From 90477edd6d3fb556f4b8b98864c4f86aca91a8ce Mon Sep 17 00:00:00 2001
From: Maalvika Bhat <42943695+maalvikabhat@users.noreply.github.com>
Date: Thu, 27 Feb 2020 21:33:57 -0500
Subject: [PATCH] finally compiles

---
 exercises/ex04/trout/util.c | 284 ++++++++++++++++++++++++++++++++++++
 1 file changed, 284 insertions(+)
 create mode 100644 exercises/ex04/trout/util.c

diff --git a/exercises/ex04/trout/util.c b/exercises/ex04/trout/util.c
new file mode 100644
index 00000000..ce9b0a40
--- /dev/null
+++ b/exercises/ex04/trout/util.c
@@ -0,0 +1,284 @@
+#include "util.h"
+
+void err_doit (int errnoflag, int level, char *fmt, va_list ap)
+{
+  int errno_save, n;
+  char buf[MAXLINE];
+
+  errno_save = errno;             /* value caller might want printed */
+  vsnprintf (buf, sizeof(buf), fmt, ap);
+  n = strnlen (buf, MAXLINE);
+  if (errnoflag)
+    snprintf (buf+n, sizeof(buf) - n, ": %s", strerror(errno_save));
+  strcat (buf, "\n");
+
+  fflush (stdout);
+  fputs (buf, stderr);
+  fflush (stderr);
+}
+
+void err_sys (char *fmt, ...)
+{
+  va_list ap;
+  va_start (ap, fmt);
+  err_doit (1, LOG_ERR, fmt, ap);
+  va_end(ap);
+  exit(1);
+}
+
+void err_quit (char *fmt, ...)
+{
+  va_list ap;
+  va_start (ap, fmt);
+  err_doit (0, LOG_ERR, fmt, ap);
+  va_end(ap);
+  exit(1);
+}
+
+char *sock_ntop_host(const struct sockaddr *sa, socklen_t salen)
+{
+  static char str[128];
+
+  switch (sa->sa_family) {
+  case AF_INET: {
+    struct sockaddr_in      *sin = (struct sockaddr_in *) sa;
+
+    if (inet_ntop(AF_INET, &sin->sin_addr, str, sizeof(str)) == NULL) {
+      return NULL;
+    } else {
+      return str;
+    }
+  }
+  case AF_UNIX: {
+    struct sockaddr_un      *unp = (struct sockaddr_un *) sa;
+    
+    /* OK to have no pathname bound to the socket: happens on
+       every connect() unless client calls bind() first. */
+    if (unp->sun_path[0] == 0)
+      strcpy(str, "(no pathname bound)");
+    else
+      snprintf(str, sizeof(str), "%s", unp->sun_path);
+    return str;
+  }
+  default:
+    snprintf(str, sizeof(str), "sock_ntop_host: unknown AF_xxx: %d, len %d",
+	     sa->sa_family, salen);
+    return str;
+  }
+  return NULL;
+}
+
+char *Sock_ntop_host(const struct sockaddr *sa, socklen_t salen)
+{
+  char *ptr;
+
+  if ( (ptr = sock_ntop_host(sa, salen)) == NULL)
+    err_sys("sock_ntop_host error");        /* inet_ntop() sets errno */
+  return(ptr);
+}
+
+void sock_set_port(struct sockaddr *sa, socklen_t salen, int port)
+{
+  switch (sa->sa_family) {
+    case AF_INET: {
+      struct sockaddr_in	*sin = (struct sockaddr_in *) sa;
+    
+      sin->sin_port = port;
+      return;
+    }
+    return;
+  }
+}
+
+int sock_cmp_addr(const struct sockaddr *sa1, const struct sockaddr *sa2,
+		  socklen_t salen)
+{
+  if (sa1->sa_family != sa2->sa_family)
+    return(-1);
+
+  switch (sa1->sa_family) {
+    case AF_INET: {
+      return(memcmp( &((struct sockaddr_in *) sa1)->sin_addr,
+		     &((struct sockaddr_in *) sa2)->sin_addr,
+		     sizeof(struct in_addr)));
+    }
+
+    case AF_UNIX: {
+      return(strcmp( ((struct sockaddr_un *) sa1)->sun_path,
+		     ((struct sockaddr_un *) sa2)->sun_path));
+    }
+  }
+  return -1;
+}
+
+void tv_sub (struct timeval *out, struct timeval *in)
+{
+  if ( (out->tv_usec -= in->tv_usec) < 0) {     /* out -= in */
+    --out->tv_sec;
+    out->tv_usec += 1000000;
+  }
+  out->tv_sec -= in->tv_sec;
+}
+
+char *icmpcode_v4(int code)
+{
+  switch (code) {
+    case  0: return("network unreachable");
+    case  1: return("host unreachable");
+    case  2: return("protocol unreachable");
+    case  3: return("port unreachable");
+    case  4: return("fragmentation required but DF bit set");
+    case  5: return("source route failed");
+    case  6: return("destination network unknown");
+    case  7: return("destination host unknown");
+    case  8: return("source host isolated (obsolete)");
