[Help] libnids compilation Error

[Help] libnids compilation error-Linux general technology-Linux programming and kernel information. The following is a detailed description. I use fedora 7. After libpcap libnet libnids is installed,
The following code compilation error is executed on the terminal
# Gcc-o ip. c-l nids-l pcap-l net

Error message:

Ip. c: 26: Error: expected ':', '}' or '_ attribute _ 'before'. 'token
Ip. c: In the 'ICMP _ protocol_packet_callback' function:
Ip. c: 108: Error: 'struct icmp_header 'does not have a member named 'ICMP _ sequence'
Ip. c: 109: Error: 'struct icmp_header 'does not have a member named 'hun'
Ip. c: 115: Error: 'struct icmp_header 'does not have a member named 'hun'
Ip. c: 116: Error: 'struct icmp_header 'does not have a member named 'ICMP _ sequence'
Ip. c: In the 'IP _ callback' function:
Ip. c: 313: Warning: transfer parameter 1 (which belongs to 'IP _ protocol_packet_callback') to convert between incompatible pointer types
Ip. c: In the 'main' function:
Ip. c: 322: Warning: The return type of 'main' is not 'int'


I am surprised that the hun variable is not displayed in the code, and the icmp_sequence variable is also included in the icmp_header structure defined at the beginning.
The other 26 lines are correct syntax, but the error prompt says there is a missing front:; and so on, let me feel helpless...

Help everyone !!


The ip. c code is as follows:
(This code can be downloaded and changed to ip. c .)

