Client listener in place, not functional yet except for ability to accept connections

1 files changed, 140 insertions, 57 deletions

diff --git a/blabouncer.c b/blabouncer.c
index 49e8f4b..ccbfa13 100644
--- a/blabouncer.c
+++ b/blabouncer.c
@@ -15,6 +15,9 @@
 
 #define MAXDATASIZE 513 // max number of bytes we can get at once (RFC2812 says 512, plus one for null terminator)
 #define STDIN 0 // stdin is fd 0
+#define BACKLOG 10 // maximum length to which the queue of pending connections for sockfd may grow
+
+#define BOUNCERLISTENPORT "1234" // TODO: change this to a config option!
 
 // getstdin() return codes
 #define OK       0
@@ -38,7 +41,7 @@ static int getstdin(char *prompt, char *buff, size_t sz) {
 
   // If it was too long, there'll be no newline. In that case, we flush
   // to end of line so that excess doesn't affect the next call.
-  if (buff[strlen(buff)-1] != '\n') { // strlen of the actually entered line, not the original array size
+  if (buff[strlen(buff) - 1] != '\n') { // strlen of the actually entered line, not the original array size
     extra = 0;
     while (((ch = getchar()) != '\n') && (ch != EOF)) {
       extra = 1;
@@ -47,7 +50,7 @@ static int getstdin(char *prompt, char *buff, size_t sz) {
   }
 
   // Otherwise remove newline and give string back to caller.
-  buff[strlen(buff)-1] = '\0';
+  buff[strlen(buff) - 1] = '\0';
   return OK;
 }
 
@@ -65,8 +68,7 @@ void appendcrlf(char *string) {
 }
 
 // get sockaddr, IPv4 or IPv6:
-void *get_in_addr(struct sockaddr *sa)
-{
+void *get_in_addr(struct sockaddr *sa) {
   if (sa->sa_family == AF_INET) {
     return &(((struct sockaddr_in*)sa)->sin_addr);
   }
@@ -74,7 +76,122 @@ void *get_in_addr(struct sockaddr *sa)
   return &(((struct sockaddr_in6*)sa)->sin6_addr);
 }
 
-void dochat(int *sockfd, char *buf) {
+int createserversocket(char *host, char *port) {
+  int sockfd;
+  struct addrinfo hints, *servinfo, *p;
+  int rv;// return value for getaddrinfo (for error message)
+  char s[INET6_ADDRSTRLEN];
+
+  memset(&hints, 0, sizeof hints);
+  hints.ai_family = AF_UNSPEC;
+  hints.ai_socktype = SOCK_STREAM;
+
+  if ((rv = getaddrinfo(host, port, &hints, &servinfo)) != 0) {
+    fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
+    return 1;
+  }
+
+  // loop through all the results and connect to the first we can
+  for (p = servinfo; p != NULL; p = p->ai_next) {
+    if ((sockfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1) {
+      perror("bouncer-server: socket");
+      continue;
+    }
+
+    if (connect(sockfd, p->ai_addr, p->ai_addrlen) == -1) {
+      close(sockfd);
+      perror("bouncer-server: connect");
+      continue;
+    }
+
+    break;
+  }
+
+  if (p == NULL) {
+    fprintf(stderr, "bouncer-server: failed to connect\n");
+    return 2;
+  }
+
+  inet_ntop(p->ai_family, get_in_addr((struct sockaddr *)p->ai_addr), s, sizeof s);
+  printf("bouncer-server: connecting to %s\n", s);
+
+  freeaddrinfo(servinfo); // all done with this structure
+
+  return sockfd;
+}
+
+int createclientsocket(char *listenport) {
+  listenport = BOUNCERLISTENPORT;
+
+  int listener;     // listening socket descriptor
+
+  int rv; // return value for getaddrinfo (for error message)
+
+	struct addrinfo hints, *ai, *p;
+
+	// get us a socket and bind it
+	memset(&hints, 0, sizeof hints);
+	hints.ai_family = AF_UNSPEC;
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_flags = AI_PASSIVE;
+
+	if ((rv = getaddrinfo(NULL, listenport, &hints, &ai)) != 0) {
+		fprintf(stderr, "selectserver: %s\n", gai_strerror(rv));
+		exit(1);
+	}
+
+  // Try for IPv6
+	for (p = ai; p != NULL; p = p->ai_next) {
+    if (p->ai_family == AF_INET6) {
+      listener = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
+      if (listener != -1) {
+        // success, got IPv6!
+        printf("success, got IPv6!  ai_family: %d\n", p->ai_family);
+        break;
+      }
+    }
+  }
+
+  // Try for IPv4 if IPv6 failed
+  if (listener < 0) {
+    for (p = ai; p != NULL; p = p->ai_next) {
+      if (p->ai_family == AF_INET) {
+        listener = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
+        if (listener != -1) {
+          // moderate success, got IPv4!
+          printf("moderate success, got IPv4!  ai_family: %d\n", p->ai_family);
+          break;
+        }
+      }
+    }
+  }
+
+  if (bind(listener, p->ai_addr, p->ai_addrlen) < 0) {
+    // failed to bind
+    close(listener);
+    printf("bouncer-client: failed to bind, exiting...\n");
+    exit(1);
+  }
+
+	// if we got here, it means we didn't get bound
+	if (p == NULL) {
+		fprintf(stderr, "selectserver: failed to bind\n");
+		exit(2);
+	}
+
+	freeaddrinfo(ai); // all done with this
+
+    // listen
+    if (listen(listener, BACKLOG) == -1) {
+        perror("listen");
+        exit(1);
+    }
+
+  return listener;
+}
+
+void dochat(int *serversockfd, int *clientsockfd) {
+  char serverbuf[MAXDATASIZE];
   int numbytes; // Number of bytes received from remote server
   char outgoingmsg[MAXDATASIZE]; // String to send to server
   int outgoingmsgrc; // Return code from getstdin() for outgoing message
@@ -85,18 +202,20 @@ void dochat(int *sockfd, char *buf) {
     FD_ZERO(&rfds); // clear entries from fd set
 
