GCC won't compile program - c

Question

Alright, so I'm going crazy over this one. I'm currently trying to go through Hacking: Art of Exploitation and I'm on the part about socket programming. So here is the code and the compiler output below it.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "hacking.h"
#define PORT 7890 // the port users will be connecting to
int main(void) {
int sockfd, new_sockfd; // listen on sock_fd, new connection on new_fd
struct sockaddr_in host_addr, client_addr; // my address information
socklen_t sin_size;
int recv_length=1, yes=1;
char buffer[1024];
if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) == -1)
fatal("in socket");
if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) == -1)
fatal("setting socket option SO_REUSEADDR");
host_addr.sin_family = AF_INET; // host byte order
host_addr.sin_port = htons(PORT); // short, network byte order
host_addr.sin_addr.s_addr = INADDR_ANY; // automatically fill with my IP
memset(&(host_addr.sin_zero), '\0', 8); // zero the rest of the struct
if (bind(sockfd, (struct sockaddr *)&host_addr, sizeof(struct sockaddr)) == -1)
fatal("binding to socket");
if (listen(sockfd, 5) == -1)
fatal("listening on socket");
while(1) { // Accept loop
sin_size = sizeof(struct sockaddr_in);
new_sockfd = accept(sockfd, (struct sockaddr *)&client_addr, &sin_size);
if(new_sockfd == -1)
fatal("accepting connection");
printf("server: got connection from %s port %d\n",inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
send(new_sockfd, "Hello World!\n", 13, 0);
recv_length = recv(new_sockfd, &buffer, 1024, 0);
while(recv_length > 0) {
printf("RECV: %d bytes\n", recv_length);
dump(buffer, recv_length);
recv_length = recv(new_sockfd, &buffer, 1024, 0);
}
close(new_sockfd);
}
return 0;
}
Compiler output:
root#root-laptop:~ $ gcc simple_server.c
In file included from /usr/include/sys/socket.h:35,
from simple_server.c:7:
/usr/include/bits/socket.h:122: error: syntax error before "define"
In file included from /usr/include/sys/socket.h:35,
from simple_server.c:7:
/usr/include/bits/socket.h:147: error: syntax error before "sa_family_t"
/usr/include/bits/socket.h:149: error: syntax error before '}' token
/usr/include/bits/socket.h:164: error: syntax error before "sa_family_t"
/usr/include/bits/socket.h:167: error: syntax error before '}' token
In file included from simple_server.c:9:
/usr/include/netinet/in.h:221: error: syntax error before "sa_family_t"
/usr/include/netinet/in.h:226: error: invalid application of `sizeof' to an incomplete type
/usr/include/netinet/in.h:229: error: size of array `sin_zero' is too large
/usr/include/netinet/in.h:230: error: syntax error before '}' token
/usr/include/netinet/in.h:235: error: syntax error before "sa_family_t"
/usr/include/netinet/in.h:240: error: syntax error before '}' token
/usr/include/netinet/in.h:283: error: field `gr_group' has incomplete type
/usr/include/netinet/in.h:292: error: field `gsr_group' has incomplete type
/usr/include/netinet/in.h:295: error: field `gsr_source' has incomplete type
/usr/include/netinet/in.h:327: error: field `gf_group' has incomplete type
/usr/include/netinet/in.h:335: error: field `gf_slist' has incomplete type
In file included from simple_server.c:9:
/usr/include/netinet/in.h:465: error: field `ip6m_addr' has incomplete type
simple_server.c: In function `main':
simple_server.c:17: error: storage size of `host_addr' isn't known
simple_server.c:17: error: storage size of `client_addr' isn't known
simple_server.c:34: error: invalid application of `sizeof' to an incomplete type
simple_server.c:41: error: invalid application of `sizeof' to an incomplete type
simple_server.c: At top level:
/usr/include/netinet/in.h:229: error: storage size of `sin_zero' isn't known
For some reason GCC isn't finding the predefined struct in the header files. I've tried everything to fix this, from removing header files to adding only certain ones.
