diff options
Diffstat (limited to 'netcon/RPC.c')
| -rw-r--r-- | netcon/RPC.c | 70 |
1 files changed, 38 insertions, 32 deletions
diff --git a/netcon/RPC.c b/netcon/RPC.c index 46f09401..ab51e28b 100644 --- a/netcon/RPC.c +++ b/netcon/RPC.c @@ -6,16 +6,21 @@ #include <sys/syscall.h> #include <fcntl.h> +#include <dlfcn.h> #include <stdint.h> #include <sys/socket.h> #include <strings.h> #include "RPC.h" -#define RPC_FD 1023 #define SERVICE_CONNECT_ATTEMPTS 30 -static int instance_count; +#define CONNECT_SIG int __fd, const struct sockaddr * __addr, socklen_t __len +#define SOCKET_SIG int socket_family, int socket_type, int protocol + +static int (*realconnect)(CONNECT_SIG) = 0; +static int (*realsocket)(SOCKET_SIG) = 0; + static int rpc_count; static pthread_mutex_t lock; @@ -63,30 +68,40 @@ int get_retval(int rpc_sock) return -1; } +int load_symbols_rpc() +{ + #ifdef NETCON_INTERCEPT + realsocket = dlsym(RTLD_NEXT, "socket"); + realconnect = dlsym(RTLD_NEXT, "connect"); + if(!realconnect || !realsocket) + return -1; + #endif + return 1; +} + int rpc_join(const char * sockname) { + if(!load_symbols_rpc()) + return -1; + struct sockaddr_un addr; int conn_err = -1, attempts = 0; - memset(&addr, 0, sizeof(addr)); addr.sun_family = AF_UNIX; strncpy(addr.sun_path, sockname, sizeof(addr.sun_path)-1); int sock; - if((sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0){ + if((sock = realsocket(AF_UNIX, SOCK_STREAM, 0)) < 0){ fprintf(stderr, "Error while creating RPC socket\n"); return -1; } while((conn_err != 0) && (attempts < SERVICE_CONNECT_ATTEMPTS)){ - if((conn_err = connect(sock, (struct sockaddr*)&addr, sizeof(addr))) != 0) { + if((conn_err = realconnect(sock, (struct sockaddr*)&addr, sizeof(addr))) != 0) { fprintf(stderr, "Error while connecting to RPC socket. Re-attempting...\n"); sleep(1); } - else { - //int newfd = dup2(sock, RPC_FD-instance_count); - //close(sock); + else return sock; - } attempts++; } return -1; @@ -95,36 +110,24 @@ int rpc_join(const char * sockname) /* * Send a command to the service */ -int rpc_send_command(int cmd, int forfd, void *data, int len) +int rpc_send_command(char *path, int cmd, int forfd, void *data, int len) { pthread_mutex_lock(&lock); char c, padding[] = {0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89}; - char cmdbuf[BUF_SZ], magic[TOKEN_SIZE], metabuf[BUF_SZ]; - memcpy(magic+MAGIC_SIZE, padding, TOKEN_SIZE); - uint64_t magic_num; - + char cmdbuf[BUF_SZ], CANARY[TOKEN_SIZE], metabuf[BUF_SZ]; + memcpy(CANARY+CANARY_SIZE, padding, TOKEN_SIZE); + uint64_t canary_num; // ephemeral RPC socket used only for this command - int rpc_sock = rpc_join("/root/dev/ztest/nc_e5cd7a9e1c3511dd"); + int rpc_sock = rpc_join(path); // Generate token int fdrand = open("/dev/urandom", O_RDONLY); - read(fdrand, &magic, MAGIC_SIZE); - memcpy(&magic_num, magic, MAGIC_SIZE); + read(fdrand, &CANARY, CANARY_SIZE); + memcpy(&canary_num, CANARY, CANARY_SIZE); cmdbuf[CMD_ID_IDX] = cmd; - memcpy(&cmdbuf[MAGIC_IDX], &magic_num, MAGIC_SIZE); + memcpy(&cmdbuf[CANARY_IDX], &canary_num, CANARY_SIZE); memcpy(&cmdbuf[STRUCT_IDX], data, len); - // Format: [sig_byte] + [cmd_id] + [magic] + [meta] + [payload] - #ifdef VERBOSE - /* - #define IDX_PID 0 - #define IDX_TID sizeof(pid_t) - #define IDX_COUNT IDX_TID + sizeof(pid_t) - #define IDX_TIME IDX_COUNT + sizeof(int) - #define IDX_CMD IDX_TIME + 20 // 20 being the length of the timestamp string - #define IDX_PAYLOAD IDX_TIME + sizeof(char) - */ - /* [pid_t] [pid_t] [rpc_count] [int] [...] */ memset(metabuf, 0, BUF_SZ); pid_t pid = syscall(SYS_getpid); pid_t tid = syscall(SYS_gettid); @@ -141,7 +144,7 @@ int rpc_send_command(int cmd, int forfd, void *data, int len) memcpy(&metabuf[IDX_TIME], ×tring, 20 ); /* timestamp */ #endif /* Combine command flag+payload with RPC metadata */ - memcpy(&metabuf[IDX_PAYLOAD], cmdbuf, len + 1 + MAGIC_SIZE); + memcpy(&metabuf[IDX_PAYLOAD], cmdbuf, len + 1 + CANARY_SIZE); // Write RPC int n_write = write(rpc_sock, &metabuf, BUF_SZ); @@ -152,7 +155,10 @@ int rpc_send_command(int cmd, int forfd, void *data, int len) // Write token to corresponding data stream read(rpc_sock, &c, 1); if(c == 'z' && n_write > 0 && forfd > -1){ - int w = send(forfd, &magic, TOKEN_SIZE, 0); + if(send(forfd, &CANARY, TOKEN_SIZE, 0) < 0) { + fprintf(stderr,"unable to write canary to stream\n"); + return -1; + } } // Process response from service int ret = ERR_OK; @@ -263,4 +269,4 @@ ssize_t sock_fd_read(int sock, void *buf, ssize_t bufsize, int *fd) } } return size; -} +}
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