diff options
Diffstat (limited to 'ucspi-tcp-0.88/tcpserver.c')
| -rw-r--r-- | ucspi-tcp-0.88/tcpserver.c | 426 |
1 files changed, 426 insertions, 0 deletions
diff --git a/ucspi-tcp-0.88/tcpserver.c b/ucspi-tcp-0.88/tcpserver.c new file mode 100644 index 0000000..979a0be --- /dev/null +++ b/ucspi-tcp-0.88/tcpserver.c @@ -0,0 +1,426 @@ +#include <sys/types.h> +#include <sys/param.h> +#include <netdb.h> +#include "uint16.h" +#include "str.h" +#include "byte.h" +#include "fmt.h" +#include "scan.h" +#include "ip4.h" +#include "fd.h" +#include "exit.h" +#include "env.h" +#include "prot.h" +#include "open.h" +#include "wait.h" +#include "readwrite.h" +#include "stralloc.h" +#include "alloc.h" +#include "buffer.h" +#include "error.h" +#include "strerr.h" +#include "sgetopt.h" +#include "pathexec.h" +#include "socket.h" +#include "ndelay.h" +#include "remoteinfo.h" +#include "rules.h" +#include "sig.h" +#include "dns.h" + +int verbosity = 1; +int flagkillopts = 1; +int flagdelay = 1; +char *banner = ""; +int flagremoteinfo = 1; +int flagremotehost = 1; +int flagparanoid = 0; +unsigned long timeout = 26; + +static stralloc tcpremoteinfo; + +uint16 localport; +char localportstr[FMT_ULONG]; +char localip[4]; +char localipstr[IP4_FMT]; +static stralloc localhostsa; +char *localhost = 0; + +uint16 remoteport; +char remoteportstr[FMT_ULONG]; +char remoteip[4]; +char remoteipstr[IP4_FMT]; +static stralloc remotehostsa; +char *remotehost = 0; + +char strnum[FMT_ULONG]; +char strnum2[FMT_ULONG]; + +static stralloc tmp; +static stralloc fqdn; +static stralloc addresses; + +char bspace[16]; +buffer b; + + + +/* ---------------------------- child */ + +#define DROP "tcpserver: warning: dropping connection, " + +int flagdeny = 0; +int flagallownorules = 0; +char *fnrules = 0; + +void drop_nomem(void) +{ + strerr_die2sys(111,DROP,"out of memory"); +} +void cats(char *s) +{ + if (!stralloc_cats(&tmp,s)) drop_nomem(); +} +void append(char *ch) +{ + if (!stralloc_append(&tmp,ch)) drop_nomem(); +} +void safecats(char *s) +{ + char ch; + int i; + + for (i = 0;i < 100;++i) { + ch = s[i]; + if (!ch) return; + if (ch < 33) ch = '?'; + if (ch > 126) ch = '?'; + if (ch == '%') ch = '?'; /* logger stupidity */ + if (ch == ':') ch = '?'; + append(&ch); + } + cats("..."); +} +void env(char *s,char *t) +{ + if (!pathexec_env(s,t)) drop_nomem(); +} +void drop_rules(void) +{ + strerr_die4sys(111,DROP,"unable to read ",fnrules,": "); +} + +void found(char *data,unsigned int datalen) +{ + unsigned int next0; + unsigned int split; + + while ((next0 = byte_chr(data,datalen,0)) < datalen) { + switch(data[0]) { + case 'D': + flagdeny = 1; + break; + case '+': + split = str_chr(data + 1,'='); + if (data[1 + split] == '=') { + data[1 + split] = 0; + env(data + 1,data + 1 + split + 1); + } + break; + } + ++next0; + data += next0; datalen -= next0; + } +} + +void doit(int t) +{ + int j; + + remoteipstr[ip4_fmt(remoteipstr,remoteip)] = 0; + + if (verbosity >= 2) { + strnum[fmt_ulong(strnum,getpid())] = 0; + strerr_warn4("tcpserver: pid ",strnum," from ",remoteipstr,0); + } + + if (flagkillopts) + socket_ipoptionskill(t); + if (!flagdelay) + socket_tcpnodelay(t); + + if (*banner) { + buffer_init(&b,write,t,bspace,sizeof bspace); + if (buffer_putsflush(&b,banner) == -1) + strerr_die2sys(111,DROP,"unable to print banner: "); + } + + if (socket_local4(t,localip,&localport) == -1) + strerr_die2sys(111,DROP,"unable to get local