X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=secnet.git;a=blobdiff_plain;f=udp.c;h=1535f290c587a9efaa261d1ad2da740283ad024e;hp=8f0bb8bde3fdeb33b46c2f7bb2b3cd46d6c4505e;hb=2d80199d7bc25b4c6e4a5ac986f8902770e82d96;hpb=53f4e66603bcc2d21c70ad7a69db5fda6da5d645 diff --git a/udp.c b/udp.c index 8f0bb8b..1535f29 100644 --- a/udp.c +++ b/udp.c @@ -1,5 +1,24 @@ /* UDP send/receive module for secnet */ +/* + * This file is part of secnet. + * See README for full list of copyright holders. + * + * secnet is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version d of the License, or + * (at your option) any later version. + * + * secnet is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * version 3 along with secnet; if not, see + * https://www.gnu.org/licenses/gpl.html. + */ + /* This module enables sites to communicate by sending UDP * packets. When an instance of the module is created we can * optionally bind to a particular local IP address (not implemented @@ -30,6 +49,8 @@ static comm_sendmsg_fn udp_sendmsg; struct udp { struct udpcommon uc; struct udpsocks socks; + bool_t addr_configured; + unsigned counter; }; /* @@ -52,9 +73,10 @@ static const char *udp_addr_to_string(void *commst, const struct comm_addr *ca) int ix=ca->ix>=0 ? ca->ix : 0; assert(ix>=0 && ixn_socks); - snprintf(sbuf, sizeof(sbuf), "udp:%s%s-%s", + snprintf(sbuf, sizeof(sbuf), "udp#%u@l%d:%s%s-%s", + st->counter, st->uc.cc.loc.line, iaddr_to_string(&socks->socks[ix].addr), - ca->ix<0 ? "&" : "", + ca->ix<0 && socks->n_socks>1 ? "&" : "", iaddr_to_string(&ca->ia)); return sbuf; } @@ -72,6 +94,37 @@ static int udp_socks_beforepoll(void *state, struct pollfd *fds, int *nfds_io, return 0; } +const char *af_name(int af) +{ + switch (af) { + case AF_INET6: return "IPv6"; + case AF_INET: return "IPv4"; + case 0: return "(any)"; + default: abort(); + } +} + +void udp_sock_experienced(struct log_if *lg, struct udpcommon *uc, + struct udpsocks *socks, struct udpsock *us, + const union iaddr *dest, int af, + int r, int errnoval) +{ + bool_t success=r>=0; + if (us->experienced[!!dest][af][success]++) + return; + lg_perror(lg, uc->cc.cl.description, &uc->cc.loc, + success ? M_INFO : M_WARNING, + success ? 0 : errnoval, + "%s %s experiencing some %s %s%s%s%s%s%s", + socks->desc,iaddr_to_string(&us->addr), + success?"success":"trouble", + dest?"transmitting":"receiving", + af?" ":"", af?af_name(af):"", + dest?" (to ":"", + dest?iaddr_to_string(dest):"", + dest?")":""); +} + static void udp_socks_afterpoll(void *state, struct pollfd *fds, int nfds) { struct udpsocks *socks=state; @@ -85,10 +138,11 @@ static void udp_socks_afterpoll(void *state, struct pollfd *fds, int nfds) struct commcommon *cc=&uc->cc; for (i=0; in_socks; i++) { + struct udpsock *us=&socks->socks[i]; if (i>=nfds) continue; if (!(fds[i].revents & POLLIN)) continue; - assert(fds[i].fd == socks->socks[i].fd); - int fd=socks->socks[i].fd; + assert(fds[i].fd == us->fd); + int fd=us->fd; do { fromlen=sizeof(from); BUF_ASSERT_FREE(cc->rbuf); @@ -103,7 +157,7 @@ static void udp_socks_afterpoll(void *state, struct pollfd *fds, int nfds) /* Check that the packet came from our poxy server; we shouldn't be contacted directly by anybody else (since they can trivially forge source addresses) */ - if (!iaddr_equal(&from,&uc->proxy)) { + if (!iaddr_equal(&from,&uc->proxy,False)) { Message(M_INFO,"udp: received packet that's not " "from the proxy\n"); BUF_FREE(cc->rbuf); @@ -120,7 +174,10 @@ static void udp_socks_afterpoll(void *state, struct pollfd *fds, int nfds) ca.ia=from; ca.ix=i; done=comm_notify(&cc->notify, cc->rbuf, &ca); - if (!done) { + if (done) { + udp_sock_experienced(0,uc,socks,us,0, + from.sa.sa_family,0,0); + } else { uint32_t msgtype; if (cc->rbuf->size>12 /* prevents traffic amplification */ && ((msgtype=get_uint32(cc->rbuf->start+8)) @@ -134,7 +191,9 @@ static void udp_socks_afterpoll(void *state, struct pollfd *fds, int nfds) BUF_FREE(cc->rbuf); } BUF_ASSERT_FREE(cc->rbuf); - } else { + } else { /* rv<=0 */ + if (errno!