第5课第4节_Binder系统_C程序示例_测试与总结
这个zImage_nfs是通过下面编译出来的
上机测试:
a. 烧写非android系统, 比如QT
b. 重新编译内核让它支持NFS, 更新板上内核
make menuconfig
File systems --->
[*] Network File Systems --->
<*> NFS client support
[*] NFS client support for NFS version 3
[*] NFS client support for the NFSv3 ACL protocol extension
[*] NFS client support for NFS version 4
[*] NFS client support for NFSv4.1 (EXPERIMENTAL)
[*] Root file system on NFS
[*] Use the legacy NFS DNS resolver
[*] Use the new idmapper upcall routine
make zImage
c. mount nfs, 运行service_manager, test_server, test_client
mount -t nfs -o nolock 192.168.1.123:/work /mnt
./service_manager &
./test_server &
./test_client hello
./test_client hello weidongshan
git clone https://github.com/weidongshan/APP_0003_Binder_C_App.git
git checkout v4 // 添加了goodbye服务
test_client.c
/* Copyright 2008 The Android Open Source Project */ #include <stdio.h> #include <stdlib.h> #include <errno.h> #include <linux/types.h> #include<stdbool.h> #include <string.h> #include <private/android_filesystem_config.h> #include "binder.h" #include "test_server.h" uint32_t svcmgr_lookup(struct binder_state *bs, uint32_t target, const char *name) { uint32_t handle; unsigned iodata[512/4]; struct binder_io msg, reply; bio_init(&msg, iodata, sizeof(iodata), 4); bio_put_uint32(&msg, 0); // strict mode header bio_put_string16_x(&msg, SVC_MGR_NAME); bio_put_string16_x(&msg, name); if (binder_call(bs, &msg, &reply, target, SVC_MGR_CHECK_SERVICE)) return 0; handle = bio_get_ref(&reply); if (handle) binder_acquire(bs, handle); binder_done(bs, &msg, &reply); return handle; } struct binder_state *g_bs; uint32_t g_hello_handle; uint32_t g_goodbye_handle; void sayhello(void) { unsigned iodata[512/4]; struct binder_io msg, reply; /* 构造binder_io */ bio_init(&msg, iodata, sizeof(iodata), 4); bio_put_uint32(&msg, 0); // strict mode header /* 放入参数 */ /* 调用binder_call */ if (binder_call(g_bs, &msg, &reply, g_hello_handle, HELLO_SVR_CMD_SAYHELLO)) return ; /* 从reply中解析出返回值 */ binder_done(g_bs, &msg, &reply); } int sayhello_to(char *name) { unsigned iodata[512/4]; struct binder_io msg, reply; int ret; /* 构造binder_io */ bio_init(&msg, iodata, sizeof(iodata), 4); bio_put_uint32(&msg, 0); // strict mode header /* 放入参数 */ bio_put_string16_x(&msg, name); /* 调用binder_call */ if (binder_call(g_bs, &msg, &reply, g_hello_handle, HELLO_SVR_CMD_SAYHELLO_TO)) return 0; /* 从reply中解析出返回值 */ ret = bio_get_uint32(&reply); binder_done(g_bs, &msg, &reply); return ret; } void saygoodbye(void) { unsigned iodata[512/4]; struct binder_io msg, reply; /* 构造binder_io */ bio_init(&msg, iodata, sizeof(iodata), 4); bio_put_uint32(&msg, 0); // strict mode header /* 放入参数 */ /* 调用binder_call */ if (binder_call(g_bs, &msg, &reply, g_goodbye_handle, GOODBYE_SVR_CMD_SAYGOODBYE)) return ; /* 从reply中解析出返回值 */ binder_done(g_bs, &msg, &reply); } int saygoodbye_to(char *name) { unsigned iodata[512/4]; struct binder_io msg, reply; int ret; /* 构造binder_io */ bio_init(&msg, iodata, sizeof(iodata), 4); bio_put_uint32(&msg, 0); // strict mode header /* 放入参数 */ bio_put_string16_x(&msg, name); /* 调用binder_call */ if (binder_call(g_bs, &msg, &reply, g_goodbye_handle, GOODBYE_SVR_CMD_SAYGOODBYE_TO)) return 0; /* 从reply中解析出返回值 */ ret = bio_get_uint32(&reply); binder_done(g_bs, &msg, &reply); return ret; } /* ./test_client hello * ./test_client hello <name> */ int main(int