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Add working http client

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This commit is contained in:
Ivaylo Ivanov 2018-11-05 17:46:15 +01:00
parent 69612815b6
commit 2f552e5ad4
3 changed files with 142 additions and 10 deletions
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4
.gitignore vendored
View File

@ -1,3 +1,7 @@
.vscode/
*.out
*.o
*.html
!public/*.html
http/client
http/server

6
http/Makefile
View File

@ -21,7 +21,7 @@ install:
cp $(TARGET_2) /usr/local/bin/myhttp-$(TARGET_2)
clean:
$(RM) $(TARGET_1).o
$(RM) $(TARGET_1)
$(RM) $(TARGET_2).o
$(RM) $(TARGET_2)
$(RM) $(TARGET_2)
$(RM) *.o
$(RM) *.html

142
http/client.c
View File

@ -28,6 +28,8 @@
#include "shared/http.h"
static struct addrinfo* get_host_info(const char *hostname, char *port);
static int create_socket(struct addrinfo* config);
static void process_response(char reply[sizeof(int32_t)], char *ofile, char *dir);
int main(int argc, char *argv[]) {
check_opts_number(argc);
@ -79,13 +81,41 @@ int main(int argc, char *argv[]) {
url = argv[optind];
}
const char *full_url = strstr(url, "http://") + 7; //< the full url starts after http://
const char *path = strstr(full_url, "/");
const char *hostname = "google.com"; //< TODO: Change this later
char *base_url = strstr(url, "http://") + 7; //< the base url starts after http://
struct addrinfo* res = get_host_info(hostname, port); //< Check if the address is resolvable
const char *path = strstr(base_url, "/");
if(path == NULL) path = "/"; //< Set the root path if there is none
freeaddrinfo(res); //< Free the addrinfo struct
const char *hostname = strtok(base_url, ";/?:@=&"); //< Get the FQDN of the remote
struct addrinfo* config = get_host_info(hostname, port); //< Check if the address is resolvable
char header[strlen(base_url) + 100]; //< Create a variable to store the header
snprintf(header, sizeof header, "GET %s HTTP/1.1\r\nHost: %s\r\nConnection: close\r\n\r\n", path, hostname); //< Build the header
int sockfd = create_socket(config);
if (connect(sockfd, config -> ai_addr, config -> ai_addrlen) == -1) { //< Connect to the host
(void) fprintf(stderr, "ERROR: Failure connecting to the server.\n");
exit(EXIT_FAILURE);
}
if((send(sockfd, header, strlen(header), 0)) < 0) { //< Send the GET request
(void) fprintf(stderr, "ERROR: Failure sending the request to the server.\n");
exit(EXIT_FAILURE);
}
char reply[sizeof(int32_t)]; //< Set the variable to hold the server response. Set to a big length
if((recv(sockfd, reply, strlen(reply) - 1, 0)) < 0) { //< Receive response from the remote (-1 for the trailing terminating char)
(void) fprintf(stderr, "ERROR: Did not receive response from the remote.\n");
exit(EXIT_FAILURE);
}
process_response(reply, ofile, dir);
freeaddrinfo(config); //< Free the addrinfo struct
}
static void print_usage(void) {
@ -115,7 +145,7 @@ static void check_opts_number(int argc) {
/**
* @brief Function to check if the address is resolvable by the client
* @details Checks if the address is resolvable by the client.
* If the address is resolvable, it writes the result to res
* If the address is resolvable, it returns the result
* If the address is not resolvable, it exits with an error
* @param
* hostname - The address to be resolved
@ -138,7 +168,6 @@ static struct addrinfo* get_host_info(const char *hostname, char *port) {
(void) fprintf(stderr, "ERROR: %s\n", gai_strerror(err));
exit(EXIT_FAILURE); //< Exit if there is an error
}
if(res == NULL) {
(void) fprintf(stderr, "ERROR: Could not resolve address %s\n", hostname);
exit(EXIT_FAILURE); //< Exit if the address is not resolved
@ -146,3 +175,102 @@ static struct addrinfo* get_host_info(const char *hostname, char *port) {
return res;
}
/**
* @brief Function to create a socker using the supplied configuration
* @details Creates a socket using the supplied configuration
* If there was no error, it returns the socket
* If there was an error, it exits and displays an error message
* @param config - The the configuration to be used for the socket creation
* @return sockfd - The socket obtained from the socket creation
**/
static int create_socket(struct addrinfo* config) {
int sockfd = socket(config->ai_family, config->ai_socktype, config->ai_protocol);
if(sockfd < 0) {
(void) fprintf(stderr, "ERROR: Socket creation failed.\n");
exit(EXIT_FAILURE);
}
return sockfd;
}
/**
* @brief Function to process the response of the remote host
* @details Processes the reply according to its' content and the ofile and dir parameters
* The function checks the response code does the following:
* - if the reponse code is invalid, it exits with an error
* - if the response code is different from 200, it prints the whole response and exits with status 3
* - if the response code is 200, it prints it to the console or saves it as a file
* If there was an error, it exits and displays an error message
* @param config - The the configuration to be used for the socket creation
* @return null
**/
static void process_response(char reply[sizeof(int32_t)], char *ofile, char *dir) {
char *http_version = "HTTP/1.1";
if(strncmp(reply, http_version, strlen(http_version)) == 0) { //< Check if the remote gives a correct response header
char cresponse_code[3]; //< Array for the response code. Response codes are always 3 digits long
strncpy(cresponse_code ,strstr(reply, "HTTP/1.1 ") + sizeof(http_version) + 1, 3); //< Get the response code as string.
int response_code = strtol(cresponse_code, NULL, 10); //< Get the response code as integer
if(response_code == 0) {
fprintf(stderr, "ERROR: Protocol error.\n");
exit(EXIT_FAILURE);
} else if (response_code != 200) {
printf("%s\n", strtok(reply, "\r\n")); //< Get the first line
exit(EXIT_SUCCESS);
}
char *body = strstr(reply, "\r\n\r\n") + 4;
if(ofile == NULL && dir == NULL) printf("%s", body); //< Print the body of the response
else {
if(ofile != NULL) {
FILE *out = NULL;
out = fopen(ofile, "w");
if(out == NULL) {
(void) fprintf(stderr, "ERROR: Could not open ./%s for writing.", ofile);
exit(EXIT_FAILURE);
} else {
fprintf(out, "%s", body);
fclose(out);
printf("File ./%s successfully written.\n", ofile);
exit(EXIT_SUCCESS);
}
} else if(dir != NULL) {
FILE *out = NULL;
char path[sizeof(dir) + 100];
if(dir[strlen(dir) - 1] == '/')
snprintf(path, sizeof path, "%sresult.html", dir);
else
snprintf(path, sizeof path, "%s/result.html", dir);
out = fopen(path, "w"); //< Open <path>/result.html for writing
if(out == NULL) {
if(dir[strlen(dir) - 1] == '/')
(void) fprintf(stderr, "ERROR: Could not open %sresult.html for writing.\n", dir);
else
(void) fprintf(stderr, "ERROR: Could not open %s/result.html for writing.\n", dir);
exit(EXIT_FAILURE);
} else {
fprintf(out, "%s", body);
fclose(out);
if(dir[strlen(dir) - 1] == '/')
printf("File %sresult.html successfully written.\n", dir);
else
printf("File %s/result.html successfully written.\n", dir);
exit(EXIT_SUCCESS);
}
}
}
} else {
fprintf(stderr, "ERROR: Protocol error.\n");
exit(EXIT_FAILURE);
}
}