Also I should note that I'm using the VM image that came with the book. It's an old version of Ubuntu and GCC.
Edit:
Here are the requested files.
socket.h
#ifndef __BITS_SOCKET_H
#define __BITS_SOCKET_H
#if !defined _SYS_SOCKET_H && !defined _NETINET_IN_H
# error "Never include <bits/socket.h> directly; use <sys/socket.h> instead."
#endif
#define __need_size_t
#define __need_NULL
#include <stddef.h>
#include <limits.h>
#include <sys/types.h>
/* Type for length arguments in socket calls. */
#ifndef __socklen_t_defined
typedef __socklen_t socklen_t;
# define __socklen_t_defined
#endif
/* Types of sockets. */
enum __socket_type
{
SOCK_STREAM = 1, /* Sequenced, reliable, connection-based
byte streams. */
#define SOCK_STREAM SOCK_STREAM
SOCK_DGRAM = 2, /* Connectionless, unreliable datagrams
of fixed maximum length. */
#define SOCK_DGRAM SOCK_DGRAM
SOCK_RAW = 3, /* Raw protocol interface. */
#define SOCK_RAW SOCK_RAW
SOCK_RDM = 4, /* Reliably-delivered messages. */
#define SOCK_RDM SOCK_RDM
SOCK_SEQPACKET = 5, /* Sequenced, reliable, connection-based,
datagrams of fixed maximum length. */
#define SOCK_SEQPACKET SOCK_SEQPACKET
SOCK_PACKET = 10 /* Linux specific way of getting packets
at the dev level. For writing rarp and
other similar things on the user level. */
#define SOCK_PACKET SOCK_PACKET
};
/* Protocol families. */
#define PF_UNSPEC 0 /* Unspecified. */
#define PF_LOCAL 1 /* Local to host (pipes and file-domain). */
#define PF_UNIX PF_LOCAL /* Old BSD name for PF_LOCAL. */
#define PF_FILE PF_LOCAL /* Another non-standard name for PF_LOCAL. */
#define PF_INET 2 /* IP protocol family. */
#define PF_AX25 3 /* Amateur Radio AX.25. */
#define PF_IPX 4 /* Novell Internet Protocol. */
#define PF_APPLETALK 5 /* Appletalk DDP. */
#define PF_NETROM 6 /* Amateur radio NetROM. */
#define PF_BRIDGE 7 /* Multiprotocol bridge. */
#define PF_ATMPVC 8 /* ATM PVCs. */
#define PF_X25 9 /* Reserved for X.25 project. */
#define PF_INET6 10 /* IP version 6. */
#define PF_ROSE 11 /* Amateur Radio X.25 PLP. */
#define PF_DECnet 12 /* Reserved for DECnet project. */
#define PF_NETBEUI 13 /* Reserved for 802.2LLC project. */
#define PF_SECURITY 14 /* Security callback pseudo AF. */
#define PF_KEY 15 /* PF_KEY key management API. */
#define PF_NETLINK 16
#define PF_ROUTE PF_NETLINK /* Alias to emulate 4.4BSD. */
#define PF_PACKET 17 /* Packet family. */
#define PF_ASH 18 /* Ash. */
#define PF_ECONET 19 /* Acorn Econet. */
#define PF_ATMSVC 20 /* ATM SVCs. */
#define PF_SNA 22 /* Linux SNA Project */
#define PF_IRDA 23 /* IRDA sockets. */
#define PF_PPPOX 24 /* PPPoX sockets. */
#define PF_WANPIPE 25 /* Wanpipe API sockets. */
#define PF_BLUETOOTH 31 /* Bluetooth sockets. */
#define PF_MAX 32 /* For now.. */
/* Address families. */
#define AF_UNSPEC PF_UNSPEC
#define AF_LOCAL PF_LOCAL
#define AF_UNIX PF_UNIX
#define AF_FILE PF_FILE
#define AF_INET PF_INET
#define AF_AX25 PF_AX25
#define AF_IPX PF_IPX
#define AF_APPLETALK PF_APPLETALK
#define AF_NETROM PF_NETROM