argc, char **argv) { int fd; struct binder_state *bs; uint32_t svcmgr = BINDER_SERVICE_MANAGER; uint32_t handle; int ret; if (argc < 2){ fprintf(stderr, "Usage:\n"); fprintf(stderr, "%s <hello|goodbye>\n", argv[0]); fprintf(stderr, "%s <hello|goodbye> <name>\n", argv[0]); return -1; } bs = binder_open(128*1024); if (!bs) { fprintf(stderr, "failed to open binder driver\n"); return -1; } g_bs = bs; /* get service */ handle = svcmgr_lookup(bs, svcmgr, "goodbye"); if (!handle) { fprintf(stderr, "failed to get goodbye service\n"); return -1; } g_goodbye_handle = handle; fprintf(stderr, "Handle for goodbye service = %d\n", g_goodbye_handle); handle = svcmgr_lookup(bs, svcmgr, "hello"); if (!handle) { fprintf(stderr, "failed to get hello service\n"); return -1; } g_hello_handle = handle; fprintf(stderr, "Handle for hello service = %d\n", g_hello_handle); /* send data to server */ if (!strcmp(argv[1], "hello")) { if (argc == 2) { sayhello(); } else if (argc == 3) { ret = sayhello_to(argv[2]); fprintf(stderr, "get ret of sayhello_to = %d\n", ret); } } else if (!strcmp(argv[1], "goodbye")) { if (argc == 2) { saygoodbye(); } else if (argc == 3) { ret = saygoodbye_to(argv[2]); fprintf(stderr, "get ret of sayhello_to = %d\n", ret); } } binder_release(bs, handle); return 0; }
test_server.c
/* Copyright 2008 The Android Open Source Project */ #include <stdio.h> #include <stdlib.h> #include <errno.h> #include <linux/types.h> #include<stdbool.h> #include <string.h> #include <private/android_filesystem_config.h> #include "binder.h" #include "test_server.h" int svcmgr_publish(struct binder_state *bs, uint32_t target, const char *name, void *ptr) { int status; unsigned iodata[512/4]; struct binder_io msg, reply; bio_init(&msg, iodata, sizeof(iodata), 4); bio_put_uint32(&msg, 0); // strict mode header bio_put_string16_x(&msg, SVC_MGR_NAME); bio_put_string16_x(&msg, name); bio_put_obj(&msg, ptr); if (binder_call(bs, &msg, &reply, target, SVC_MGR_ADD_SERVICE)) return -1; status = bio_get_uint32(&reply); binder_done(bs, &msg, &reply); return status; } void sayhello(void) { static int cnt = 0; fprintf(stderr, "say hello : %d\n", cnt++); } int sayhello_to(char *name) { static int cnt = 0; fprintf(stderr, "say hello to %s : %d\n", name, cnt++); return cnt; } void saygoodbye(void) { static int cnt = 0; fprintf(stderr, "say goodbye : %d\n", cnt++); } int saygoodbye_to(char *name) { static int cnt = 0; fprintf(stderr, "say goodbye to %s : %d\n", name, cnt++); return cnt; } int hello_service_handler(struct binder_state *bs, struct binder_transaction_data *txn, struct binder_io *msg, struct binder_io *reply) { /* 根据txn->code知道要调用哪一个函数 * 如果需要参数, 可以从msg取出 * 如果要返回结果, 可以把结果放入reply */ /* sayhello * sayhello_to */ uint16_t *s; char name[512]; size_t len; uint32_t handle; uint32_t strict_policy; int i; // Equivalent to Parcel::enforceInterface(), reading the RPC // header with the strict mode policy mask and the interface name. // Note that we ignore the strict_policy and don't propagate it // further (since we do no outbound RPCs anyway). strict_policy = bio_get_uint32(msg); switch(txn->code) { case HELLO_SVR_CMD_SAYHELLO: sayhello(); return 0; case HELLO_SVR_CMD_SAYHELLO_TO: /* 从msg里取出字符串 */ s = bio_get_string16(msg, &len); if (s == NULL) { return -1; } for (i = 0; i < len; i++) name[i] = s[i]; name[i] = '\0'; /* 处理 */ i = sayhello_to(name); /* 把结果放入reply */ bio_put_uint32(reply, i); break; default: fprintf(stderr, "unknown code %d\n", txn->code); return -1; } return 0; } int goodbye_service_handler(struct binder_state *bs, struct binder_transaction_data *txn, struct binder_io *msg, struct binder_io *reply) { /* 根据txn->code知道要调用哪一个函数 * 如果需要参数, 可以从msg取出 * 如果要返回结果, 可以把结果放入reply */ /* sayhello * sayhello_to */ uint16_t *s; char name[512]; size_t len; uint32_t handle; uint32_t strict_policy; int i; // Equivalent to Parcel::enforceInterface(), reading the RPC // header with the strict mode policy mask and the interface name. // Note that we ignore the strict_policy and don't propagate it // further (since we do no outbound RPCs anyway). strict_policy = bio_get_uint32(msg); switch(txn->code) { case GOODBYE_SVR_CMD_SAYGOODBYE: saygoodbye(); return 0; case GOODBYE_SVR_CMD_SAYGOODBYE_TO: /* 从msg里取出字符串 */ s = bio_get_string16(msg, &len); if (s == NULL) { return -1; } for (i = 0; i < len; i++) name[i] = s[i]; name[i] = '\0'; /* 处理 */ i = saygoodbye_to(name); /* 把结果放入reply */ bio_put_uint32(reply, i); break; default: fprintf(stderr, "unknown code %d\n", txn->code); return -1; } return 0; } int test_server_handler(struct binder_state *bs, struct binder_transaction_data *txn, struct binder_io *msg, struct binder_io *reply) { if (txn->target.ptr == 123) return hello_service_handler(bs, txn, msg, reply); else if (txn->target.ptr == 124) return goodbye_service_handler(bs, txn, msg, reply); else return -1; } int main(int argc, char **argv) { int fd; struct binder_state *bs; uint32_t svcmgr = BINDER_SERVICE_MANAGER; uint32_t handle; int ret; bs = binder_open(128*1024); if (!bs) { fprintf(stderr, "failed to open binder driver\n"); return -1; } /* add service */ ret = svcmgr_publish(bs, svcmgr, "hello", (void *)123); if (ret) { fprintf(stderr, "failed to publish hello service\n"); return -1; } ret = svcmgr_publish(bs, svcmgr, "goodbye", (void *)124); if (ret) { fprintf(stderr, "failed to publish goodbye service\n"); } #if 0 while (1) { /* read data */ /* parse data, and process */ /* reply */ } #endif binder_loop(bs, test_server_handler); return 0; }
test_server.h
#ifndef _TEST_SERVER_H #define _TEST_SERVER_H #define HELLO_SVR_CMD_SAYHELLO 0 #define HELLO_SVR_CMD_SAYHELLO_TO 1 #define GOODBYE_SVR_CMD_SAYGOODBYE 0 #define GOODBYE_SVR_CMD_SAYGOODBYE_TO 1 #endif // _TEST_SERVER_H
service_manager.c
/* Copyright 2008 The Android Open Source Project */ #include <stdio.h> #include <stdlib.h> #include <errno.h> #include <fcntl.h> #include <linux/types.h> #include<stdbool.h> #include <private/android_filesystem_config.h> //#include <selinux/android.h> //#include <selinux/avc.h> #include "binder.h" #if 1 #define ALOGI(x...) fprintf(stderr, "svcmgr: " x) #define ALOGE(x...) fprintf(stderr, "svcmgr: " x) #else #define LOG_TAG "ServiceManager" #include <cutils/log.h> #endif uint32_t svcmgr_handle; const char *str8(const uint16_t *x, size_t x_len) { static char buf[128]; size_t max = 127; char *p = buf; if (x_len < max) { max = x_len; } if (x) { while ((max > 0) && (*x != '\0')) { *p++ = *x++; max--; } } *p++ = 0; return buf; } int str16eq(const uint16_t *a, const char *b) { while (*a && *b) if (*a++ != *b++) return 0; if (*a || *b) return 0; return 1; } static char *service_manager_context; static bool check_mac_perms(pid_t spid, const char *tctx, const char *perm, const char *name) { return true; } static bool check_mac_perms_from_getcon(pid_t spid, const char *perm) { return true; } static bool check_mac_perms_from_lookup(pid_t spid, const char *perm, const char *name) { return true; } static int svc_can_register(const uint16_t *name, size_t name_len, pid_t spid) { const char *perm = "add"; return check_mac_perms_from_lookup(spid, perm, str8(name, name_len)) ? 