diff options
Diffstat (limited to 'src/qmail-qmtpd.c')
| -rw-r--r-- | src/qmail-qmtpd.c | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/src/qmail-qmtpd.c b/src/qmail-qmtpd.c new file mode 100644 index 0000000..f2a49cb --- /dev/null +++ b/src/qmail-qmtpd.c @@ -0,0 +1,358 @@ +#include <unistd.h> +#include "stralloc.h" +#include "buffer.h" +#include "qmail.h" +#include "now.h" +#include "str.h" +#include "fmt.h" +#include "env.h" +#include "sig.h" +#include "case.h" +#include "exit.h" +#include "scan.h" +#include "rcpthosts.h" +#include "auto_qmail.h" +#include "control.h" +#include "received.h" +#include "ip.h" +#include "byte.h" + +#define PORT_QMTPS "6209" // string compare +#define QMTP_SIZE 200000000 // 23 MB transfer limit +#define QMTP_TIMEOUT 3600 // 1 hour + +/** @file qmail-qmtpd.c -- QMTP/QMTPS server + @brief requires sslserver */ + +void badproto() { _exit(100); } +void resources() { _exit(111); } + +ssize_t safewrite(int fd,char *buf,int len) +{ + int r; + r = write(fd,buf,len); + if (r <= 0) _exit(0); + return r; +} + +char outbuf[BUFSIZE_LINE]; +buffer bo = BUFFER_INIT(safewrite,1,outbuf,sizeof(outbuf)); + +ssize_t saferead(int fd,char *buf,int len) +{ + int r; + buffer_flush(&bo); + r = read(fd,buf,len); + if (r <= 0) _exit(0); + return r; +} + +char inbuf[BUFSIZE_MESS]; // at least 2*outbuf +buffer bi = BUFFER_INIT(saferead,0,inbuf,sizeof(inbuf)); + +unsigned long getlen() +{ + unsigned long len = 0; + char ch; + for (;;) { + buffer_get(&bi,&ch,1); + if (ch == ':') return len; + if (ch < '0' || ch > '9') resources(); + if (len > QMTP_SIZE) resources(); + len = 10 * len + (ch - '0'); + } +} + +void getcomma() +{ + char ch; + buffer_get(&bi,&ch,1); + if (ch != ',') badproto(); +} + +unsigned int databytes = 0; +unsigned int bytestooverflow = 0; +struct qmail qq; + +char buf[BUFSIZE_LINE]; // sender/recipient buffer +char bufd[BUFSIZE_MESS]; // temporary data buffer +char buf2[BUFFER_SMALL]; // QMTP message buffer + +char *remotehost; +char *remoteinfo; +char *remoteip; +char *localport; +char *local; + +stralloc failure = {0}; +stralloc protocol = {0}; +stralloc tlsinfo = {0}; + +char *relayclient; +int relayclientlen = 0; + +char *ucspitls; +char *tlsversion; +char *cipher; +char *cipherperm; +char *cipherused; +char *clientdn; +char *clientcn; +char *dnemail; + +int seentls = 0; + +int modssl_info() +{ + tlsversion = env_get("SSL_PROTOCOL"); + if (!tlsversion) return 0; + seentls = 1; + + cipher = env_get("SSL_CIPHER"); + if (!cipher) cipher = "unknown"; + cipherperm = env_get("SSL_CIPHER_ALGKEYSIZE"); + if (!cipherperm) cipherperm = "unknown"; + cipherused = env_get("SSL_CIPHER_USEKEYSIZE"); + if (!cipherused) cipherused = "unknown"; + clientdn = env_get("SSL_CLIENT_S_DN"); + if (clientdn) seentls = 2; + else + clientdn = "none"; + + if (!stralloc_copys(&tlsinfo,tlsversion)) resources(); + if (!stralloc_cats(&tlsinfo,": ")) resources(); + if (!stralloc_cats(&tlsinfo,cipher)) resources(); + if (!stralloc_cats(&tlsinfo," [")) resources(); + if (!stralloc_cats(&tlsinfo,cipherused)) resources(); + if (!stralloc_cats(&tlsinfo,"/")) resources(); + if (!stralloc_cats(&tlsinfo,cipherperm)) resources(); + if (!stralloc_cats(&tlsinfo,"] \n")) resources(); + if (!stralloc_cats(&tlsinfo," DN=")) resources(); + if (!stralloc_cats(&tlsinfo,clientdn)) resources(); + if (!stralloc_0(&tlsinfo)) resources(); + + if (!stralloc_append(&protocol,"S")) resources(); + + if (seentls == 2) { + clientcn = env_get("SSL_CLIENT_S_DN_CN"); + remoteinfo = clientcn ? clientcn : clientdn; + dnemail = env_get("SSL_CLIENT_S_DN_Email"); + if (!dnemail) dnemail = "unknown"; + if (!stralloc_append(&protocol,"A")) resources(); + relayclient = ""; + } + return 1; +} + +int main() +{ + char ch; + int i; + unsigned long biglen; + unsigned long dlen; + unsigned long len; + int flagdos; + int flagsenderok; + int flagbother; + unsigned long qp; + char *result; + char *x; + unsigned long u; + + sig_pipeignore(); + sig_alarmcatch(resources); + alarm(QMTP_TIMEOUT); + + if (chdir(auto_qmail) == -1) resources(); + + if (control_init() == -1) resources(); + if (rcpthosts_init() == -1) resources(); + + if (control_readint(&databytes,"control/databytes") == -1) resources(); + x = env_get("DATABYTES"); + if (x) { scan_ulong(x,&u); databytes = u; } + if (!(databytes + 1)) --databytes; + + relayclient = env_get("RELAYCLIENT"); + remotehost = env_get("TCP6REMOTEHOST"); + if (!remotehost) remotehost = env_get("TCPREMOTEHOST"); + if (!remotehost) remotehost = "unknown"; + remoteinfo = env_get("TCP6REMOTEINFO"); + if (!remoteinfo) remoteinfo = env_get("TCPREMOTEINFO"); + remoteip = env_get("TCP6REMOTEIP"); + if (!remoteip) remoteip = env_get("TCPREMOTEIP"); + if (remoteip && byte_equal(remoteip,7,V4MAPPREFIX)) remoteip = remoteip + 7; + if (!remoteip) remoteip = "unknown"; + local = env_get("TCP6LOCALHOST"); + if (!local) local = env_get("TCPLOCALHOST"); + if (!local) local = env_get("TCP6LOCALIP"); + if (!local) local = env_get("TCPLOCALIP"); + if (!local) local = "unknown"; + localport = env_get("TCP6LOCALPORT"); + if (!localport) localport = env_get("TCPLOCALPORT"); + if (!localport) localport = "0"; + + if (!stralloc_copys(&protocol,"QMTP")) resources(); + if (!case_diffs(localport,PORT_QMTPS)) + if (!modssl_info()) resources(); + + if (relayclient) + relayclientlen = str_len(relayclient); + + for (;;) { // https://cr.yp.to/proto/qmtp.txt + if (!stralloc_copys(&failure,"")) resources(); + flagsenderok = 1; + + len = getlen(); // package to read + if (len == 0) badproto(); + + if (databytes) bytestooverflow = databytes + 1; + if (qmail_open(&qq) == -1) resources(); + qp = qmail_qp(&qq); + + buffer_get(&bi,&ch,1); + --len; + if (ch == 10) flagdos = 0; + else if (ch == 13) flagdos = 1; + else badproto(); + + /* no fakehelo, no spfinfo */ + + received(&qq,protocol.s,local,remoteip,remotehost,remoteinfo,(char *) 0,tlsinfo.s,(char *) 0); + + /* XXX: check for loops? only if len is big? - message */ + + if (flagdos) + while (len > 0) { + buffer_get(&bi,&ch,1); + --len; + while ((ch == 13) && len) { + buffer_get(&bi,&ch,1); + --len; + if (ch == 10) break; + if (bytestooverflow) if (!