     FD_SET(STDIN, &rfds); // add STDIN (fd 0) to read fds to monitor
-    FD_SET(*sockfd, &rfds); // add our network socket ''
+    FD_SET(*serversockfd, &rfds); // add our network socket to monitor
 
-    if (select(*sockfd + 1, &rfds, NULL, NULL, NULL) < 0) { // network socket + 1, rfds, no writes, no exceptions/errors, no timeout
+    // TODO - Change this to use number of fds + 1 instead of sockfd + 1 (I don't think they will be the same with multiple sockets/connections)
+    if (select(*serversockfd + 1, &rfds, NULL, NULL, NULL) < 0) { // network socket + 1, rfds, no writes, no exceptions/errors, no timeout
       printf("receive error, exiting!?\n");
       perror("select");
-      // TODO exit here?
+      // TODO exit here?  let's try it.
+      exit(1);
     }
 
-    if (FD_ISSET(*sockfd, &rfds)) {
+    if (FD_ISSET(*serversockfd, &rfds)) {
       printf("reading socket!\n");
 
-      if ((numbytes = recv(*sockfd, buf, MAXDATASIZE - 1, 0)) == -1) {
+      if ((numbytes = recv(*serversockfd, serverbuf, MAXDATASIZE - 1, 0)) == -1) {
         printf("receive error (-1), exiting...\n");
         perror("recv");
         exit(1);
@@ -105,9 +224,9 @@ void dochat(int *sockfd, char *buf) {
         perror("recv");
         exit(1);
       }
-      buf[numbytes] = '\0';
+      serverbuf[numbytes] = '\0';
 
-      printf("RECEIVED: %s\n",buf);
+      printf("RECEIVED: %s\n", serverbuf);
     }
 
     if (FD_ISSET(STDIN, &rfds)) {
@@ -123,7 +242,7 @@ void dochat(int *sockfd, char *buf) {
 
       appendcrlf(outgoingmsg);
 
-      if (send(*sockfd, outgoingmsg, strlen(outgoingmsg), 0) == -1) {
+      if (send(*serversockfd, outgoingmsg, strlen(outgoingmsg), 0) == -1) {
         printf("send error, exiting...\n");
         perror("send");
       }
@@ -132,63 +251,27 @@ void dochat(int *sockfd, char *buf) {
 }
 
 int main(int argc, char *argv[]) {
-  // TODO: see if any of this can be shared (i.e. 1. avoid code duplication, and 2. see if variables can be shared between client/server sockets)
-
-  // I will try to keep to the notion of "server" meaning the real IRCd, "bouncer" meaning the bouncer, and "client" meaning the real IRC client
-
-  // BOUNCER-TO-SERVER socket things
-
-  int sockfd;
-  char buf[MAXDATASIZE];
-  struct addrinfo hints, *servinfo, *p;
-  int rv;
-  char s[INET6_ADDRSTRLEN];
-
   if (argc != 3) {
     fprintf(stderr,"usage: %s [hostname] [port]\n", argv[0]);
     exit(1);
   }
 
-  memset(&hints, 0, sizeof hints);
-  hints.ai_family = AF_UNSPEC;
-  hints.ai_socktype = SOCK_STREAM;
-
-  if ((rv = getaddrinfo(argv[1], argv[2], &hints, &servinfo)) != 0) {
-    fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
-    return 1;
-  }
-
-  // loop through all the results and connect to the first we can
-  for (p = servinfo; p != NULL; p = p->ai_next) {
-    if ((sockfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1) {
-      perror("bouncer-server: socket");
-      continue;
-    }
-
-    if (connect(sockfd, p->ai_addr, p->ai_addrlen) == -1) {
-      close(sockfd);
-      perror("bouncer-server: connect");
-      continue;
-    }
+  // TODO: see if any of this can be shared (i.e. 1. avoid code duplication, and 2. see if variables can be shared between client/server sockets)
 
-    break;
-  }
+  // TODO: track fdmax
 
-  if (p == NULL) {
-    fprintf(stderr, "bouncer-server: failed to connect\n");
-    return 2;
-  }
+  // I will try to keep to the notation of "server" meaning the real IRCd, "bouncer" meaning the bouncer, and "client" meaning the real IRC client
 
-  inet_ntop(p->ai_family, get_in_addr((struct sockaddr *)p->ai_addr), s, sizeof s);
-  printf("bouncer-server: connecting to %s\n", s);
+  // BOUNCER-TO-SERVER socket things
 
-  freeaddrinfo(servinfo); // all done with this structure
+  int serversockfd = createserversocket(argv[1], argv[2]);
+  int clientsockfd = createclientsocket(BOUNCERLISTENPORT);
 
-  dochat(&sockfd, buf);
+  dochat(&serversockfd, &clientsockfd);
 
   printf("dochat() complete, closing socket...\n");
 
-  close(sockfd);
+  close(serversockfd);
 
   return 0;
 }