1 files changed, 301 insertions, 0 deletions
diff --git a/src/qmail-popup.c b/src/qmail-popup.c
new file mode 100644
index 0000000..522e719
--- /dev/null
+++ b/src/qmail-popup.c
@@ -0,0 +1,301 @@
+#include <unistd.h>
+#include "commands.h"
+#include "fd.h"
+#include "sig.h"
+#include "stralloc.h"
+#include "buffer.h"
+#include "alloc.h"
+#include "wait.h"
+#include "str.h"
+#include "byte.h"
+#include "now.h"
+#include "fmt.h"
+#include "case.h"
+#include "exit.h"
+#include "timeout.h"
+#include "env.h"
+#include "tls_start.h"
+#include "ip.h"
+
+#define PORT_POP3S "995"
+#define FDIN 0
+#define FDOUT 1
+#define FDAUTH 3
+#define FDLOG 5
+
+void die() { _exit(1); }
+
+ssize_t saferead(int fd,char *buf,int len)
+{
+  int r;
+  r = timeoutread(1200,fd,buf,len);
+  if (r <= 0) die();
+  return r;
+}
+
+ssize_t safewrite(int fd,char *buf,int len)
+{
+  int r;
+  r = timeoutwrite(1200,fd,buf,len);
+  if (r <= 0) die();
+  return r;
+}
+
+char outbuf[128];
+buffer bo = BUFFER_INIT(safewrite,FDOUT,outbuf,sizeof(outbuf));
+
+char inbuf[128];
+buffer bi = BUFFER_INIT(saferead,FDIN,inbuf,sizeof(inbuf));
+
+void outs(char *s)
+{
+  buffer_puts(&bo,s);
+}
+void flush()
+{
+  buffer_flush(&bo);
+}
+void err(char *s)
+{
+  outs("-ERR ");
+  outs(s);
+  outs("\r\n");
+  flush();
+}
+
+/* Logging */
+
+stralloc protocol = {0};  
+stralloc auth = {0};
+char *localport;
+char *remoteip;
+char *remotehost;
+
+char strnum[FMT_ULONG];
+char logbuf[512];
+buffer bl = BUFFER_INIT(safewrite,FDLOG,logbuf,sizeof(logbuf));
+
+void logs(char *s) { if (buffer_puts(&bl,s) == -1) _exit(1); }
+void logp(char *s) { logs(" P:"); logs(s); }
+void logh(char *s1, char *s2) { logs(" S:"); logs(s1); logs(":"); logs(s2); }  
+void logu(char *s) { logs(" ?~ '"); logs(s); logs("'"); }  
+void logn(char *s) { if (buffer_puts(&bl,s) == -1) _exit(1); if (buffer_flush(&bl) == -1) _exit(1); }
+void logpid() { strnum[fmt_ulong(strnum,getpid())] = 0; logs("qmail-popup: pid "); logs(strnum); logs(" "); }
+void log_pop(char *s1,char *s2,char *s3,char *s4,char *s5,char *s6)  
+  { logpid(); logs(s1); logs(s2); logp(s3); logh(s4,s5), logu(s6), logn("\n"); }
+
+void die_usage() { err("usage: popup hostname subprogram"); die(); }
+void die_nomem() { err("out of memory"); die(); }
+void die_pipe() { err("unable to open pipe"); die(); }
+void die_write() { err("unable to write pipe"); die(); }
+void die_fork() { err("unable to fork"); die(); }
+void die_childcrashed() { err("aack, child crashed"); }
+void die_badauth() { err("authorization failed"); }
+void die_tls() { err("TLS startup failed"); die(); }
+void die_notls() { 
+  err("TLS required but not negotiated"); 
+  log_pop("Reject::STLS::","Any","POP3",remoteip,remotehost,"unknown");
+  die(); 
+}
+
+void err_syntax() { err("syntax error"); }
+void err_wantuser() { err("USER first"); }
+void err_authoriz() { err("authorization first"); }
+
+void okay() { outs("+OK \r\n"); flush(); }
+void pop3_quit() { okay(); die(); }
+
+void poplog_init()
+{
+  if (!stralloc_copys(&protocol,"POP3")) die_nomem();
+  localport = env_get("TCP6LOCALPORT");
+  if (!localport) localport  = env_get("TCPLOCALPORT");
+  if (!localport) localport = "unknown";
+  if (!case_diffs(localport,PORT_POP3S))
+    if (!stralloc_cats(&protocol,"S")) die_nomem();
+  remoteip = env_get("TCP6REMOTEIP");
+  if (remoteip && byte_equal(remoteip,7,V4MAPPREFIX)) remoteip = remoteip + 7; 
+  if (!remoteip) remoteip  = env_get("TCPREMOTEIP");
+  if (!remoteip) remoteip = "unknown";
+  remotehost = env_get("TCP6REMOTEHOST");
+  if (!remotehost) remotehost = env_get("TCPREMOTEHOST");
+  if (!remotehost) remotehost = "unknown";
+}
+
+char unique[FMT_ULONG + FMT_ULONG + 3];
+char *hostname;
+stralloc username = {0};
+int seenuser = 0;
+char **childargs;
+buffer ba;
+char authbuf[128];
+int stls = 0;
+int seenstls = 0;
+int apop = 0;
+
+void doanddie(char *user,unsigned int userlen,char *pass) /* userlen: including 0 byte */