#define AF_BRIDGE PF_BRIDGE
#define AF_ATMPVC PF_ATMPVC
#define AF_X25 PF_X25
#define AF_INET6 PF_INET6
#define AF_ROSE PF_ROSE
#define AF_DECnet PF_DECnet
#define AF_NETBEUI PF_NETBEUI
#define AF_SECURITY PF_SECURITY
#define AF_KEY PF_KEY
#define AF_NETLINK PF_NETLINK
#define AF_ROUTE PF_ROUTE
#define AF_PACKET PF_PACKET
#define AF_ASH PF_ASH
#define AF_ECONET PF_ECONET
#define AF_ATMSVC PF_ATMSVC
#define AF_SNA PF_SNA
#define AF_IRDA PF_IRDA
#define AF_PPPOX PF_PPPOX
o define AF_WANPIPE PF_WANPIPE
#define AF_BLUETOOTH PF_BLUETOOTH
#define AF_MAX PF_MAX
/* Socket level values. Others are defined in the appropriate headers.
XXX These definitions also should go into the appropriate headers as
far as they are available. */
#define SOL_RAW 255
#define SOL_DECNET 261
#define SOL_X25 262
#define SOL_PACKET 263
#define SOL_ATM 264 /* ATM layer (cell level). */
#define SOL_AAL 265 /* ATM Adaption Layer (packet level). */
#define SOL_IRDA 266
/* Maximum queue length specifiable by listen. */
#define SOMAXCONN 128
/* Get the definition of the macro to define the common sockaddr members. */
#include <bits/sockaddr.h>
/* Structure describing a generic socket address. */
struct sockaddr
{
__SOCKADDR_COMMON (sa_); /* Common data: address family and length. */
char sa_data[14]; /* Address data. */
};
/* Structure large enough to hold any socket address (with the historical
exception of AF_UNIX). We reserve 128 bytes. */
#if ULONG_MAX > 0xffffffff
# define __ss_aligntype __uint64_t
#else
# define __ss_aligntype __uint32_t
#endif
#define _SS_SIZE 128
#define _SS_PADSIZE (_SS_SIZE - (2 * sizeof (__ss_aligntype)))
struct sockaddr_storage
{
__SOCKADDR_COMMON (ss_); /* Address family, etc. */
__ss_aligntype __ss_align; /* Force desired alignment. */
char __ss_padding[_SS_PADSIZE];
};
/* Bits in the FLAGS argument to `send', `recv', et al. */
enum
{
MSG_OOB = 0x01, /* Process out-of-band data. */
#define MSG_OOB MSG_OOB
MSG_PEEK = 0x02, /* Peek at incoming messages. */
#define MSG_PEEK MSG_PEEK
MSG_DONTROUTE = 0x04, /* Don't use local routing. */
#define MSG_DONTROUTE MSG_DONTROUTE
#ifdef __USE_GNU
/* DECnet uses a different name. */
MSG_TRYHARD = MSG_DONTROUTE,
# define MSG_TRYHARD MSG_DONTROUTE
#endif
MSG_CTRUNC = 0x08, /* Control data lost before delivery. */
#define MSG_CTRUNC MSG_CTRUNC
MSG_PROXY = 0x10, /* Supply or ask second address. */
#define MSG_PROXY MSG_PROXY
MSG_TRUNC = 0x20,
#define MSG_TRUNC MSG_TRUNC
MSG_DONTWAIT = 0x40, /* Nonblocking IO. */
#define MSG_DONTWAIT MSG_DONTWAIT
MSG_EOR = 0x80, /* End of record. */
#define MSG_EOR MSG_EOR
MSG_WAITALL = 0x100, /* Wait for a full request. */
#define MSG_WAITALL MSG_WAITALL
MSG_FIN = 0x200,
#define MSG_FIN MSG_FIN
MSG_SYN = 0x400,
#define MSG_SYN MSG_SYN
MSG_CONFIRM = 0x800, /* Confirm path validity. */
#define MSG_CONFIRM MSG_CONFIRM
MSG_RST = 0x1000,
#define MSG_RST MSG_RST
MSG_ERRQUEUE = 0x2000, /* Fetch message from error queue. */
#define MSG_ERRQUEUE MSG_ERRQUEUE