1 : 0; } static int svc_can_list(pid_t spid) { const char *perm = "list"; return check_mac_perms_from_getcon(spid, perm) ? 1 : 0; } static int svc_can_find(const uint16_t *name, size_t name_len, pid_t spid) { const char *perm = "find"; return check_mac_perms_from_lookup(spid, perm, str8(name, name_len)) ? 1 : 0; } struct svcinfo { struct svcinfo *next; uint32_t handle; struct binder_death death; int allow_isolated; size_t len; uint16_t name[0]; }; struct svcinfo *svclist = NULL; struct svcinfo *find_svc(const uint16_t *s16, size_t len) { struct svcinfo *si; for (si = svclist; si; si = si->next) { if ((len == si->len) && !memcmp(s16, si->name, len * sizeof(uint16_t))) { return si; } } return NULL; } void svcinfo_death(struct binder_state *bs, void *ptr) { struct svcinfo *si = (struct svcinfo* ) ptr; ALOGI("service '%s' died\n", str8(si->name, si->len)); if (si->handle) { binder_release(bs, si->handle); si->handle = 0; } } uint16_t svcmgr_id[] = { 'a','n','d','r','o','i','d','.','o','s','.', 'I','S','e','r','v','i','c','e','M','a','n','a','g','e','r' }; uint32_t do_find_service(struct binder_state *bs, const uint16_t *s, size_t len, uid_t uid, pid_t spid) { struct svcinfo *si; if (!svc_can_find(s, len, spid)) { ALOGE("find_service('%s') uid=%d - PERMISSION DENIED\n", str8(s, len), uid); return 0; } si = find_svc(s, len); //ALOGI("check_service('%s') handle = %x\n", str8(s, len), si ? si->handle : 0); if (si && si->handle) { if (!si->allow_isolated) { // If this service doesn't allow access from isolated processes, // then check the uid to see if it is isolated. uid_t appid = uid % AID_USER; if (appid >= AID_ISOLATED_START && appid <= AID_ISOLATED_END) { return 0; } } return si->handle; } else { return 0; } } int do_add_service(struct binder_state *bs, const uint16_t *s, size_t len, uint32_t handle, uid_t uid, int allow_isolated, pid_t spid) { struct svcinfo *si; //ALOGI("add_service('%s',%x,%s) uid=%d\n", str8(s, len), handle, // allow_isolated ? "allow_isolated" : "!allow_isolated", uid); if (!handle || (len == 0) || (len > 127)) return -1; if (!svc_can_register(s, len, spid)) { ALOGE("add_service('%s',%x) uid=%d - PERMISSION DENIED\n", str8(s, len), handle, uid); return -1; } si = find_svc(s, len); if (si) { if (si->handle) { ALOGE("add_service('%s',%x) uid=%d - ALREADY REGISTERED, OVERRIDE\n", str8(s, len), handle, uid); svcinfo_death(bs, si); } si->handle = handle; } else { si = malloc(sizeof(*si) + (len + 1) * sizeof(uint16_t)); if (!si) { ALOGE("add_service('%s',%x) uid=%d - OUT OF MEMORY\n", str8(s, len), handle, uid); return -1; } si->handle = handle; si->len = len; memcpy(si->name, s, (len + 1) * sizeof(uint16_t)); si->name[len] = '\0'; si->death.func = (void*) svcinfo_death; si->death.ptr = si; si->allow_isolated = allow_isolated; si->next = svclist; svclist = si; } ALOGI("add_service('%s'), handle = %d\n", str8(s, len), handle); binder_acquire(bs, handle); binder_link_to_death(bs, handle, &si->death); return 