=EINTR && !iswouldblock(errno)) + udp_sock_experienced(0,uc,socks,us, 0,0, rv,errno); BUF_FREE(cc->rbuf); } } while (rv>=0); @@ -142,7 +201,8 @@ static void udp_socks_afterpoll(void *state, struct pollfd *fds, int nfds) } static bool_t udp_sendmsg(void *commst, struct buffer_if *buf, - const struct comm_addr *dest) + const struct comm_addr *dest, + struct comm_clientinfo *clientinfo) { struct udp *st=commst; struct udpcommon *uc=&st->uc; @@ -150,6 +210,7 @@ static bool_t udp_sendmsg(void *commst, struct buffer_if *buf, uint8_t *sa; if (uc->use_proxy) { + struct udpsock *us=&socks->socks[0]; sa=buf_prepend(buf,8); if (dest->ia.sa.sa_family != AF_INET) { Message(M_INFO, @@ -160,18 +221,22 @@ static bool_t udp_sendmsg(void *commst, struct buffer_if *buf, memcpy(sa,&dest->ia.sin.sin_addr,4); memset(sa+4,0,4); memcpy(sa+6,&dest->ia.sin.sin_port,2); - sendto(socks->socks[0].fd,sa,buf->size+8,0,&uc->proxy.sa, + int r=sendto(us->fd,sa,buf->size+8,0,&uc->proxy.sa, iaddr_socklen(&uc->proxy)); + udp_sock_experienced(0,uc,socks,us, &dest->ia,0, r,errno); buf_unprepend(buf,8); } else { int i,r; bool_t allunsupported=True; + int af=dest->ia.sa.sa_family; for (i=0; in_socks; i++) { - if (dest->ia.sa.sa_family != socks->socks[i].addr.sa.sa_family) + struct udpsock *us=&socks->socks[i]; + if (us->addr.sa.sa_family != af) /* no point even trying */ continue; - r=sendto(socks->socks[i].fd, buf->start, buf->size, 0, + r=sendto(us->fd, buf->start, buf->size, 0, &dest->ia.sa, iaddr_socklen(&dest->ia)); + udp_sock_experienced(0,uc,socks,us, &dest->ia,af, r,errno); if (r>=0) return True; if (!(errno==EAFNOSUPPORT || errno==ENETUNREACH)) /* who knows what that error means? */ @@ -183,12 +248,13 @@ static bool_t udp_sendmsg(void *commst, struct buffer_if *buf, return True; } -bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us, - int failmsgclass) +void udp_destroy_socket(struct udpcommon *uc, struct udpsock *us) { - const union iaddr *addr=&us->addr; - struct commcommon *cc=&uc->cc; - us->fd=-1; + if (us->fd>=0) { + close(us->fd); + us->fd=-1; + } +} #define FAIL_LG 0, cc->cl.description, &cc->loc, failmsgclass #define FAIL(...) do{ \ @@ -196,10 +262,39 @@ bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us, goto failed; \ }while(0) +static bool_t record_socket_gotaddr(struct udpcommon *uc, struct udpsock *us, + int failmsgclass) +{ + struct commcommon *cc=&uc->cc; + socklen_t salen=sizeof(us->addr); + int r=getsockname(us->fd,&us->addr.sa,&salen); + if (r) FAIL("getsockname()"); + if (salen>sizeof(us->addr)) { errno=0; FAIL("getsockname() length"); } + return True; + + failed: + return False; +} + +bool_t udp_import_socket(struct udpcommon *uc, struct udpsock *us, + int failmsgclass, int fd) +{ + FILLZERO(us->experienced); + us->fd=fd; + return record_socket_gotaddr(uc,us,failmsgclass); +} + +bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us, + int failmsgclass) +{ + const union iaddr *addr=&us->addr; + struct commcommon *cc=&uc->cc; + us->fd=-1; + + FILLZERO(us->experienced); us->fd=socket(addr->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP); if (us->fd<0) FAIL("socket"); - if (fcntl(us->fd, F_SETFL, fcntl(us->fd, F_GETFL)|O_NONBLOCK)==-1) - FAIL("fcntl(set O_NONBLOCK)"); + setnonblock(us->fd); setcloexec(us->fd); #ifdef CONFIG_IPV6 if (addr->sa.sa_family==AF_INET6) { @@ -214,6 +309,9 @@ bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us, if (uc->authbind) { pid_t c; int status; + char desc[200]; + snprintf(desc,sizeof(desc),"authbind for %s: %s", + iaddr_to_string(addr), uc->authbind); /* XXX this fork() and waitpid() business needs to be hidden in some system-specific library functions. */ @@ -224,6 +322,7 @@ bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us, char *argv[5], addrstr[33], portstr[5]; const char *addrfam; int port; + afterfork(); switch (addr->sa.sa_family) { case AF_INET: sprintf(addrstr,"%08lX",(long)addr->sin.sin_addr.s_addr); @@ -258,37 +357,60 @@ bool_t udp_make_socket(struct udpcommon *uc, struct udpsock *us, if (errno==EINTR) continue; FAIL("waitpid for authbind"); } - if (WIFSIGNALED(status)) { - lg_perror(FAIL_LG,0,"authbind died on signal %s (%d)", - strsignal(WTERMSIG(status)),WTERMSIG(status)); - goto failed; - } - if (WIFEXITED(status) && WEXITSTATUS(status)!