* No other choice, default to IPv4 */ + if (address_family == AF_UNSPEC) address_family = AF_INET; +#endif + + /* + * Open socket. + */ + s = socket(address_family, SOCK_STREAM, 0); + +#ifndef NO_IPV6 + /* If the host doesn't support IPv6 try fallback to IPv4. */ + if (s < 0 && address_family == AF_INET6) { + address_family = AF_INET; + s = socket(address_family, SOCK_STREAM, 0); + } +#endif + + if (s < 0) { + ret->error = strerror(errno); + return &ret->sock; + } + + cloexec(s); + + ret->oobinline = false; + + if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, + (const char *)&on, sizeof(on)) < 0) { + ret->error = strerror(errno); + close(s); + return &ret->sock; + } + + retcode = -1; + addr = NULL; addrlen = -1; /* placate optimiser */ + + if (srcaddr != NULL) { +#ifndef NO_IPV6 + hints.ai_flags = AI_NUMERICHOST; + hints.ai_family = address_family; + hints.ai_socktype = SOCK_STREAM; + hints.ai_protocol = 0; + hints.ai_addrlen = 0; + hints.ai_addr = NULL; + hints.ai_canonname = NULL; + hints.ai_next = NULL; + assert(port >= 0 && port <= 99999); + sprintf(portstr, "%d", port); + { + char *trimmed_addr = host_strduptrim(srcaddr); + retcode = getaddrinfo(trimmed_addr, portstr, &hints, &ai); + sfree(trimmed_addr); + } + if (retcode == 0) { + addr = (union sockaddr_union *)ai->ai_addr; + addrlen = ai->ai_addrlen; + } +#else + memset(&u,'\0',sizeof u); + u.sin.sin_family = AF_INET; + u.sin.sin_port = htons(port); + u.sin.sin_addr.s_addr = inet_addr(srcaddr); + if (u.sin.sin_addr.s_addr != (in_addr_t)(-1)) { + /* Override localhost_only with specified listen addr. */ + ret->localhost_only = ipv4_is_loopback(u.sin.sin_addr); + } + addr = &u; + addrlen = sizeof(u.sin); + retcode = 0; +#endif + } + + if (retcode != 0) { + memset(&u,'\0',sizeof u); +#ifndef NO_IPV6 + if (address_family == AF_INET6) { + u.sin6.sin6_family = AF_INET6; + u.sin6.sin6_port = htons(port); + if (local_host_only) + u.sin6.sin6_addr = in6addr_loopback; + else + u.sin6.sin6_addr = in6addr_any; + addr = &u; + addrlen = sizeof(u.sin6); + } else +#endif + { + u.sin.sin_family = AF_INET; + u.sin.sin_port = htons(port); + if (local_host_only) + u.sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK); + else + u.sin.sin_addr.s_addr = htonl(INADDR_ANY); + addr = &u; + addrlen = sizeof(u.sin); + } + } + + retcode = bind(s, &addr->sa, addrlen); + +#ifndef NO_IPV6 + if (ai) + freeaddrinfo(ai); +#endif + + if (retcode < 0) { + close(s); + ret->error = strerror(errno); + return &ret->sock; + } + + if (listen(s, SOMAXCONN) < 0) { + close(s); + ret->error = strerror(errno); + return &ret->sock; + } + +#ifndef NO_IPV6 + /* + * If we were given ADDRTYPE_UNSPEC, we must also create an + * IPv4 listening socket and link it to this one. + */ + if (address_family == AF_INET6 && orig_address_family == ADDRTYPE_UNSPEC) { + NetSocket *other; + + other = container_of( + sk_newlistener(srcaddr, port, plug, + local_host_only, ADDRTYPE_IPV4), + NetSocket, sock); + + if (other) { + if (!other->error) { + other->parent = ret; + ret->child = other; + } else { + /* If we couldn't create a listening socket on IPv4 as well + * as IPv6, we must return an error overall. */ + close(s); + sfree(ret); + return &other->sock; + } + } + } +#endif + + ret->s = s; + + uxsel_tell(ret); + add234(sktree, ret); + + return &ret->sock; +} + +static void sk_net_close(Socket *sock) +{ + NetSocket *s = container_of(sock, NetSocket, sock); + + if (s->child) + sk_net_close(&s->child->sock); + + bufchain_clear(&s->output_data); + + del234(sktree, s); + if (s->s >= 0) { + uxsel_del(s->s); + close(s->s); + } + if (s->addr) + sk_addr_free(s->addr); + delete_callbacks_for_context(s); + sfree(s); +} + +void *sk_getxdmdata(Socket *sock, int *lenp) +{ + NetSocket *s; + union sockaddr_union u; + socklen_t addrlen; + char *buf; + static unsigned int unix_addr = 0xFFFFFFFF; + + /* + * We must check that this socket really _is_ a NetSocket before + * downcasting it. + */ + if (sock->vt != &NetSocket_sockvt) + return NULL; /* failure */ + s = container_of(sock, NetSocket, sock); + + addrlen = sizeof(u); + if (getsockname(s->s, &u.sa, &addrlen) < 0) + return NULL; + switch(u.sa.sa_family) { + case AF_INET: + *lenp = 6; + buf = snewn(*lenp, char); + PUT_32BIT_MSB_FIRST(buf, ntohl(u.sin.sin_addr.s_addr)); + PUT_16BIT_MSB_FIRST(buf+4, ntohs(u.sin.sin_port)); + break; +#ifndef NO_IPV6 + case AF_INET6: + *lenp = 6; + buf = snewn(*lenp, char); + if (IN6_IS_ADDR_V4MAPPED(&u.sin6.sin6_addr)) { + memcpy(buf, u.sin6.sin6_addr.s6_addr + 12, 4); + PUT_16BIT_MSB_FIRST(buf+4, ntohs(u.sin6.sin6_port)); + } else + /* This is stupid, but it's what XLib does. */ + memset(buf, 0, 6); + break; +#endif + case AF_UNIX: + *lenp = 6; + buf = snewn(*lenp, char); + PUT_32BIT_MSB_FIRST(buf, unix_addr--); + PUT_16BIT_MSB_FIRST(buf+4, getpid()); + break; + + /* XXX IPV6 */ + + default: + return NULL; + } + + return buf; +} + +void plug_closing_errno(Plug *plug, int error) +{ + PlugCloseType type = PLUGCLOSE_ERROR; + if (error == EPIPE) + type = PLUGCLOSE_BROKEN_PIPE; + plug_closing(plug, type, strerror(error)); +} + +/* + * Deal with socket errors detected in try_send(). + */ +static void socket_error_callback(void *vs) +{ + NetSocket *s = (NetSocket *)vs; + + /* + * Just in case other socket work has caused this socket to vanish + * or become somehow non-erroneous before this callback arrived... + */ + if (!find234(sktree, s, NULL) || !s->pending_error) + return; + + /* + * An error has occurred on this socket. Pass it to the plug. + */ + plug_closing_errno(s->plug, s->pending_error); +} + +/* + * The function which tries to send on a socket once it's deemed + * writable. + */ +void try_send(NetSocket *s) +{ + while (s->sending_oob || bufchain_size(&s->output_data) > 0) { + int nsent; + int err; + const void *data; + size_t len; + int urgentflag; + + if (s->sending_oob) { + urgentflag = MSG_OOB; + len = s->sending_oob; + data = &s->oobdata; + } else { + urgentflag = 0; + ptrlen bufdata = bufchain_prefix(&s->output_data); + data = bufdata.ptr; + len = bufdata.len; + } + nsent = send(s->s, data, len, urgentflag); + noise_ultralight(NOISE_SOURCE_IOLEN, nsent); + if (nsent <= 0) { + err = (nsent < 0 ? errno : 0); + if (err == EWOULDBLOCK) { + /* + * Perfectly normal: we've sent all we can for the moment. + */ + s->writable = false; + return; + } else { + /* + * We unfortunately can't just call plug_closing(), + * because it's quite likely that we're currently + * _in_ a call from the code we'd be calling back + * to, so we'd have to make half the SSH code + * reentrant. Instead we flag a pending error on + * the socket, to be dealt with (by calling + * plug_closing()) at some suitable future moment. + */ + s->pending_error = err; + /* + * Immediately cease selecting on this socket, so that + * we don't tight-loop repeatedly trying to do + * whatever it was that went wrong. + */ + uxsel_tell(s); + /* + * Arrange to be called back from the top level to + * deal with the error condition on this socket. + */ + queue_toplevel_callback(socket_error_callback, s); + return; + } + } else { + if (s->sending_oob) { + if (nsent < len) { + memmove(s->oobdata, s->oobdata+nsent, len-nsent); + s->sending_oob = len - nsent; + } else { + s->sending_oob = 0; + } + } else { + bufchain_consume(&s->output_data, nsent); + } + } + } + + /* + * If we reach here, we've finished sending everything we might + * have needed to send. Send EOF, if we need to. + */ + if (s->outgoingeof == EOF_PENDING) { + shutdown(s->s, SHUT_WR); + s->outgoingeof = EOF_SENT; + } + + /* + * Also update the select status, because we don't need to select + * for writing any more. + */ + uxsel_tell(s); +} + +static size_t sk_net_write(Socket *sock, const void *buf, size_t len) +{ + NetSocket *s = container_of(sock, NetSocket, sock); + + assert(s->outgoingeof == EOF_NO); + + /* + * Add the data to the buffer list on the socket. + */ + bufchain_add(&s->output_data, buf, len); + + /* + * Now try sending from the start of the buffer list. + */ + if (s->writable) + try_send(s); + + /* + * Update the select() status to correctly reflect whether or + * not we should be selecting for write. + */ + uxsel_tell(s); + + return bufchain_size(&s->output_data); +} + +static size_t sk_net_write_oob(Socket *sock, const void *buf, size_t len) +{ + NetSocket *s = container_of(sock, NetSocket, sock); + + assert(s->outgoingeof == EOF_NO); + + /* + * Replace the buffer list on the socket with the data. + */ + bufchain_clear(&s->output_data); + assert(len <= sizeof(s->oobdata)); + memcpy(s->oobdata, buf, len); + s->sending_oob = len; + + /* + * Now try sending from the start of the buffer list. + */ + if (s->writable) + try_send(s); + + /* + * Update the select() status to correctly reflect whether or + * not we should be selecting for write. + */ + uxsel_tell(s); + + return s->sending_oob; +} + +static void sk_net_write_eof(Socket *sock) +{ + NetSocket *s = container_of(sock, NetSocket, sock); + + assert(s->outgoingeof == EOF_NO); + + /* + * Mark the socket as pending outgoing EOF. + */ + s->outgoingeof = EOF_PENDING; + + /* + * Now try sending from the start of the buffer list. + */ + if (s->writable) + try_send(s); + + /* + * Update the select() status to correctly reflect whether or + * not we should be selecting for write. + */ + uxsel_tell(s); +} + +static void net_select_result(int fd, int event) +{ + int ret; + char buf[20480]; /* nice big buffer for plenty of speed */ + NetSocket *s; + bool atmark = true; + + /* Find the Socket structure */ + s = find234(sktree, &fd, cmpforsearch); + if (!s) + return; /* boggle */ + + noise_ultralight(NOISE_SOURCE_IOID, fd); + + switch (event) { + case SELECT_X: /* exceptional */ + if (!s->oobinline) { + /* + * On a non-oobinline socket, this indicates that we + * can immediately perform an OOB read and get back OOB + * data, which we will send to the back end with + * type==2 (urgent data). + */ + ret = recv(s->s, buf, sizeof(buf), MSG_OOB); + noise_ultralight(NOISE_SOURCE_IOLEN, ret); + if (ret == 0) { + plug_closing_error(s->plug, "Internal networking trouble"); + } else if (ret < 0) { + plug_closing_errno(s->plug, errno); + } else { + /* + * Receiving actual data on a socket means we can + * stop falling back through the candidate + * addresses to connect to. + */ + if (s->addr) { + sk_addr_free(s->addr); + s->addr = NULL; + } + plug_receive(s->plug, 2, buf, ret); + } + break; + } + + /* + * If we reach here, this is an oobinline socket, which + * means we should set s->oobpending and then deal with it + * when we get called for the readability event (which + * should also occur). + */ + s->oobpending = true; + break; + case SELECT_R: /* readable; also acceptance */ + if (s->listener) { + /* + * On a listening socket, the readability event means a + * connection is ready to be accepted. + */ + union sockaddr_union su; + socklen_t addrlen = sizeof(su); + accept_ctx_t actx; + int t; /* socket of connection */ + + memset(&su, 0, addrlen); + t = accept(s->s, &su.sa, &addrlen); + if (t < 0) { + break; + } + + nonblock(t); + actx.i = t; + + if ((!s->addr || s->addr->superfamily != UNIX) && + s->localhost_only && !sockaddr_is_loopback(&su.sa)) { + close(t); /* someone let nonlocal through?! */ + } else if (plug_accepting(s->plug, sk_net_accept, actx)) { + close(t); /* denied or error */ + } + break; + } + + /* + * If we reach here, this is not a listening socket, so + * readability really means readability. + */ + + /* In the case the socket is still frozen, we don't even bother */ + if (s->frozen) + break; + + /* + * We have received data on the socket. For an oobinline + * socket, this might be data _before_ an urgent pointer, + * in which case we send it to the back end with type==1 + * (data prior to urgent). + */ + if (s->oobinline && s->oobpending) { + int atmark_from_ioctl; + if (ioctl(s->s, SIOCATMARK, &atmark_from_ioctl) == 0) { + atmark = atmark_from_ioctl; + if (atmark) + s->oobpending = false; /* clear this indicator */ + } + } else + atmark = true; + + ret = recv(s->s, buf, s->oobpending ? 1 : sizeof(buf), 0); + noise_ultralight(NOISE_SOURCE_IOLEN, ret); + if (ret < 0) { + if (errno == EWOULDBLOCK) { + break; + } + } + if (ret < 0) { + plug_closing_errno(s->plug, errno); + } else if (0 == ret) { + s->incomingeof = true; /* stop trying to read now */ + uxsel_tell(s); + plug_closing_normal(s->plug); + } else { + /* + * Receiving actual data on a socket means we can + * stop falling back through the candidate + * addresses to connect to. + */ + if (s->addr) { + sk_addr_free(s->addr); + s->addr = NULL; + } + plug_receive(s->plug, atmark ? 0 : 1, buf, ret); + } + break; + case SELECT_W: /* writable */ + if (!s->connected) { + /* + * select/poll reports a socket as _writable_ when an + * asynchronous connect() attempt either completes or + * fails. So first we must find out which. + */ + { + int err; + socklen_t errlen = sizeof(err); + char *errmsg = NULL; + if (getsockopt(s->s, SOL_SOCKET, SO_ERROR, &err, &errlen)<0) { + errmsg = dupprintf("getsockopt(SO_ERROR): %s", + strerror(errno)); + err = errno; /* got to put something in here */ + } else if (err != 0) { + errmsg = dupstr(strerror(err)); + } + if (errmsg) { + /* + * The asynchronous connection attempt failed. + * Report the problem via plug_log, and try again + * with the next candidate address, if we have + * more than one. + */ + SockAddr thisaddr; + assert(s->addr); + + thisaddr = sk_extractaddr_tmp(s->addr, &s->step); + plug_log(s->plug, PLUGLOG_CONNECT_FAILED, + &thisaddr, s->port, errmsg, err); + + while (err && s->addr && sk_nextaddr(s->addr, &s->step)) { + err = try_connect(s); + } + if (err) { + plug_closing_errno(s->plug, err); + return; /* socket is now presumably defunct */ + } + if (!s->connected) + return; /* another async attempt in progress */ + } else { + /* + * The connection attempt succeeded. + */ + SockAddr thisaddr = sk_extractaddr_tmp(s->addr, &s->step); + plug_log(s->plug, PLUGLOG_CONNECT_SUCCESS, + &thisaddr, s->port, NULL, 0); + } + } + + /* + * If we get here, we've managed to make a connection. + */ + if (s->addr) { + sk_addr_free(s->addr); + s->addr = NULL; + } + s->connected = true; + s->writable = true; + uxsel_tell(s); + } else { + size_t bufsize_before, bufsize_after; + s->writable = true; + bufsize_before = s->sending_oob + bufchain_size(&s->output_data); + try_send(s); + bufsize_after = s->sending_oob + bufchain_size(&s->output_data); + if (bufsize_after < bufsize_before) + plug_sent(s->plug, bufsize_after); + } + break; + } +} + +/* + * Special error values are returned from sk_namelookup and sk_new + * if there's a problem. These functions extract an error message, + * or return NULL if there's no problem. + */ +const char *sk_addr_error(SockAddr *addr) +{ + return addr->error; +} +static const char *sk_net_socket_error(Socket *sock) +{ + NetSocket *s = container_of(sock, NetSocket, sock); + return s->error; +} + +static void sk_net_set_frozen(Socket *sock, bool is_frozen) +{ + NetSocket *s = container_of(sock, NetSocket, sock); + if (s->frozen == is_frozen) + return; + s->frozen = is_frozen; + uxsel_tell(s); +} + +static SocketPeerInfo *sk_net_peer_info(Socket *sock) +{ + NetSocket *s = container_of(sock, NetSocket, sock); + union sockaddr_union addr; + socklen_t addrlen = sizeof(addr); +#ifndef NO_IPV6 + char buf[INET6_ADDRSTRLEN]; +#endif + SocketPeerInfo *pi; + + if (getpeername(s->s, &addr.sa, &addrlen) < 0) + return NULL; + + pi = snew(SocketPeerInfo); + pi->addressfamily = ADDRTYPE_UNSPEC; + pi->addr_text = NULL; + pi->port = -1; + pi->log_text = NULL; + + if (addr.storage.ss_family == AF_INET) { + pi->addressfamily = ADDRTYPE_IPV4; + memcpy(pi->addr_bin.ipv4, &addr.sin.sin_addr, 4); + pi->port = ntohs(addr.sin.sin_port); + pi->addr_text = dupstr(inet_ntoa(addr.sin.sin_addr)); + pi->log_text = dupprintf("%s:%d", pi->addr_text, pi->port); + +#ifndef NO_IPV6 + } else if (addr.storage.ss_family == AF_INET6) { + pi->addressfamily = ADDRTYPE_IPV6; + memcpy(pi->addr_bin.ipv6, &addr.sin6.sin6_addr, 16); + pi->port = ntohs(addr.sin6.sin6_port); + pi->addr_text = dupstr( + inet_ntop(AF_INET6, &addr.sin6.sin6_addr, buf, sizeof(buf))); + pi->log_text = dupprintf("[%s]:%d", pi->addr_text, pi->port); +#endif + + } else if (addr.storage.ss_family == AF_UNIX) { + pi->addressfamily = ADDRTYPE_LOCAL; + + /* + * For Unix sockets, the source address is unlikely to be + * helpful, so we leave addr_txt NULL (and we certainly can't + * fill in port, obviously). Instead, we try SO_PEERCRED and + * try to get the source pid, and put that in the log text. + */ + int pid, uid, gid; + if (so_peercred(s->s, &pid, &uid, &gid)) { + char uidbuf[64], gidbuf[64]; + sprintf(uidbuf, "%d", uid); + sprintf(gidbuf, "%d", gid); + struct passwd *pw = getpwuid(uid); + struct group *gr = getgrgid(gid); + pi->log_text = dupprintf("pid %d (%s:%s)", pid, + pw ? pw->pw_name : uidbuf, + gr ? gr->gr_name : gidbuf); + } + } else { + sfree(pi); + return NULL; + } + + return pi; +} + +int sk_net_get_fd(Socket *sock) +{ + /* This function is not fully general: it only works on NetSocket */ + if (sock->vt != &NetSocket_sockvt) + return -1; /* failure */ + NetSocket *s = container_of(sock, NetSocket, sock); + return s->s; +} + +static void uxsel_tell(NetSocket *s) +{ + int rwx = 0; + if (!s->pending_error) { + if (s->listener) { + rwx |= SELECT_R; /* read == accept */ + } else { + if (!s->connected) + rwx |= SELECT_W; /* write == connect */ + if (s->connected && !s->frozen && !s->incomingeof) + rwx |= SELECT_R | SELECT_X; + if (bufchain_size(&s->output_data)) + rwx |= SELECT_W; + } + } + uxsel_set(s->s, rwx, net_select_result); +} + +int