+    case  9: return("destination network administratively prohibited");
+    case 10: return("destination host administratively prohibited");
+    case 11: return("network unreachable for TOS");
+    case 12: return("host unreachable for TOS");
+    case 13: return("communication administratively prohibited by filtering");
+    case 14: return("host recedence violation");
+    case 15: return("precedence cutoff in effect");
+    default: return("[unknown code]");
+  }
+}
+
+Sigfunc *signal(int signo, Sigfunc *func)
+{
+  struct sigaction act, oact;
+
+  act.sa_handler = func;
+  sigemptyset(&act.sa_mask);
+  act.sa_flags = 0;
+  if (signo == SIGALRM) {
+    act.sa_flags |= SA_INTERRUPT;     /* SunOS 4.x (and Linux, apparently) */
+  }
+  if (sigaction(signo, &act, &oact) < 0)
+    return(SIG_ERR);
+  return(oact.sa_handler);
+}
+
+Sigfunc *Signal(int signo, Sigfunc *func)	/* for our signal() function */
+{
+  Sigfunc *sigfunc;
+
+  if ( (sigfunc = signal(signo, func)) == SIG_ERR)
+    err_sys("signal error");
+  return(sigfunc);
+}
+
+void *Malloc(size_t size)
+{
+  void	*ptr;
+
+  if ( (ptr = malloc(size)) == NULL)
+    err_sys("malloc error");
+  return(ptr);
+}
+
+void *Calloc(size_t n, size_t size)
+{
+  void	*ptr;
+  
+  if ( (ptr = calloc(n, size)) == NULL)
+    err_sys("calloc error");
+  return(ptr);
+}
+
+void Gettimeofday(struct timeval *tv, void *foo)
+{
+  if (gettimeofday(tv, foo) == -1)
+    err_sys("gettimeofday error");
+  return;
+}
+
+void Pipe(int *fds)
+{
+  if (pipe(fds) < 0)
+    err_sys("pipe error");
+}
+
+void Bind(int fd, const struct sockaddr *sa, socklen_t salen)
+{
+  if (bind(fd, sa, salen) < 0)
+    err_sys("bind error");
+}
+
+void Setsockopt(int fd, int level, int optname, const void *optval,
+		socklen_t optlen)
+{
+  if (setsockopt(fd, level, optname, optval, optlen) < 0)
+    err_sys("setsockopt error");
+}
+
+struct addrinfo *
+host_serv (char *host, char *serv, int family, int socktype)
+{
+  int n;
+  struct addrinfo hints, *res;
+
+  bzero (&hints, sizeof(struct addrinfo));
+  hints.ai_flags = AI_CANONNAME;           /* return canonical name */
+  hints.ai_family = family;
+  hints.ai_socktype = socktype;
+
+  n = getaddrinfo (host, serv, &hints, &res);
+  if (n != 0) {
+    return NULL;
+  } else {
+    return res;     /* return pointer to first on linked list */
+  }
+}
+
+/*
+ * There is no easy way to pass back the integer return code from
+ * getaddrinfo() in the function above, short of adding another argument
+ * that is a pointer, so the easiest way to provide the wrapper function
+ * is just to duplicate the simple function as we do here.
+ */
+
+struct addrinfo *
+Host_serv(const char *host, const char *serv, int family, int socktype)
+{
+  int n;
+  struct addrinfo hints, *res;
+
+  bzero(&hints, sizeof(struct addrinfo));
+  hints.ai_flags = AI_CANONNAME;  /* always return canonical name */
+  hints.ai_family = family;               /* 0, AF_INET, AF_INET6, etc. */
+  hints.ai_socktype = socktype;   /* 0, SOCK_STREAM, SOCK_DGRAM, etc. */
+
+  if ( (n = getaddrinfo(host, serv, &hints, &res)) != 0)
+    err_quit("host_serv error for %s, %s: %s",
+	     (host == NULL) ? "(no hostname)" : host,
+	     (serv == NULL) ? "(no service name)" : serv,
+	     gai_strerror(n));
+
+  return(res);    /* return pointer to first on linked list */
+}
+
+ssize_t Read(int fd, void *ptr, size_t nbytes)
+{
+  ssize_t n;
+ 
+  if ( (n = read(fd, ptr, nbytes)) == -1)
+    err_sys("read error");
+  return(n);
+}
+
+void Write(int fd, void *ptr, size_t nbytes)
+{
+  if (write(fd, ptr, nbytes) != nbytes)
+    err_sys("write error");
+}
+
+ssize_t Recvfrom(int fd, void *ptr, size_t nbytes, int flags,
+		 struct sockaddr *sa, socklen_t *salenptr)
+{
+  ssize_t n;
+
+  n = recvfrom(fd, ptr, nbytes, flags, sa, salenptr);
+  if (n < 0)
+    err_sys("recvfrom error");
+  return(n);
+}