=0) { - lg_perror(FAIL_LG,0, - "authbind died with error exit status %d", - WEXITSTATUS(status)); + if (status) { + if (WIFEXITED(status) && WEXITSTATUS(status)<127) { + int es=WEXITSTATUS(status); + lg_perror(FAIL_LG,es, + "%s exited with error exit status %d;" + " indicates error",desc,es); + } else { + lg_exitstatus(FAIL_LG,status,desc); + } goto failed; } } else { if (bind(us->fd, &addr->sa, iaddr_socklen(addr))!=0) FAIL("bind (%s)",iaddr_to_string(addr)); } + + bool_t ok=record_socket_gotaddr(uc,us,failmsgclass); + if (!ok) goto failed; + return True; failed: - if (us->fd>=0) { - close(us->fd); - us->fd=-1; - } + udp_destroy_socket(uc,us); return False; +} #undef FAIL + +void udp_socks_register(struct udpcommon *uc, struct udpsocks *socks, + const char *desc) +{ + socks->uc=uc; + socks->desc=desc; + socks->interest= + register_for_poll(socks,udp_socks_beforepoll,udp_socks_afterpoll,"udp"); } -void udp_socks_register(struct udpcommon *uc, struct udpsocks *socks) +void udp_socks_deregister(struct udpcommon *uc, struct udpsocks *socks) { socks->uc=uc; - register_for_poll(socks,udp_socks_beforepoll,udp_socks_afterpoll,"udp"); + deregister_for_poll(socks->interest); +} + +void udp_socks_childpersist(struct udpcommon *uc, struct udpsocks *socks) +{ + int i; + for (i=0; in_socks; i++) + udp_destroy_socket(uc,&socks->socks[i]); +} + +static void udp_childpersist_hook(void *sst, uint32_t new_phase) +{ + struct udp *st=sst; + udp_socks_childpersist(&st->uc,&st->socks); } static void udp_phase_hook(void *sst, uint32_t new_phase) @@ -297,15 +419,25 @@ static void udp_phase_hook(void *sst, uint32_t new_phase) struct udpsocks *socks=&st->socks; struct udpcommon *uc=&st->uc; int i; - for (i=0; in_socks; i++) - udp_make_socket(uc,&socks->socks[i],M_FATAL); + bool_t anydone=0; + + for (i=0; in_socks; i++) { + bool_t required=st->addr_configured + || (!anydone && i==socks->n_socks-1); + anydone += udp_make_socket(uc,&socks->socks[i], + required ? M_FATAL : M_WARNING); + } + + udp_socks_register(uc,socks, uc->use_proxy ? "proxy" : "socket"); - udp_socks_register(uc,socks); + add_hook(PHASE_CHILDPERSIST,udp_childpersist_hook,st); } static list_t *udp_apply(closure_t *self, struct cloc loc, dict_t *context, list_t *args) { + static unsigned counter; + struct udp *st; list_t *caddrl; list_t *l; @@ -320,6 +452,8 @@ static list_t *udp_apply(closure_t *self, struct cloc loc, dict_t *context, struct udpsocks *socks=&st->socks; struct commcommon *cc=&uc->cc; + st->counter=counter++; + union iaddr defaultaddrs[] = { #ifdef CONFIG_IPV6 { .sin6 = { .sin6_family=AF_INET6, @@ -332,14 +466,16 @@ static list_t *udp_apply(closure_t *self, struct cloc loc, dict_t *context, }; caddrl=dict_lookup(d,"address"); - socks->n_socks=caddrl ? list_length(caddrl) : (int)ARRAY_SIZE(defaultaddrs); + st->addr_configured=!!caddrl; + socks->n_socks=st->addr_configured ? list_length(caddrl) + : (int)ARRAY_SIZE(defaultaddrs); if (socks->n_socks<=0 || socks->n_socks>UDP_MAX_SOCKETS) cfgfatal(cc->loc,"udp","`address' must be 1..%d addresses", UDP_MAX_SOCKETS); for (i=0; in_socks; i++) { struct udpsock *us=&socks->socks[i]; - if (!list_length(caddrl)) { + if (!st->addr_configured) { us->addr=defaultaddrs[i]; } else { string_item_to_iaddr(list_elem(caddrl,i),uc->port,&us->addr,"udp");