0; } int svcmgr_handler(struct binder_state *bs, struct binder_transaction_data *txn, struct binder_io *msg, struct binder_io *reply) { struct svcinfo *si; uint16_t *s; size_t len; uint32_t handle; uint32_t strict_policy; int allow_isolated; //ALOGI("target=%x code=%d pid=%d uid=%d\n", // txn->target.handle, txn->code, txn->sender_pid, txn->sender_euid); if (txn->target.handle != svcmgr_handle) return -1; if (txn->code == PING_TRANSACTION) return 0; // Equivalent to Parcel::enforceInterface(), reading the RPC // header with the strict mode policy mask and the interface name. // Note that we ignore the strict_policy and don't propagate it // further (since we do no outbound RPCs anyway). strict_policy = bio_get_uint32(msg); s = bio_get_string16(msg, &len); if (s == NULL) { return -1; } if ((len != (sizeof(svcmgr_id) / 2)) || memcmp(svcmgr_id, s, sizeof(svcmgr_id))) { fprintf(stderr,"invalid id %s\n", str8(s, len)); return -1; } switch(txn->code) { case SVC_MGR_GET_SERVICE: case SVC_MGR_CHECK_SERVICE: s = bio_get_string16(msg, &len); if (s == NULL) { return -1; } handle = do_find_service(bs, s, len, txn->sender_euid, txn->sender_pid); if (!handle) break; bio_put_ref(reply, handle); return 0; case SVC_MGR_ADD_SERVICE: s = bio_get_string16(msg, &len); if (s == NULL) { return -1; } handle = bio_get_ref(msg); allow_isolated = bio_get_uint32(msg) ? 1 : 0; if (do_add_service(bs, s, len, handle, txn->sender_euid, allow_isolated, txn->sender_pid)) return -1; break; case SVC_MGR_LIST_SERVICES: { uint32_t n = bio_get_uint32(msg); if (!svc_can_list(txn->sender_pid)) { ALOGE("list_service() uid=%d - PERMISSION DENIED\n", txn->sender_euid); return -1; } si = svclist; while ((n-- > 0) && si) si = si->next; if (si) { bio_put_string16(reply, si->name); return 0; } return -1; } default: ALOGE("unknown code %d\n", txn->code); return -1; } bio_put_uint32(reply, 0); return 0; } int main(int argc, char **argv) { struct binder_state *bs; bs = binder_open(128*1024); if (!bs) { ALOGE("failed to open binder driver\n"); return -1; } if (binder_become_context_manager(bs)) { ALOGE("cannot become context manager (%s)\n", strerror(errno)); return -1; } svcmgr_handle = BINDER_SERVICE_MANAGER; binder_loop(bs, svcmgr_handler); return 0; }
git checkout v5 // 改进
test_server.c 只修改了这个文件
/* Copyright 2008 The Android Open Source Project */ #include <stdio.h> #include <stdlib.h> #include <errno.h> #include <linux/types.h> #include<stdbool.h> #include <string.h> #include <private/android_filesystem_config.h> #include "binder.h" #include "test_server.h" int svcmgr_publish(struct binder_state *bs, uint32_t target, const char *name, void *ptr) { int status; unsigned iodata[512/4]; struct binder_io msg, reply; bio_init(&msg, iodata, sizeof(iodata), 4); bio_put_uint32(&msg, 0); // strict mode header bio_put_string16_x(&msg, SVC_MGR_NAME); bio_put_string16_x(&msg, name); bio_put_obj(&msg, ptr); if (binder_call(bs, &msg, &reply, target, SVC_MGR_ADD_SERVICE)) return -1; status = bio_get_uint32(&reply); binder_done(bs, &msg, &reply); return status; } void sayhello(void) { static int cnt = 0; fprintf(stderr, "say hello : %d\n", cnt++); } int sayhello_to(char *name) { static int cnt = 0; fprintf(stderr, "say hello to %s : %d\n", name, cnt++); return cnt; } void saygoodbye(void) { static int cnt = 0; fprintf(stderr, "say