android2.3.4----7.adb分析(未完成)

一. android板子上的adbd

1. Androi.mk与编译

LOCAL_PATH:= (callmy−dir)include(CLEAR_VARS)

LOCAL_SRC_FILES := \

adb.c \

fdevent.c \

transport.c \

transport_local.c \

transport_usb.c \

sockets.c \

services.c \

file_sync_service.c \

jdwp_service.c \

framebuffer_service.c \

remount_service.c \

usb_linux_client.c \

log_service.c \

utils.c

LOCAL_CFLAGS := -O2 -g -DADB_HOST=0 -Wall -Wno-unused-parameter

LOCAL_CFLAGS += -D_XOPEN_SOURCE -D_GNU_SOURCE

LOCAL_CFLAGS += -DANDROID_GADGET=1

LOCAL_MODULE := adbd

LOCAL_FORCE_STATIC_EXECUTABLE := true

LOCAL_MODULE_PATH := (TARGETROOTOUTSBIN)LOCALUNSTRIPPEDPATH:=(TARGET_ROOT_OUT_SBIN_UNSTRIPPED)

LOCAL_STATIC_LIBRARIES := libcutils libc

include $(BUILD_EXECUTABLE)

a. 编译adbd

mmm ./system/core/adb

b.生成的adb 的目录

out/target/product/OK6410/root/sbin/adbd

c. 临时文件的目录

out/target/product/OK6410/obj/EXECUTABLES/adbd_intermediates/

2.

在system/core/adb/adb.c中

int main(int argc, char **argv)

{

adb_trace_init();

if ADB_HOST

else //在Android.mk中定义了ADB_HOST=0

if((argc > 1) && (!strcmp(argv[1],"recovery"))) {
adb_device_banner = "recovery";
recovery_mode = 1;
}

start_device_log();
return adb_main(0, DEFAULT_ADB_PORT);

endif

}

二. host 端的adb

1. Android.mk与编译adb

LOCAL_PATH:= (callmy−dir)include(CLEAR_VARS)

USB_SRCS := usb_linux.c

EXTRA_SRCS := get_my_path_linux.c

LOCAL_LDLIBS += -lrt -lncurses -lpthread

LOCAL_SRC_FILES := \

adb.c \

console.c \

transport.c \

transport_local.c \

transport_usb.c \

commandline.c \

adb_client.c \

sockets.c \

services.c \

file_sync_client.c \

(EXTRASRCS) (USB_SRCS) \

utils.c \

usb_vendors.c

LOCAL_SRC_FILES += fdevent.c

LOCAL_CFLAGS += -O2 -g -DADB_HOST=1 -Wall -Wno-unused-parameter

LOCAL_CFLAGS += -D_XOPEN_SOURCE -D_GNU_SOURCE

LOCAL_MODULE := adb

LOCAL_STATIC_LIBRARIES := libzipfile libunz (EXTRASTATICLIBS)ifeq((USE_SYSDEPS_WIN32),)

LOCAL_STATIC_LIBRARIES += libcutils

endif

include $(BUILD_HOST_EXECUTABLE)

(calldist−for−goals,droid,(LOCAL_BUILT_MODULE))

a. 编译adb

mmm ./system/core/adb

b.生成的adb 的目录

out/host/linux-x86/bin/adb

c. 临时文件的目录

out/host/linux-x86/obj/EXECUTABLES/adb_intermediates/

2.

在system/core/adb/adb.c中

int main(int argc, char **argv)

{

adb_trace_init(); //只对adbd有效

//在Android.mk中定义了ADB_HOST=1

if ADB_HOST

adb_sysdeps_init();  //空函数
return adb_commandline(argc - 1, argv + 1);

else

endif

}

2.1 adb devices过程

传给adb_commandline的参数是adb命令的参数

main

–>adb_commandline

在system/core/adb/commandline.c中

int adb_commandline(int argc, char **argv)

{

if(!strcmp(argv[0], “devices”)) {

char *tmp;

snprintf(buf, sizeof buf, “host:%s”, argv[0]);

tmp = adb_query(buf); //buf=”host:devices”

if(tmp) {

printf(“List of devices attached \n”);

printf(“%s\n”, tmp);

return 0;
} else {

return 1;

}

}

}

main

–>adb_commandline

–> adb_query

在system/core/adb/adb_client.c中

char *adb_query(const char *service)

{

char buf[5];

unsigned n;

char *tmp;

int fd = adb_connect(service);
readx(fd, buf, 4);

buf[4] = 0;
n = strtoul(buf, 0, 16);
if(n > 1024) goto oops;

tmp = malloc(n + 1);
if(tmp == 0) goto oops;

if(readx(fd, tmp, n) == 0) {
tmp
= 0;
adb_close(fd);
return tmp;
}
free(tmp);

oops:

adb_close(fd);

return 0;
}

main

–>adb_commandline

–> adb_query

–> adb_connect

在system/core/adb/adb_client.c中

int adb_connect(const char *service)

