diff options
| -rw-r--r-- | checkalias.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/checkalias.c b/checkalias.c new file mode 100644 index 00000000..413b4047 --- /dev/null +++ b/checkalias.c @@ -0,0 +1,73 @@ +#include <stdio.h> +#include <string.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <arpa/inet.h> +#include <netdb.h> +#include "fetchmail.h" + + +int is_ip_alias(const char *name1,const char *name2) +/* Given two hostnames as arguments, returns TRUE if they + * have at least one IP address in common. + * It is meant to be called by the is_host_alias() function in driver.c + * No check is done on errors returned by gethostbyname, + * the calling function does them. + */ + { + + typedef unsigned char address_t[sizeof (struct in_addr)]; + typedef struct _address_e { struct _address_e *next; + address_t address; + } address_e; + + address_e *host_a_addr, *host_b_addr,*dummy_addr; + + int i; + + struct hostent *hp; + + char **p; + + hp = gethostbyname(name1); + + dummy_addr = (address_e *)NULL; + + for (i=0,p = hp->h_addr_list; *p != 0; i++,p++) { + struct in_addr in; + (void) memcpy(&in.s_addr, *p, sizeof (in.s_addr)); + host_a_addr = (address_e *)xmalloc(sizeof( address_e)); + memset (host_a_addr,0, sizeof (address_e)); + host_a_addr->next = dummy_addr; + (void) memcpy(&host_a_addr->address, *p, sizeof (in.s_addr)); + dummy_addr = host_a_addr; + } + + + hp = gethostbyname(name2); + + dummy_addr = (address_e *)NULL; + + for (i=0,p = hp->h_addr_list; *p != 0; i++,p++) { + struct in_addr in; + (void) memcpy(&in.s_addr, *p, sizeof (in.s_addr)); + host_b_addr = (address_e *)xmalloc(sizeof( address_e)); + memset (host_b_addr,0, sizeof (address_e)); + host_b_addr->next = dummy_addr; + (void) memcpy(&host_b_addr->address, *p, sizeof (in.s_addr)); + dummy_addr = host_b_addr; + } + + while (host_a_addr) { + while (host_b_addr) { + + if (!memcmp(host_b_addr->address,host_a_addr->address, sizeof (address_t))) return (TRUE); + + host_b_addr = host_b_addr->next; + } + host_a_addr = host_a_addr->next; + } +return (FALSE); +} + |