goodbye : %d\n", cnt++); } int saygoodbye_to(char *name) { static int cnt = 0; fprintf(stderr, "say goodbye to %s : %d\n", name, cnt++); return cnt; } int hello_service_handler(struct binder_state *bs, struct binder_transaction_data *txn, struct binder_io *msg, struct binder_io *reply) { /* 根据txn->code知道要调用哪一个函数 * 如果需要参数, 可以从msg取出 * 如果要返回结果, 可以把结果放入reply */ /* sayhello * sayhello_to */ uint16_t *s; char name[512]; size_t len; uint32_t handle; uint32_t strict_policy; int i; // Equivalent to Parcel::enforceInterface(), reading the RPC // header with the strict mode policy mask and the interface name. // Note that we ignore the strict_policy and don't propagate it // further (since we do no outbound RPCs anyway). strict_policy = bio_get_uint32(msg); switch(txn->code) { case HELLO_SVR_CMD_SAYHELLO: sayhello(); return 0; case HELLO_SVR_CMD_SAYHELLO_TO: /* 从msg里取出字符串 */ s = bio_get_string16(msg, &len); if (s == NULL) { return -1; } for (i = 0; i < len; i++) name[i] = s[i]; name[i] = '\0'; /* 处理 */ i = sayhello_to(name); /* 把结果放入reply */ bio_put_uint32(reply, i); break; default: fprintf(stderr, "unknown code %d\n", txn->code); return -1; } return 0; } int goodbye_service_handler(struct binder_state *bs, struct binder_transaction_data *txn, struct binder_io *msg, struct binder_io *reply) { /* 根据txn->code知道要调用哪一个函数 * 如果需要参数, 可以从msg取出 * 如果要返回结果, 可以把结果放入reply */ /* sayhello * sayhello_to */ uint16_t *s; char name[512]; size_t len; uint32_t handle; uint32_t strict_policy; int i; // Equivalent to Parcel::enforceInterface(), reading the RPC // header with the strict mode policy mask and the interface name. // Note that we ignore the strict_policy and don't propagate it // further (since we do no outbound RPCs anyway). strict_policy = bio_get_uint32(msg); switch(txn->code) { case GOODBYE_SVR_CMD_SAYGOODBYE: saygoodbye(); return 0; case GOODBYE_SVR_CMD_SAYGOODBYE_TO: /* 从msg里取出字符串 */ s = bio_get_string16(msg, &len); if (s == NULL) { return -1; } for (i = 0; i < len; i++) name[i] = s[i]; name[i] = '\0'; /* 处理 */ i = saygoodbye_to(name); /* 把结果放入reply */ bio_put_uint32(reply, i); break; default: fprintf(stderr, "unknown code %d\n", txn->code); return -1; } return 0; } int test_server_handler(struct binder_state *bs, struct binder_transaction_data *txn, struct binder_io *msg, struct binder_io *reply) { int (*handler)(struct binder_state *bs, struct binder_transaction_data *txn, struct binder_io *msg, struct binder_io *reply); handler = (int (*)(struct binder_state *bs, struct binder_transaction_data *txn, struct binder_io *msg, struct binder_io *reply))txn->target.ptr; //进行了数据类型转换 handler = txn->target.ptr return handler(bs, txn, msg, reply); } int main(int argc, char **argv) { int fd; struct binder_state *bs; uint32_t svcmgr = BINDER_SERVICE_MANAGER; uint32_t handle; int ret; bs = binder_open(128*1024); if (!bs) { fprintf(stderr, "failed to open binder driver\n"); return -1; } /* add service */ ret = svcmgr_publish(bs, svcmgr, "hello", hello_service_handler); if (ret) { fprintf(stderr, "failed to publish hello service\n"); return -1; } ret = svcmgr_publish(bs, svcmgr, "goodbye", goodbye_service_handler); if (ret) { fprintf(stderr, "failed to publish goodbye service\n"); } #if 0 while (1) { /* read data */ /* parse data, and process */ /* reply */ } #endif binder_loop(bs, test_server_handler); return 0; }