{

int fd = _adb_connect(“host:version”); //如果是第一次打开,则打开失败,下一步要启动server

if(fd == -2) { //打印的这段信息,很熟悉

fprintf(stdout,”* daemon not running. starting it now on port %d *\n”, __adb_server_port);

start_server:

if(launch_server(__adb_server_port)) {

fprintf(stderr,”* failed to start daemon *\n”);

return -1;

} else {

fprintf(stdout,”* daemon started successfully *\n”);

}

/* give the server some time to start properly and detect devices */

adb_sleep_ms(3000);

// fall through to _adb_connect

} else {

// if server was running, check its version to make sure it is not out of date

char buf[100];

int n;

int version = ADB_SERVER_VERSION - 1;

// if we have a file descriptor, then parse version result
if(fd >= 0) {
if(readx(fd, buf, 4)) goto error;

buf[4] = 0;
n = strtoul(buf, 0, 16);
if(n > (int)sizeof(buf)) goto error;
if(readx(fd, buf, n)) goto error;
adb_close(fd);

if (sscanf(buf, "%04x", &version) != 1) goto error;
} else {
// if fd is -1, then check for "unknown host service",
// which would indicate a version of adb that does not support the version command
if (strcmp(__adb_error, "unknown host service") != 0)
return fd;
}

if(version != ADB_SERVER_VERSION) {
printf("adb server is out of date. killing...\n");
fd = _adb_connect("host:kill");
adb_close(fd);

/* XXX can we better detect its death? */
adb_sleep_ms(2000);
goto start_server;
}
}

// if the command is start-server, we are done.
if (!strcmp(service, "host:start-server"))
return 0;

fd = _adb_connect(service);
if(fd == -2) {
fprintf(stderr,"** daemon still not running");
}

return fd;

error:

adb_close(fd);

return -1;

}

main

–>adb_commandline

–> adb_query

–> adb_connect

–> _adb_connect

在system/core/adb/adb_client.c中

int _adb_connect(const char *service) //server=”host:version”

{

char tmp[5];

int len;

int fd;

D(“_adb_connect: %s\n”, service);

len = strlen(service);

snprintf(tmp, sizeof tmp, “%04x”, len);

fd = socket_loopback_client(__adb_server_port, SOCK_STREAM);
if(fd < 0) {  //如果是开机后第一次打开adb,没有启动server则打开失败
strcpy(__adb_error, "cannot connect to daemon");
return -2;
}

}

main

–>adb_commandline

–> adb_query

–> adb_connect

–> _adb_connect

–> socket_loopback_client

在system/core/adb/adb_client.c中

int socket_loopback_client(int port, int type)

{

struct sockaddr_in addr;

socklen_t alen;

int s;

memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);

s = socket(AF_INET, type, 0);

if(connect(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
close(s);
return -1;
}

return s;

}

连接到本地的__adb_server_port=5037端口,如果不成功,即服务端没有打开,则返回-1.

int launch_server(int server_port)

{

ifdef HAVE_WIN32_PROC //这儿区分window与linux

elif defined(HAVE_FORKEXEC) //linux have fork exec

char path[PATH_MAX];
int fd[2];

pipe(fd));  //创建管道
get_my_path(path, PATH_MAX);  //获取己执行的adb的路径,为下一步启动adb server作准备
pid_t pid = fork();
if (pid == 0) {     //子进程
adb_close(fd[0]);
dup2(fd[1], STDERR_FILENO);     //将管道的输出fd[1]重定向到STDERR,这样好把错误信息打印出来
adb_close(fd[1]);

// child process
int result = execl(path, "adb", "fork-server", "server", NULL);
// this should not return
fprintf(stderr, "OOPS! execl returned %d, errno: %d\n", result, errno);
} else {
// parent side of the fork

char temp[3];

temp[0] = 'A'; temp[1] = 'B'; temp[2] = 'C';
// wait for the "OK\n" message
adb_close(fd[1]);
int ret = adb_read(fd[0], temp, 3);
adb_close(fd[0]);
if (ret < 0) {
fprintf(stderr, "could not read ok from ADB Server, errno = %d\n", errno);
return -1;
}
if (ret != 3 || temp[0] != 'O' || temp[1] != 'K' || temp[2] != '\n') {
fprintf(stderr, "ADB server didn't ACK\n" );
return -1;
}

setsid();
}

else

error “cannot implement background server start on this platform”

endif

return 0;

}

通过pid找到可执行文件所在的路径

void get_my_path(char *exe, size_t maxLen)

{

char proc[64];

snprintf(proc, sizeof proc, “/proc/%d/exe”, getpid());

int err = readlink(proc, exe, maxLen - 1);

if(err > 0) {

exe[err] = ‘\0’;

} else {

exe[0] = ‘\0’;

}

}

cong@ubuntu:/tmpls−l/proc/2255/lrwxrwxrwx1congroot0Jan311:12exe−>/tmp/main这个/proc/(pid)/exe是一个软链接指向可执行文件所在的路径.

adb start-server

adb kill-server

adb devices

adb push

adb pull

adb uninstall

adb install