--bytestooverflow) qmail_fail(&qq); + qmail_put(&qq,"\015",1); + } + if (bytestooverflow) if (!--bytestooverflow) qmail_fail(&qq); + qmail_put(&qq,&ch,1); + } + else { + if (databytes) + if (len > databytes) { + bytestooverflow = 0; + qmail_fail(&qq); + } + while (len > 0) { /* XXX: DJB: could speed this up, obviously; FEH: done */ + dlen = (len < BUFSIZE_LINE) ? len : BUFSIZE_LINE; + buffer_get(&bi,bufd,dlen); + qmail_put(&qq,bufd,dlen); + len -= dlen; + } + } + getcomma(); + + len = getlen(); // QMTP sender + + if (len >= BUFSIZE_LINE) { + buf[0] = 0; + flagsenderok = 0; + for (i = 0; i < len; ++i) + buffer_get(&bi,&ch,1); + } + else { + for (i = 0; i < len; ++i) { + buffer_get(&bi,buf + i,1); + if (!buf[i]) flagsenderok = 0; + } + buf[len] = 0; + } + getcomma(); + + flagbother = 0; + qmail_from(&qq,buf); + if (!flagsenderok) qmail_fail(&qq); + + biglen = getlen(); // QMTP recipients + while (biglen > 0) { + if (!stralloc_append(&failure,"")) resources(); + + len = 0; + for (;;) { + if (!biglen) badproto(); + buffer_get(&bi,&ch,1); + --biglen; + if (ch == ':') break; + if (ch < '0' || ch > '9') resources(); + if (len > QMTP_SIZE) resources(); + len = 10 * len + (ch - '0'); + } + if (len >= biglen) badproto(); + if (len + relayclientlen >= BUFSIZE_LINE) { + failure.s[failure.len - 1] = 'L'; + for (i = 0; i < len; ++i) + buffer_get(&bi,&ch,1); + } + else { + for (i = 0; i < len; ++i) { + buffer_get(&bi,buf + i,1); + if (!buf[i]) failure.s[failure.len - 1] = 'N'; + } + buf[len] = 0; + + if (relayclientlen) + str_copy(buf + len,relayclient); + if (!relayclient) + switch (rcpthosts(buf,len)) { + case -1: resources(); + case 0: failure.s[failure.len - 1] = 'D'; + } + + if (!failure.s[failure.len - 1]) { + qmail_to(&qq,buf); + flagbother = 1; + } + } + getcomma(); + biglen -= (len + 1); + } + getcomma(); + + if (!flagbother) qmail_fail(&qq); + result = qmail_close(&qq); + if (!flagsenderok) result = "D Unacceptable sender (#5.1.7)"; + if (databytes) if (!bytestooverflow) result = "D Sorry, that message size exceeds my databytes limit (#5.3.4)"; + + if (*result) + len = str_len(result); + else { + /* success! */ + len = 0; + len += fmt_str(buf2 + len,"K Ok "); + len += fmt_ulong(buf2 + len,(unsigned long) now()); + len += fmt_str(buf2 + len," qp "); + len += fmt_ulong(buf2 + len,qp); + buf2[len] = 0; + result = buf2; + } + + len = fmt_ulong(buf,len); + buf[len++] = ':'; + len += fmt_str(buf + len,result); + buf[len++] = ','; + + for (i = 0; i < failure.len; ++i) + switch (failure.s[i]) { + case 0: + buffer_put(&bo,buf,len); + break; + case 'D': + buffer_puts(&bo,"66:D Sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1),"); + break; + default: + buffer_puts(&bo,"46:D Sorry, I can't handle that recipient (#5.1.3),"); + break; + } + + /* bo will be flushed when we read from the network again */ + } +} |