address: "); + + localipstr[ip4_fmt(localipstr,localip)] = 0; + remoteportstr[fmt_ulong(remoteportstr,remoteport)] = 0; + + if (!localhost) + if (dns_name4(&localhostsa,localip) == 0) + if (localhostsa.len) { + if (!stralloc_0(&localhostsa)) drop_nomem(); + localhost = localhostsa.s; + } + env("PROTO","TCP"); + env("TCPLOCALIP",localipstr); + env("TCPLOCALPORT",localportstr); + env("TCPLOCALHOST",localhost); + + if (flagremotehost) + if (dns_name4(&remotehostsa,remoteip) == 0) + if (remotehostsa.len) { + if (flagparanoid) + if (dns_ip4(&tmp,&remotehostsa) == 0) + for (j = 0;j + 4 <= tmp.len;j += 4) + if (byte_equal(remoteip,4,tmp.s + j)) { + flagparanoid = 0; + break; + } + if (!flagparanoid) { + if (!stralloc_0(&remotehostsa)) drop_nomem(); + remotehost = remotehostsa.s; + } + } + env("TCPREMOTEIP",remoteipstr); + env("TCPREMOTEPORT",remoteportstr); + env("TCPREMOTEHOST",remotehost); + + if (flagremoteinfo) { + if (remoteinfo(&tcpremoteinfo,remoteip,remoteport,localip,localport,timeout) == -1) + flagremoteinfo = 0; + if (!stralloc_0(&tcpremoteinfo)) drop_nomem(); + } + env("TCPREMOTEINFO",flagremoteinfo ? tcpremoteinfo.s : 0); + + if (fnrules) { + int fdrules; + fdrules = open_read(fnrules); + if (fdrules == -1) { + if (errno != error_noent) drop_rules(); + if (!flagallownorules) drop_rules(); + } + else { + if (rules(found,fdrules,remoteipstr,remotehost,flagremoteinfo ? tcpremoteinfo.s : 0) == -1) drop_rules(); + close(fdrules); + } + } + + if (verbosity >= 2) { + strnum[fmt_ulong(strnum,getpid())] = 0; + if (!stralloc_copys(&tmp,"tcpserver: ")) drop_nomem(); + safecats(flagdeny ? "deny" : "ok"); + cats(" "); safecats(strnum); + cats(" "); if (localhost) safecats(localhost); + cats(":"); safecats(localipstr); + cats(":"); safecats(localportstr); + cats(" "); if (remotehost) safecats(remotehost); + cats(":"); safecats(remoteipstr); + cats(":"); if (flagremoteinfo) safecats(tcpremoteinfo.s); + cats(":"); safecats(remoteportstr); + cats("\n"); + buffer_putflush(buffer_2,tmp.s,tmp.len); + } + + if (flagdeny) _exit(100); +} + + + +/* ---------------------------- parent */ + +#define FATAL "tcpserver: fatal: " + +void usage(void) +{ + strerr_warn1("\ +tcpserver: usage: tcpserver \ +[ -1UXpPhHrRoOdDqQv ] \ +[ -c limit ] \ +[ -x rules.cdb ] \ +[ -B banner ] \ +[ -g gid ] \ +[ -u uid ] \ +[ -b backlog ] \ +[ -l localname ] \ +[ -t timeout ] \ +host port program",0); + _exit(100); +} + +unsigned long limit = 40; +unsigned long numchildren = 0; + +int flag1 = 0; +unsigned long backlog = 20; +unsigned long uid = 0; +unsigned long gid = 0; + +void printstatus(void) +{ + if (verbosity < 2) return; + strnum[fmt_ulong(strnum,numchildren)] = 0; + strnum2[fmt_ulong(strnum2,limit)] = 0; + strerr_warn4("tcpserver: status: ",strnum,"/",strnum2,0); +} + +void sigterm() +{ + _exit(0); +} + +void sigchld() +{ + int wstat; + int pid; + + while ((pid = wait_nohang(&wstat)) > 0) { + if (verbosity >= 2) { + strnum[fmt_ulong(strnum,pid)] = 0; + strnum2[fmt_ulong(strnum2,wstat)] = 0; + strerr_warn4("tcpserver: end ",strnum," status ",strnum2,0); + } + if (numchildren) --numchildren; printstatus(); + } +} + +main(int argc,char **argv) +{ + char *hostname; + char *portname; + int opt; + struct servent *se; + char *x; + unsigned long u; + int s; + int t; + + while ((opt = getopt(argc,argv,"dDvqQhHrR1UXx:t:u:g:l:b:B:c:pPoO")) != opteof) + switch(opt) { + case 'b': scan_ulong(optarg,&backlog); break; + case 