CODE: # include "nids. h" # Include "pcap. h" # Include "libnet. h" /* Bytes ----------------------------------------------------------------------------------------------------------------------- Data Structure of the UDP protocol header Bytes ----------------------------------------------------------------------------------------------------------------------- */ Struct udp_header { Unsigned short udp_source_port; Unsigned short udp_destination_port; Unsigned short udp_length; Unsigned short udp_checksum; }; /* Bytes ----------------------------------------------------------------------------------------------------------------------- Data Structure of the ICMP protocol header Bytes ----------------------------------------------------------------------------------------------------------------------- */ Struct icmp_header { Unsigned int icmp_type; Unsigned int icmp_code; Unsigned char icmp_checksum; Unsigned char icmp_id; Unsigned char icmp_sequence; }; /* Bytes ----------------------------------------------------------------------------------------------------------------------- Data Structure of the IP protocol header Bytes ----------------------------------------------------------------------------------------------------------------------- */ Struct ip_header { # If defined (WORDS_BIGENDIAN) Unsigned char ip_version: 4,/* version */ Ip_header_length: 4;/* Header Length */ # Else Unsigned char ip_header_length: 4, ip_version: 4; # Endif Unsigned char ip_tos;/* service type */ Unsigned short ip_length;/* total length */ Unsigned short ip_id;/* ID */ Unsigned short ip_off;/* flag and offset */ Unsigned char ip_ttl;/* survival time */ Unsigned char ip_protocol;/* protocol type */ Unsigned short ip_checksum;/* checksum */ Struct in_addr ip_souce_address;/* Source IP Address */ Struct in_addr ip_destination_address;/* destination IP address */ }; /* Bytes ----------------------------------------------------------------------------------------------------------------------- TCP protocol header Bytes ----------------------------------------------------------------------------------------------------------------------- */ Struct tcp_header { Unsigned char tcp_source_port;/* Source Port Number */ Unsigned char tcp_destination_port;/* destination port number */ Unsigned short tcp_sequence;/* learn the column Code */ Unsigned short tcp_acknowledgement;/* confirmation number */ # Ifdef WORDS_BIGENDIAN Unsigned int tcp_offset: 4,/* Data offset */ Tcp_reserved: 4;/* Reserved */ # Else Unsigned int tcp_reserved: 4,/* Reserved */ Tcp_offset: 4;/* Data offset */ # Endif Unsigned int tcp_flags;/* flag */ Unsigned char tcp_windows;/* window size */ Unsigned char tcp_checksum;/* checksum */ Unsigned char tcp_urgent_pointer;/* Emergency pointer */ }; Char ascii_string [10000]; Char * char_to_ascii (char ch) { Char * string; Ascii_string [0] = 0; String = ascii_string; If (isgraph (ch )) * String ++ = ch; Else if (ch = '') * String ++ = ch; Else if (ch = '\ n' | ch =' \ R ') * String ++ = ch; Else * String ++ = '.'; * String = 0; Return ascii_string; } /* ========================================================== ========================================================== ======================================================== The following describes the ICMP functions. ========================================================== ========================================================== ======================================================== */ Void icmp_protocol_packet_callback (const u_char * packet_content) { Struct icmp_header * icmp_protocol; Icmp_protocol = (struct icmp_header *) (packet_content + 14 + 20 ); Printf ("---------- ICMP protocol ---------- \ n "); Printf ("ICMP Type: % d \ n", icmp_protocol-> icmp_type ); Switch (icmp_protocol-> icmp_type)/* ICMP type */ { Case 8: Printf ("ICMP Echo Request Protocol \ n "); Printf ("ICMP code: % d \ n", icmp_protocol-> icmp_code ); Printf ("sequence code: % d \ n", icmp_protocol-> icmp_sequence ); Printf ("identifier: % d \ n", icmp_protocol-> icmp_id ); Break; Case 0: Printf ("ICMP echo response protocol \ n "); Printf ("ICMP code: % d \ n", icmp_protocol-> icmp_code ); Printf ("identifier: % d \ n", icmp_protocol-> icmp_id ); Printf ("sequence code: % d \ n", icmp_protocol-> icmp_sequence ); Break; Default: Break; } Printf ("ICMP checksum: % d \ n", ntohs (icmp_protocol-> icmp_checksum);/* Get the checksum */ Return; } /* ========================================================== ========================================================== ======================================================== The following is a function for analyzing the TCP protocol. ========================================================== ========================================================== ======================================================== */ Void tcp_protocol_packet_callback (const u_char * packet_content) { Struct tcp_header * tcp_protocol; U_char flags; Int header_length; U_short source_port; U_short destination_port; U_short windows; U_short urgent_pointer; U_int sequence; U_int acknowledgement; Unsigned char checksum; Tcp_protocol = (struct tcp_header *) (packet_content + 14 + 20 ); Source_port = ntohs (tcp_protocol-> tcp_source_port ); /* Obtain the source port number */ Destination_port = ntohs (tcp_protocol-> tcp_destination_port ); /* Obtain the destination port number */ Header_length = tcp_protocol-> tcp_offset * 4; /* Obtain the header length */ Sequence = ntohl (tcp_protocol-> tcp_sequence ); /* Obtain the sequence code */ Acknowledgement = ntohl (tcp_protocol-> tcp_acknowledgement ); /* Get the confirmation number */ Windows = ntohs (tcp_protocol-> tcp_windows ); /* Obtain the window size */ Urgent_pointer = ntohs (tcp_protocol-> tcp_urgent_pointer ); /* Get the emergency pointer */ Flags = tcp_protocol-> tcp_flags; Checksum = ntohs (tcp_protocol-> tcp_checksum ); Printf ("------- TCP protocol ------- \ n "); Printf ("Source Port: % d \ n", source_port ); Printf ("Destination Port: % d \ n", destination_port ); Switch (destination_port) { Case 80: Printf ("the upper layer protocol is HTTP \ n "); Break; Case 21: Printf ("the upper-layer protocol is the FTP protocol \ n "); Break; Case 23: Printf ("the upper-layer protocol is the TELNET protocol \ n "); Break; Case 25: Printf ("the upper-layer protocol is SMTP protocol \ n "); Break; Case 110: Printf ("POP3 protocol \ n "); Break; Default: Break; } Printf ("sequence code: % u \ n", sequence ); Printf ("Confirmation Number: % u \ n", acknowledgement ); Printf ("Header Length: % d \ n", header_length ); Printf ("retain: % d \ n", tcp_protocol-> tcp_reserved ); Printf ("tag :"); If (flags & 0x08) Printf ("PSH "); If (flags & 0x10) Printf ("ACK "); If (flags & 0x02) Printf ("SYN "); If (flags & 0x20) Printf ("URG "); If (flags & 0x01) Printf ("FIN "); If (flags & 0x04) Printf ("RST "); Printf ("\ n "); Printf ("window size: % d \ n", windows ); Printf ("checksum: % d \ n", checksum ); Printf ("Emergency pointer: % d \ n", urgent_pointer ); } /* ========================================================== ========================================================== ======================================================== The following describes the UPD protocol functions. ========================================================== ========================================================== ======================================================== */ Void udp_protocol_packet_callback (u_char * packet_content) { Struct udp_header * udp_protocol; U_short source_port; U_short destination_port; U_short length; Udp_protocol = (struct udp_header *) (packet_content + 20 ); Source_port = ntohs (udp_protocol-> udp_source_port ); /* Obtain the source port number */ Destination_port = ntohs (udp_protocol-> udp_destination_port ); /* Obtain the destination port number */ Length = ntohs (udp_protocol-> udp_length ); Printf ("---------- UDP protocol header ---------- \ n "); Printf ("Source Port: % d \ n", source_port ); Printf ("Destination Port: % d \ n", destination_port ); Switch (destination_port) { Case 138: Printf ("NETBIOS datainservice \ n "); Break; Case 137: Printf ("NETBIOS Name Service \ n "); Break; Case 139: Printf ("NETBIOS session service \ n "); Break; Case 53: Printf ("name-domain server \ n "); Break; Default: Break; } Printf ("length: % d \ n", length ); Printf ("checksum: % d \ n", ntohs (udp_protocol-> udp_checksum )); } /* ========================================================== ========================================================== ======================================================== The following is a function for analyzing the IP protocol. ========================================================== ========================================================== ======================================================== */ Void ip_protocol_packet_callback (u_char * packet_content) { Struct ip_header * ip_protocol; U_int header_length; U_int offset; U_char tos; Unsigned short checksum; Printf ("---------- IP protocol header ---------- \ n "); Ip_protocol = (struct ip_header *) (packet_content ); Checksum = ntohs (ip_protocol-> ip_checksum ); /* Get the checksum */ Header_length = ip_protocol-> ip_header_length * 4; /* Obtain the header length */ Tos = ip_protocol-> ip_tos; Offset = ntohs (ip_protocol-> ip_off ); Printf ("IP version: % d \ n", ip_protocol-> ip_version ); Printf ("Header Length: % d \ n", header_length ); Printf ("TOS: % d \ n", tos ); Printf ("total length: % d \ n", ntohs (ip_protocol-> ip_length )); Printf ("identifier: % d \ n", ntohs (ip_protocol-> ip_id )); Printf ("offset: % d \ n", (offset & 0x1fff) * 8 ); Printf ("survival time: % d \ n", ip_protocol-> ip_ttl ); Printf ("Protocol: % d \ n", ip_protocol-> ip_protocol ); Switch (ip_protocol-> ip_protocol)/* determine the upper-layer protocol type */ { Case 6: Printf ("the upper layer protocol is TCP \ n "); Break; Case 17: Printf ("UDP \ n "); Break; Case 1: Printf ("the upper layer protocol is ICMP \ n "); Break; Default: Break; } Printf ("checksum: % d \ n", checksum ); Printf ("Source IP Address: % s \ n", inet_ntoa (ip_protocol-> ip_souce_address )); Printf ("Destination IP Address: % s \ n", inet_ntoa (ip_protocol-> ip_destination_address )); Switch (ip_protocol-> ip_protocol) { Case 17: Udp_protocol_packet_callback (packet_content ); Break; /* When the upper-layer protocol is UDP, call the analysis function of UDP */ Case 6: Tcp_protocol_packet_callback (packet_content ); Break; /* When the upper-layer protocol is TCP, call and analyze the functions of TCP */ Case 1: Icmp_protocol_packet_callback (packet_content ); Break; /* When the upper-layer protocol is ICMP, call the function for analyzing ICMP */ Default: Break; } } /* ========================================================== ========================================================== ======================================================== The following is the callback function. ========================================================== ========================================================== ======================================================== */ Void ip_callback (struct ip * a_packet, int len) { Ip_protocol_packet_callback (a_packet ); /* Call the function for analyzing the IP protocol */ } /* ========================================================== ========================================================== ======================================================== Main Function ========================================================== ========================================================== ======================================================== */ Void main () { If (! Nids_init ()) /* Initialize Libnids */ { Printf ("error: % s \ n", nids_errbuf ); Exit (1 ); } Nids_register_ip_frag (ip_callback ); /* Register and analyze the callback function of the IP protocol */ Nids_run (); /* Enter the cyclic packet capture status */ }