+{
+  int child;
+  int wstat;
+  int pi[2];
+ 
+  if (fd_copy(2,1) == -1) die_pipe(); 
+  close(FDAUTH);
+  if (pipe(pi) == -1) die_pipe();
+  if (pi[0] != FDAUTH) die_pipe();
+  switch (child = fork()) {
+    case -1:
+      die_fork();
+    case 0:
+      close(pi[1]);
+      sig_pipedefault();
+      execvp(*childargs,childargs);
+      _exit(1);
+  }
+  close(pi[0]);
+  buffer_init(&ba,write,pi[1],authbuf,sizeof(authbuf));
+  if (buffer_put(&ba,user,userlen) == -1) die_write();
+  if (buffer_put(&ba,pass,str_len(pass) + 1) == -1) die_write();
+  if (buffer_puts(&ba,"<") == -1) die_write();
+  if (buffer_puts(&ba,unique) == -1) die_write();
+  if (buffer_puts(&ba,hostname) == -1) die_write();
+  if (buffer_put(&ba,">",2) == -1) die_write();
+  if (buffer_flush(&ba) == -1) die_write();
+  close(pi[1]);
+  byte_zero(pass,str_len(pass));
+  byte_zero(authbuf,sizeof(authbuf));
+  if (wait_pid(&wstat,child) == -1) die();
+  if (wait_crashed(wstat)) die_childcrashed();
+  if (!stralloc_0(&auth)) die_nomem();
+  if (!stralloc_0(&protocol)) die_nomem();
+  if (wait_exitcode(wstat)) { 
+    die_badauth(); 
+    log_pop("Reject::AUTH::",auth.s,protocol.s,remoteip,remotehost,user); 
+  }
+  else
+    log_pop("Accept::AUTH::",auth.s,protocol.s,remoteip,remotehost,user); 
+  die();
+}
+
+void pop3_greet()
+{
+  char *s;
+  s = unique;
+  s += fmt_uint(s,getpid());
+  *s++ = '.';
+  s += fmt_ulong(s,(unsigned long) now());
+  *s++ = '@';
+  *s++ = 0;
+
+  if (!apop)
+    outs("+OK\r\n");
+  else {
+    outs("+OK <");
+    outs(unique);
+    outs(hostname);
+    outs(">\r\n");
+  }
+  flush();
+}
+
+void pop3_user(char *arg)
+{
+  if (stls == 2 && !seenstls) die_notls();
+  if (!*arg) { err_syntax(); return; }
+  okay();
+  seenuser = 1;
+  if (!stralloc_copys(&username,arg)) die_nomem(); 
+  if (!stralloc_0(&username)) die_nomem(); 
+}
+
+void pop3_pass(char *arg)
+{
+  if (!seenuser) { err_wantuser(); return; }
+  if (!*arg) { err_syntax(); return; }
+  if (!stralloc_copys(&auth,"User")) die_nomem();
+  doanddie(username.s,username.len,arg);
+}
+
+void pop3_apop(char *arg)
+{
+  char *space;
+
+  if (stls == 2 && !seenstls) die_notls();
+  space = arg + str_chr(arg,' ');
+  if (!*space) { err_syntax(); return; }
+  *space++ = 0;
+  if (!stralloc_copys(&auth,"Apop")) die_nomem();
+  doanddie(arg,space - arg,space);
+}
+
+void pop3_capa(char *arg)
+{
+  outs("+OK capability list follows\r\n");
+  outs("TOP\r\n");
+  outs("USER\r\n");
+  outs("UIDL\r\n");
+  if (apop)
+    outs("APOP\r\n");
+  if (stls > 0) 
+    outs("STLS\r\n");
+  outs(".\r\n");
+  flush();
+}
+
+void pop3_stls(char *arg)
+{
+  if (stls == 0 || seenstls == 1)
+    return err("STLS not available");
+  outs("+OK starting TLS negotiation\r\n");
+  flush();
+
+  if (!starttls_init()) die_tls();
+  buffer_init(&bi,saferead,FDIN,inbuf,sizeof(inbuf));
+  seenstls = 1;
+  
+/* reset state */
+  seenuser = 0;
+  if (!stralloc_cats(&protocol,"S")) die_nomem();
+}
+
+struct commands pop3commands[] = {
+  { "user", pop3_user, 0 }
+, { "pass", pop3_pass, 0 }
+, { "apop", pop3_apop, 0 }
+, { "quit", pop3_quit, 0 }
+, { "capa", pop3_capa, 0 }
+, { "stls", pop3_stls, 0 }
+, { "noop", okay, 0 }
+, { 0, err_authoriz, 0 }
+};
+
+int main(int argc,char **argv)
+{
+  char *pop3auth;
+  char *ucspitls;
+
+  sig_alarmcatch(die);
+  sig_pipeignore();
+ 
+  hostname = argv[1];
+  if (!hostname) die_usage();
+  childargs = argv + 2;
+  if (!*childargs) die_usage();
+
+  ucspitls = env_get("UCSPITLS");
+  if (ucspitls) {
+    stls = 1;
+    if (!case_diffs(ucspitls,"-")) stls = 0;
+    if (!case_diffs(ucspitls,"!")) stls = 2;
+  }
+
+  pop3auth = env_get("POP3AUTH");
+  if (pop3auth) {
+    if (case_starts(pop3auth,"apop")) apop = 2;
+    if (case_starts(pop3auth,"+apop")) apop = 1;
+  }
+  poplog_init(); 
+  pop3_greet();
+  commands(&bi,pop3commands);
+  die();
+}