'c': scan_ulong(optarg,&limit); break; + case 'X': flagallownorules = 1; break; + case 'x': fnrules = optarg; break; + case 'B': banner = optarg; break; + case 'd': flagdelay = 1; break; + case 'D': flagdelay = 0; break; + case 'v': verbosity = 2; break; + case 'q': verbosity = 0; break; + case 'Q': verbosity = 1; break; + case 'P': flagparanoid = 0; break; + case 'p': flagparanoid = 1; break; + case 'O': flagkillopts = 1; break; + case 'o': flagkillopts = 0; break; + case 'H': flagremotehost = 0; break; + case 'h': flagremotehost = 1; break; + case 'R': flagremoteinfo = 0; break; + case 'r': flagremoteinfo = 1; break; + case 't': scan_ulong(optarg,&timeout); break; + case 'U': x = env_get("UID"); if (x) scan_ulong(x,&uid); + x = env_get("GID"); if (x) scan_ulong(x,&gid); break; + case 'u': scan_ulong(optarg,&uid); break; + case 'g': scan_ulong(optarg,&gid); break; + case '1': flag1 = 1; break; + case 'l': localhost = optarg; break; + default: usage(); + } + argc -= optind; + argv += optind; + + if (!verbosity) + buffer_2->fd = -1; + + hostname = *argv++; + if (!hostname) usage(); + if (str_equal(hostname,"")) hostname = "0.0.0.0"; + if (str_equal(hostname,"0")) hostname = "0.0.0.0"; + + x = *argv++; + if (!x) usage(); + if (!x[scan_ulong(x,&u)]) + localport = u; + else { + se = getservbyname(x,"tcp"); + if (!se) + strerr_die3x(111,FATAL,"unable to figure out port number for ",x); + localport = ntohs(se->s_port); + } + + if (!*argv) usage(); + + sig_block(sig_child); + sig_catch(sig_child,sigchld); + sig_catch(sig_term,sigterm); + sig_ignore(sig_pipe); + + if (!stralloc_copys(&tmp,hostname)) + strerr_die2x(111,FATAL,"out of memory"); + if (dns_ip4_qualify(&addresses,&fqdn,&tmp) == -1) + strerr_die4sys(111,FATAL,"temporarily unable to figure out IP address for ",hostname,": "); + if (addresses.len < 4) + strerr_die3x(111,FATAL,"no IP address for ",hostname); + byte_copy(localip,4,addresses.s); + + s = socket_tcp(); + if (s == -1) + strerr_die2sys(111,FATAL,"unable to create socket: "); + if (socket_bind4_reuse(s,localip,localport) == -1) + strerr_die2sys(111,FATAL,"unable to bind: "); + if (socket_local4(s,localip,&localport) == -1) + strerr_die2sys(111,FATAL,"unable to get local address: "); + if (socket_listen(s,backlog) == -1) + strerr_die2sys(111,FATAL,"unable to listen: "); + ndelay_off(s); + + if (gid) if (prot_gid(gid) == -1) + strerr_die2sys(111,FATAL,"unable to set gid: "); + if (uid) if (prot_uid(uid) == -1) + strerr_die2sys(111,FATAL,"unable to set uid: "); + + + localportstr[fmt_ulong(localportstr,localport)] = 0; + if (flag1) { + buffer_init(&b,write,1,bspace,sizeof bspace); + buffer_puts(&b,localportstr); + buffer_puts(&b,"\n"); + buffer_flush(&b); + } + + close(0); + close(1); + printstatus(); + + for (;;) { + while (numchildren >= limit) sig_pause(); + + sig_unblock(sig_child); + t = socket_accept4(s,remoteip,&remoteport); + sig_block(sig_child); + + if (t == -1) continue; + ++numchildren; printstatus(); + + switch(fork()) { + case 0: + close(s); + doit(t); + if ((fd_move(0,t) == -1) || (fd_copy(1,0) == -1)) + strerr_die2sys(111,DROP,"unable to set up descriptors: "); + sig_uncatch(sig_child); + sig_unblock(sig_child); + sig_uncatch(sig_term); + sig_uncatch(sig_pipe); + pathexec(argv); + strerr_die4sys(111,DROP,"unable to run ",*argv,": "); + case -1: + strerr_warn2(DROP,"unable to fork: ",&strerr_sys); + --numchildren; printstatus(); + } + close(t); + } +} |