MSG_NOSIGNAL = 0x4000, /* Do not generate SIGPIPE. */
#define MSG_NOSIGNAL MSG_NOSIGNAL
MSG_MORE = 0x8000 /* Sender will send more. */
#define MSG_MORE MSG_MORE
};
/* Structure describing messages sent by
`sendmsg' and received by `recvmsg'. */
struct msghdr
{
void *msg_name; /* Address to send to/receive from. */
socklen_t msg_namelen; /* Length of address data. */
struct iovec *msg_iov; /* Vector of data to send/receive into. */
size_t msg_iovlen; /* Number of elements in the vector. */
void *msg_control; /* Ancillary data (eg BSD filedesc passing). */
size_t msg_controllen; /* Ancillary data buffer length.
!! The type should be socklen_t but the
definition of the kernel is incompatible
with this. */
int msg_flags; /* Flags on received message. */
};
/* Structure used for storage of ancillary data object information. */
struct cmsghdr
{
size_t cmsg_len; /* Length of data in cmsg_data plus length
of cmsghdr structure.
!! The type should be socklen_t but the
definition of the kernel is incompatible
with this. */
int cmsg_level; /* Originating protocol. */
int cmsg_type; /* Protocol specific type. */
#if (!defined __STRICT_ANSI__ && __GNUC__ >= 2) || __STDC_VERSION__ >= 199901L
__extension__ unsigned char __cmsg_data __flexarr; /* Ancillary data. */
#endif
};
/* Ancillary data object manipulation macros. */
#if (!defined __STRICT_ANSI__ && __GNUC__ >= 2) || __STDC_VERSION__ >= 199901L
# define CMSG_DATA(cmsg) ((cmsg)->__cmsg_data)
#else
# define CMSG_DATA(cmsg) ((unsigned char *) ((struct cmsghdr *) (cmsg) + 1))
#endif
#define CMSG_NXTHDR(mhdr, cmsg) __cmsg_nxthdr (mhdr, cmsg)
#define CMSG_FIRSTHDR(mhdr) \
((size_t) (mhdr)->msg_controllen >= sizeof (struct cmsghdr) \
? (struct cmsghdr *) (mhdr)->msg_control : (struct cmsghdr *) NULL)
#define CMSG_ALIGN(len) (((len) + sizeof (size_t) - 1) \
& (size_t) ~(sizeof (size_t) - 1))
#define CMSG_SPACE(len) (CMSG_ALIGN (len) \
+ CMSG_ALIGN (sizeof (struct cmsghdr)))
#define CMSG_LEN(len) (CMSG_ALIGN (sizeof (struct cmsghdr)) + (len))
extern struct cmsghdr *__cmsg_nxthdr (struct msghdr *__mhdr,
struct cmsghdr *__cmsg) __THROW;
#ifdef __USE_EXTERN_INLINES
# ifndef _EXTERN_INLINE
# define _EXTERN_INLINE extern __inline
# endif
_EXTERN_INLINE struct cmsghdr *
__NTH (__cmsg_nxthdr (struct msghdr *__mhdr, struct cmsghdr *__cmsg))
{
if ((size_t) __cmsg->cmsg_len < sizeof (struct cmsghdr))
/* The kernel header does this so there may be a reason. */
return 0;
__cmsg = (struct cmsghdr *) ((unsigned char *) __cmsg
+ CMSG_ALIGN (__cmsg->cmsg_len));
if ((unsigned char *) (__cmsg + 1) > ((unsigned char *) __mhdr->msg_control
+ __mhdr->msg_controllen)
|| ((unsigned char *) __cmsg + CMSG_ALIGN (__cmsg->cmsg_len)
> ((unsigned char *) __mhdr->msg_control + __mhdr->msg_controllen)))
/* No more entries. */
return 0;
return __cmsg;
}
#endif /* Use `extern inline'. */
/* Socket level message types. This must match the definitions in
<linux/socket.h>. */
enum
{
SCM_RIGHTS = 0x01 /* Transfer file descriptors. */
#define SCM_RIGHTS SCM_RIGHTS