net_service_lookup(const char *service) +{ + struct servent *se; + se = getservbyname(service, NULL); + if (se != NULL) + return ntohs(se->s_port); + else + return 0; +} + +char *get_hostname(void) +{ + size_t size = 0; + char *hostname = NULL; + do { + sgrowarray(hostname, size, size); + if ((gethostname(hostname, size) < 0) && (errno != ENAMETOOLONG)) { + sfree(hostname); + hostname = NULL; + break; + } + } while (strlen(hostname) >= size-1); + return hostname; +} + +SockAddr *platform_get_x11_unix_address(const char *sockpath, int displaynum) +{ + SockAddr *ret = snew(SockAddr); + int n; + + memset(ret, 0, sizeof *ret); + ret->superfamily = UNIX; + /* + * In special circumstances (notably Mac OS X Leopard), we'll + * have been passed an explicit Unix socket path. + */ + if (sockpath) { + n = snprintf(ret->hostname, sizeof ret->hostname, + "%s", sockpath); + } else { + n = snprintf(ret->hostname, sizeof ret->hostname, + "%s%d", X11_UNIX_PATH, displaynum); + } + + if (n < 0) + ret->error = "snprintf failed"; + else if (n >= sizeof ret->hostname) + ret->error = "X11 UNIX name too long"; + +#ifndef NO_IPV6 + ret->ais = NULL; +#else + ret->addresses = NULL; + ret->naddresses = 0; +#endif + ret->refcount = 1; + return ret; +} + +SockAddr *unix_sock_addr(const char *path) +{ + SockAddr *ret = snew(SockAddr); + int n; + + memset(ret, 0, sizeof *ret); + ret->superfamily = UNIX; + n = snprintf(ret->hostname, sizeof ret->hostname, "%s", path); + + if (n < 0) + ret->error = "snprintf failed"; + else if (n >= sizeof ret->hostname || + n >= sizeof(((struct sockaddr_un *)0)->sun_path)) + ret->error = "socket pathname too long"; + +#ifndef NO_IPV6 + ret->ais = NULL; +#else + ret->addresses = NULL; + ret->naddresses = 0; +#endif + ret->refcount = 1; + return ret; +} + +Socket *new_unix_listener(SockAddr *listenaddr, Plug *plug) +{ + int s; + union sockaddr_union u; + union sockaddr_union *addr; + int addrlen; + NetSocket *ret; + int retcode; + + /* + * Create NetSocket structure. + */ + ret = snew(NetSocket); + ret->sock.vt = &NetSocket_sockvt; + ret->error = NULL; + ret->plug = plug; + bufchain_init(&ret->output_data); + ret->writable = false; /* to start with */ + ret->sending_oob = 0; + ret->frozen = false; + ret->localhost_only = true; + ret->pending_error = 0; + ret->parent = ret->child = NULL; + ret->oobpending = false; + ret->outgoingeof = EOF_NO; + ret->incomingeof = false; + ret->listener = true; + ret->addr = listenaddr; + ret->s = -1; + + assert(listenaddr->superfamily == UNIX); + + /* + * Open socket. + */ + s = socket(AF_UNIX, SOCK_STREAM, 0); + if (s < 0) { + ret->error = strerror(errno); + return &ret->sock; + } + + cloexec(s); + + ret->oobinline = false; + + memset(&u, '\0', sizeof(u)); + u.su.sun_family = AF_UNIX; +#if __GNUC__ >= 8 +# pragma GCC diagnostic push +# pragma GCC diagnostic ignored "-Wstringop-truncation" +#endif // __GNUC__ >= 8 + strncpy(u.su.sun_path, listenaddr->hostname, sizeof(u.su.sun_path)-1); +#if __GNUC__ >= 8 +# pragma GCC diagnostic pop +#endif // __GNUC__ >= 8 + addr = &u; + addrlen = sizeof(u.su); + + if (unlink(u.su.sun_path) < 0 && errno != ENOENT) { + close(s); + ret->error = strerror(errno); + return &ret->sock; + } + + retcode = bind(s, &addr->sa, addrlen); + if (retcode < 0) { + close(s); + ret->error = strerror(errno); + return &ret->sock; + } + + if (listen(s, SOMAXCONN) < 0) { + close(s); + ret->error = strerror(errno); + return &ret->sock; + } + + ret->s = s; + + uxsel_tell(ret); + add234(sktree, ret); + + return &ret->sock; +} |