#ifdef __USE_BSD
, SCM_CREDENTIALS = 0x02 /* Credentials passing. */
# define SCM_CREDENTIALS SCM_CREDENTIALS
#endif
};
/* User visible structure for SCM_CREDENTIALS message */
struct ucred
{
pid_t pid; /* PID of sending process. */
uid_t uid; /* UID of sending process. */
gid_t gid; /* GID of sending process. */
};
/* Get socket manipulation related informations from kernel headers. */
#include <asm/socket.h>
/* Structure used to manipulate the SO_LINGER option. */
struct linger
{
int l_onoff; /* Nonzero to linger on close. */
int l_linger; /* Time to linger. */
};
#endif /* bits/socket.h */
hacking.h
#include <stdlib.h>
//This function is used to display packet data by the server program.
void dump(const unsigned char *data_buffer, const unsigned int length){
unsigned char byte;
unsigned int i, j;
for(i = 0; i < length; i++){
byte = data_buffer[i];
printf("%02x ", data_buffer[i]); //Display byte in hex
if((( i % 16) == 15 ) || ( i == length - 1)) {
for( j = 0; j < 15 - ( i % 16 ); j++ )
printf(" ");
printf("| ");
for(j = ( i - ( i % 16 )); j <= i; j++) { //Display printable bytes from line.
byte = data_buffer[j];
if((byte > 31) && (byte < 127))//Outside printable char range
printf("%c", byte);
else
printf(".");
}
printf("\n"); // End of the dump line (each line is 16 bytes)
}//End if
}//End for
}
void fatal(char *message){
char error_message[100];
strcpy(error_message, "[!!] Fatal Error");
strncat(error_message, message, 83);
perror(error_message);
exit(-1);
}
void *ec_malloc(unsigned int size){
void *ptr;
ptr = malloc(size);
if(ptr== NULL)
fatal("in ec_malloc() on memory allocation");
return ptr;
}
in.h
https://pastebin.com/RTjSdA2e

Answer 1

Ok. So the problem was in socket.h. Basically this line
o define AF_WANPIPE PF_WANPIPE
needed to be changed to this
#define AF_WANPIPE PF_WANPIPE
Thanks David Wohlferd.

Answer 2

the contents of the hacking.h header file are not correct.
The contents should be the 'prototypes' for those functions and the actual functions should be in a separate .c file, probably named hacking.c
I.E. the contents of the hacking.h file should be:
#ifndef HACKING_H
#define HACKING_H
//This function is used to display packet data by the server program.
void dump(const unsigned char *data_buffer, const unsigned int length);
void fatal(char *message);
void *ec_malloc(unsigned int size);
#endif // HACKING_H
Notice the 'include only once' wrapper; consisting of the #ifndef, #define, and the trailing #endif statements
notice the file only contains the prototypes (it could also contain any other #define statements and/or data definitions and/or macro definitions, although in this case there are none.)
Then there should be a separate file hacking.c that contains the actual functions (and a statement: #include "hacking.h")
in general, neither function bodies nor data declarations should be in a header file. (later on, you will learn of certain exceptions to this statement, like when declaring inline functions